README.rst

BigML Ruby Bindings          
===================== 

`BigML <https://bigml.com>`_ makes machine learning easy by taking care
of the details required to add data-driven decisions and predictive
power to your company. Unlike other machine learning services, BigML
creates
`beautiful predictive models <https://bigml.com/gallery/models>`_ that
can be easily understood and interacted with.
    
These BigML Ruby bindings allow you to interact with
`BigML.io <https://bigml.io/>`_, the API
for BigML. You can use it to easily create, retrieve, list, update, and
delete BigML resources (i.e., sources, datasets, models and,
predictions).

This module is licensed under the `Apache License, Version
2.0 <http://www.apache.org/licenses/LICENSE-2.0.html>`_. 

Support
-------

Please report problems and bugs to our `BigML.io issue
tracker <https://github.com/bigmlcom/io/issues>`_.

Discussions about the different bindings take place in the general
`BigML mailing list <http://groups.google.com/group/bigml>`_. Or join us
in our `Campfire chatroom <https://bigmlinc.campfirenow.com/f20a0>`_.

Supported Ruby Versions
-----------------------

-  Ruby 2.0.x
-  Ruby 2.1.x
-  Ruby 2.2.x
-  Ruby 2.3.x
-  Ruby 2.4.x

Dependencies
------------

- rest-client
- activesupport
- parsr
- pycall
- numo-narray

Installation
------------
.. code-block:: ruby

   gem "bigml", :git => "git://github.com/antoniomachine/bigml-ruby.git"

Inside of your Ruby program do:

.. code-block:: ruby
   
   require "bigml"

Running the Tests
-----------------
Download and run the test suit:

.. code-block:: bash

  git clone git@github.com:antoniomachine/bigml-ruby.git
  cd bigml
  rake test

Authentication
--------------

All the requests to BigML.io must be authenticated using your username
and `API key <https://bigml.com/account/apikey>`_ and are always
transmitted over HTTPS.

This module will look for your username and API key in the environment
variables ``BIGML_USERNAME`` and ``BIGML_API_KEY`` respectively. You can
add the following lines to your ``.bashrc`` or ``.bash_profile`` to set
those variables automatically when you log in:

.. code-block:: bash

    export BIGML_USERNAME=myusername
    export BIGML_API_KEY=ae579e7e53fb9abd646a6ff8aa99d4afe83ac291

With that environment set up, connecting to BigML is a breeze:

.. code-block:: ruby

    require 'bigml'
    api = BigML::Api.new

Otherwise, you can initialize directly when instantiating the BigML
class as follows:

.. code-block:: ruby

    api = BigML::Api.new('myusername', 'ae579e7e53fb9abd646a6ff8aa99d4afe83ac291')


Quick Start
-----------

Imagine that you want to use `this csv
file <https://static.bigml.com/csv/iris.csv>`_ containing the `Iris
flower dataset <http://en.wikipedia.org/wiki/Iris_flower_data_set>`_ to
predict the species of a flower whose ``sepal length`` is ``5`` and
whose ``sepal width`` is ``2.5``. A preview of the dataset is shown
below. It has 4 numeric fields: ``sepal length``, ``sepal width``,
``petal length``, ``petal width`` and a categorical field: ``species``.
By default, BigML considers the last field in the dataset as the
objective field (i.e., the field that you want to generate predictions
for).

::

    sepal length,sepal width,petal length,petal width,species
    5.1,3.5,1.4,0.2,Iris-setosa
    4.9,3.0,1.4,0.2,Iris-setosa
    4.7,3.2,1.3,0.2,Iris-setosa
    ...
    5.8,2.7,3.9,1.2,Iris-versicolor
    6.0,2.7,5.1,1.6,Iris-versicolor
    5.4,3.0,4.5,1.5,Iris-versicolor
    ...
    6.8,3.0,5.5,2.1,Iris-virginica
    5.7,2.5,5.0,2.0,Iris-virginica
    5.8,2.8,5.1,2.4,Iris-virginica

You can easily generate a prediction following these steps:

.. code-block:: ruby

    require 'bigml'

    api = BigML::Api.new()

    source = api.create_source('./data/iris.csv')
    dataset = api.create_dataset(source)
    model = api.create_model(dataset)
    prediction = api.create_prediction(model, {'sepal length' => 5, 'sepal width' => 2.5})

You can then print the prediction using the ``pprint`` method:

.. code-block:: ruby

    api.pprint(prediction)
    species for {"sepal length"=>5, "sepal width"=>2.5} is Iris-setosa

The ``iris`` dataset has a small number of instances, and usually will be
instantly created, so the ``api.create_`` calls will probably return the
finished resources outright. As BigML's API is asynchronous,
in general you will need to ensure
that objects are finished before using them by using ``api.ok``.

.. code-block:: ruby

    from bigml.api import BigML

    api = BigML::Api.new()

    source = api.create_source('./data/iris.csv')
    api.ok(source)
    dataset = api.create_dataset(source)
    api.ok(dataset)
    model = api.create_model(dataset)
    api.ok(model)
    prediction = api.create_prediction(model, \
        {'petal length': 2.45, 'petal width': 1.75})

This method retrieves the remote object in its latest state and updates
the variable used as argument with this information. Note that the prediction
call is not followed by the ``api.ok`` method. Predictions are so quick to be
generated that, unlike the
rest of resouces, will be generated synchronously as a finished object.


You can also generate an evaluation for the model by using:

.. code-block:: ruby

    test_source = api.create_source('./data/test_iris.csv')
    api.ok(test_source)
    test_dataset = api.create_dataset(test_source)
    api.ok(test_dataset)
    evaluation = api.create_evaluation(model, test_dataset)
    api.ok(evaluation)


Additional Information
----------------------

For additional information about the API, see the
`BigML developer's documentation <https://bigml.com/developers>`_.

Alternative domains
-------------------

The main public domain for the API service is ``bigml.io``, but there are some
alternative domains, either for Virtual Private Cloud setups or
the australian subdomain (``au.bigml.io``). You can change the remote
server domain
to the VPC particular one by either setting the ``BIGML_DOMAIN`` environment
variable to your VPC subdomain:

.. code-block:: bash

    export BIGML_DOMAIN=my_VPC.bigml.io

or setting it when instantiating your connection:

.. code-block:: ruby
                    
    api = BigML::Api.new(username, api_key, false, false, false, nil, 'my_VPC.bigml.io')

The corresponding SSL REST calls will be directed to your private domain
henceforth.

You can also set up your connection to use a particular PredictServer
only for predictions. In order to do so, yo'll need to specify a ``Domain``
object, where you can set up the general domain name as well as the
particular prediction domain name.

.. code-block:: ruby

    domain_info = BigML::Domain.new(domain, prediction_domain, prediction_protocol, 
                                    protocol, verify, prediction_verify)

    api = BigML::Api.new(.....domain_info)

Some arguments for the Domain constructor are more unsual, but they can also
be used to set your special service endpoints:

- protocol (string) Protocol for the service
  (when different from HTTPS)
- verify (boolean) Sets on/off the SSL verification
- prediction_verify (boolean) Sets on/off the SSL verification
  for the prediction server (when different from the general
  SSL verification)
  
  
Fields Structure
----------------

BigML automatically generates idenfiers for each field. To see the
fields and the ids and types that have been assigned to a source you can
use ``get_fields``:

.. code-block:: ruby 

     source = api.get_source(source)
     api.pprint(api.get_fields(source))

     {"000000"=>
         {"column_number"=>0,
          "name"=>"sepal length",
          "optype"=>"numeric",
          "order"=>0},
      "000001"=>
          {"column_number"=>1, 
           "name"=>"sepal width", 
           "optype"=>"numeric", 
           "order"=>1},
      "000002"=>
          {"column_number"=>2,
           "name"=>"petal length",
           "optype"=>"numeric",
           "order"=>2},
      "000003"=>
          {"column_number"=>3, 
           "name"=>"petal width", 
           "optype"=>"numeric", 
           "order"=>3},
      "000004"=>
          {"column_number"=>4,
           "name"=>"species",
           "optype"=>"categorical",
           "order"=>4,
           "term_analysis"=>{"enabled"=>true}}}

When the number of fields becomes very large, it can be useful to exclude or
filter them. This can be done using a query string expression, for instance:

.. code-block:: ruby

    source = api.get_source(source, "limit=10&order_by=name")

would include in the retrieved dictionary the first 10 fields sorted by name.

To handle the field structure you can use the ``Fields`` class. See the
`Fields`_ section.

Dataset
-------

If you want to get some basic statistics for each field you can retrieve
the ``fields`` from the dataset as follows to get a dictionary keyed by
field id:

.. code-block:: ruby

    dataset = api.get_dataset(dataset)
    api.pprint(api.get_fields(dataset))

    {"000000"=>
            {"column_number"=>0,
             "datatype"=>"double",
             "name"=>"sepal length",
             "optype"=>"numeric",
             "order"=>0,
             "preferred"=>true,
             "summary"=>
             {"bins"=>
                     [[4.3, 1],
                      [4.425, 4],
                      [4.6, 4],
                      [4.77143, 7],
                      [4.9625, 16],
                      [5.1, 9],
                      ...
                      [6.3, 9]],
             "kurtosis"=>-0.57357,
             "maximum"=>7.9,
             "mean"=>5.84333,
             "median"=>5.8,
             "minimum"=>4.3,
             "missing_count"=>0,
             "population"=>150,
             "skewness"=>0.31175,
             "splits"=>
                    [4.51526,
                     4.67252,
                     4.81113,
                     4.89582,
                     4.96139,
                     ...
                     7.64746],
             "standard_deviation"=>0.82807,
             "sum"=>876.5,
             "sum_squares"=>5223.85,
             "variance"=>0.68569}},
      "000001"=>
             {"column_number"=>1,
              "datatype"=>"double",
              ...
      "000002"=>
             {"column_number"=>2,
             ...
      "000003"=> ...
      "000004"=>
             {"column_number"=>4,
              "datatype"=>"string",
              "name"=>"species",
              "optype"=>"categorical",
              "order"=>4,
              "preferred"=>true,
              "summary"=>
                  {"categories"=>
                     [["Iris-setosa", 50], ["Iris-versicolor", 50], ["Iris-virginica", 50]],
                      "missing_count"=>0},
              "term_analysis"=>{"enabled"=>true}}}


The field filtering options are also available using a query string expression,
for instance:

.. code-block:: ruby

    dataset = api.get_dataset(dataset, "limit=20")

limits the number of fields that will be included in ``dataset`` to 20.

Model
-----

One of the greatest things about BigML is that the models that it
generates for you are fully white-boxed. To get the explicit tree-like
predictive model for the example above:

.. code-block:: ruby

    model = api.get_model(model)
    api.pprint(model['object']['model']['root'])

    {"children"=>
      [{"children"=>
         [{"children"=>
            [{"confidence"=>0.91033,
              "count"=>39,
              "id"=>3,
              "objective_summary"=>{"categories"=>[["Iris-virginica", 39]]},
              "output"=>"Iris-virginica",
              "predicate"=>{"field"=>"000003", "operator"=>">", "value"=>1.75}},
          {"children"=>
             [{"children"=>
                [{"confidence"=>0.20654,
                  "count"=>1,
                  "id"=>6,
                  "objective_summary"=>{"categories"=>[["Iris-virginica", 1]]},
                  "output"=>"Iris-virginica",
                  "predicate"=>
                   {"field"=>"000002", "operator"=>">", "value"=>5.45}},
                  {"confidence"=>0.34237,
                   "count"=>2,
                   "id"=>7,
                   "objective_summary"=>{"categories"=>[["Iris-versicolor", 2]]},
                   "output"=>"Iris-versicolor",
                   "predicate"=>
                      {"field"=>"000002", "operator"=>"<=", "value"=>5.45}}],
                   "confidence"=>0.20765,
                   "count"=>3,
                   "id"=>5,
                   "objective_summary"=>
                   {"categories"=>[["Iris-versicolor", 2], ["Iris-virginica", 1]]},
                    "output"=>"Iris-versicolor",
                    "predicate"=>{"field"=>"000003", "operator"=>">", "value"=>1.55}},
                    {"confidence"=>0.5101,
                     "count"=>4,
                     "id"=>8,
                     "objective_summary"=>{"categories"=>[["Iris-virginica", 4]]},
                     "output"=>"Iris-virginica",
                     "predicate"=>
                     {"field"=>"000003", "operator"=>"<=", "value"=>1.55}}],
                     "confidence"=>0.35893,
                     "count"=>7,
                     "id"=>4,
                     "objective_summary"=>
       ...

(Note that we have abbreviated the output in the snippet above for
readability: the full predictive model yo'll get is going to contain
much more details).

Again, filtering options are also available using a query string expression,
for instance:

.. code-block:: ruby

    model = api.get_model(model, "limit=5")

limits the number of fields that will be included in ``model`` to 5.


Evaluation
----------

The predictive performance of a model can be measured using many different
measures. In BigML these measures can be obtained by creating evaluations. To
create an evaluation you need the id of the model you are evaluating and the id
of the dataset that contains the data to be tested with. The result is shown
as:

.. code-block:: ruby 

    evaluation = api.get_evaluation(evaluation)
    api.pprint(evaluation['object']['result'])
  
    {"class_names"=>["Iris-setosa", "Iris-versicolor", "Iris-virginica"],
     "mode"=> {"accuracy"=>0.33333,
               "average_f_measure"=>0.16667,
               "average_one_point_auc"=>0.5,
               "average_phi"=>0,
               "average_precision"=>0.11111,
               "average_recall"=>0.33333,
               "confusion_matrix"=>[[50, 0, 0], [50, 0, 0], [50, 0, 0]],
               "per_class_statistics"=> 
                    [{"accuracy"=>0.3333333333333333,
                      "class_name"=>"Iris-setosa",
                      "f_measure"=>0.5,
                      "one_point_auc"=>0.5,
                      "phi_coefficient"=>0,
                      "precision"=>0.3333333333333333,
                      "present_in_test_data"=>true,
                      "recall"=>1.0},
                     {"accuracy"=>0.6666666666666667,
                      "class_name"=>"Iris-versicolor",
                       "f_measure"=>0,
                       "one_point_auc"=>0.5,
                       "phi_coefficient"=>0,
                       "precision"=>0,
                       "present_in_test_data"=>true,
                       "recall"=>0.0},
                     {"accuracy"=>0.6666666666666667,
                       "class_name"=>"Iris-virginica",
                       "f_measure"=>0,
                       "one_point_auc"=>0.5,
                       "phi_coefficient"=>0,
                       "precision"=>0,
                       "present_in_test_data"=>true,
                       "recall"=>0.0}]},
      "model"=> {"accuracy"=>1,
                 "average_f_measure"=>1,
                 "average_one_point_auc"=>1,
                 "average_phi"=>1,
                 "average_precision"=>1,
                 "average_recall"=>1,
                 "confusion_matrix"=>[[50, 0, 0], [0, 50, 0], [0, 0, 50]],
                 "per_class_statistics"=>
                 [{"accuracy"=>1.0,
                   ....
                   "recall"=>1.0}]},
      "random"=> {"accuracy"=>0.32,
                 "average_f_measure"=>0.31823,
                 "average_one_point_auc"=>0.49,
                 "average_phi"=>-0.02088,
                 "average_precision"=>0.31763,
                 "average_recall"=>0.32,
                 "confusion_matrix"=>[[20, 14, 16], [15, 16, 19], [21, 17, 12]],
                 "per_class_statistics"=>
                 [{"accuracy"=>0.56,
                   ....
                   "recall"=>0.24}]}}

where two levels of detail are easily identified. For classifications,
the first level shows these keys:

-  **class_names**: A list with the names of all the categories for the objective field (i.e., all the classes)
-  **mode**: A detailed result object. Measures of the performance of the classifier that predicts the mode class for all the instances in the dataset
-  **model**: A detailed result object.
-  **random**: A detailed result object.  Measures the performance of the classifier that predicts a random class for all the instances in the dataset.

and the detailed result objects include ``accuracy``, ``average_f_measure``, ``average_phi``,
``average_precision``, ``average_recall``, ``confusion_matrix``
and ``per_class_statistics``.

For regressions first level will contain these keys:

-  **mean**: A detailed result object. Measures the performance of the model that predicts the mean for all the instances in the dataset.
-  **model**: A detailed result object.
-  **random**: A detailed result object. Measures the performance of the model that predicts a random class for all the instances in the dataset.

where the detailed result objects include ``mean_absolute_error``,
``mean_squared_error`` and ``r_squared`` (refer to
`developers documentation <https://bigml.com/developers/evaluations>`_ for
more info on the meaning of these measures.

Cluster
-------

For unsupervised learning problems, the cluster is used to classify in a
limited number of groups your training data. The cluster structure is defined
by the centers of each group of data, named centroids, and the data enclosed
in the group. As for in the model's case, the cluster is a white-box resource
and can be retrieved as a JSON:

.. code-block:: ruby

    cluster = api.get_cluster(cluster)
    api.pprint(cluster['object'])

    {   'balance_fields' => true,
        'category' => 0,
        'cluster_datasets' => {   '000000' => '', '000001' => '', '000002' => ''},
        'cluster_datasets_ids' => {   '000000' => '53739b9ae4b0dad82b0a65e6',
                                    '000001' => '53739b9ae4b0dad82b0a65e7',
                                    '000002' => '53739b9ae4b0dad82b0a65e8'},
        'cluster_seed' => '2c249dda00fbf54ab4cdd850532a584f286af5b6',
        'clusters' => {   'clusters' => [   {   'center' => {   '000000' => 58.5,
                                                          '000001' => 26.8314,
                                                          '000002' => 44.27907,
                                                          '000003' => 14.37209},
                                            'count' => 56,
                                            'distance' => {   'bins' => [   [   0.69602,
                                                                            2],
                                                                        [ ... ]
                                                                        [   3.77052,
                                                                            1]],
                                                            'maximum' =>3.77052,
                                                            'mean' => 1.61711,
                                                            'median' => 1.52146,
                                                            'minimum' =>  0.69237,
                                                            'population' => 56,
                                                            'standard_deviation' => 0.6161,
                                                            'sum' => 90.55805,
                                                            'sum_squares' => 167.31926,
                                                            'variance' =>0.37958},
                                            'id' => '000000',
                                            'name' =>  'Cluster 0'},
                                        {   'center' => {   '000000' => 50.06,
                                                          '000001' => 34.28,
                                                          '000002' => 14.62,
                                                          '000003' => 2.46},
                                            'count' => 50,
                                            'distance' => {   'bins' => [   [   0.16917,
                                                                            1],
                                                                        [ ... ]
                                                                        [   4.94699,
                                                                            1]],
                                                            'maximum' => 4.94699,
                                                            'mean' => 1.50725,
                                                            'median' => 1.3393,
                                                            'minimum' => 0.16917,
                                                            'population' => 50,
                                                            'standard_deviation' => 1.00994,
                                                            'sum' => 75.36252,
                                                            'sum_squares' => 163.56918,
                                                            'variance' => 1.01998},
                                            'id' => '000001',
                                            'name' => 'Cluster 1'},
                                        {   'center' => { '000000' => 68.15625,
                                                          '000001' => 31.25781,
                                                          '000002' => 55.48438,
                                                          '000003' => 19.96875},
                                            'count' => 44,
                                            'distance' => {   'bins' => [   [   0.36825,
                                                                            1],
                                                                        [ ... ]
                                                                        [   3.87216,
                                                                            1]],
                                                            'maximum' => 3.87216,
                                                            'mean' => 1.67264,
                                                            'median' => 1.63705,
                                                            'minimum' => 0.36825,
                                                            'population' => 44,
                                                            'standard_deviation' => 0.78905,
                                                            'sum' => 73.59627,
                                                            'sum_squares' => 149.87194,
                                                            'variance' => 0.6226},
                                            'id' => '000002',
                                            'name' => 'Cluster 2'}],
                        'fields' => {   '000000' => { 'column_number' => 0,
                                                    'datatype'  =>'int8',
                                                    'name' => 'sepal length',
                                                    'optype' => 'numeric',
                                                    'order' => 0,
                                                    'preferred' => true,
                                                    'summary' => {   'bins' => [   [   43.75,
                                                                                   4],
                                                                               [ ... ]
                                                                               [   79,
                                                                                   1]],
                                                                   'maximum' => 79,
                                                                   'mean' => 58.43333,
                                                                   'median' => 57.7889,
                                                                   'minimum' => 43,
                                                                   'missing_count' => 0,
                                                                   'population' => 150,
                                                                   'splits' => [   45.15258,
                                                                                 46.72525,
                                                                              72.04226,
                                                                                 76.47461],
                                                                   'standard_deviation' => 8.28066,
                                                                   'sum' => 8765,
                                                                   'sum_squares' => 522385,
                                                                   'variance' => 68.56935}},
                                                                    [ ... ]
                                                                                 [   25,
                                                                                     3]],
                                                                   'maximum' => 25,
                                                                   'mean' => 11.99333,
                                                                   'median' => 13.28483,
                                                                   'minimum' => 1,
                                                                   'missing_count' => 0,
                                                                   'population' => 150,
                                                                   'standard_deviation' => 7.62238,
                                                                   'sum' => 1799,
                                                                   'sum_squares' => 30233,
                                                                   'variance' => 58.10063}}}},
        'code' => 202,
        'columns' => 4,
        'created' => '2014-05-14T16:36:40.993000',
        'credits' => 0.017578125,
        'credits_per_prediction' => 0.0,
        'dataset' => 'dataset/53739b88c8db63122b000411',
        'dataset_field_types' => { 'categorical' => 1,
                                   'datetime' => 0,
                                   'numeric' => 4,
                                   'preferred' => 5,
                                   'text' => 0,
                                   'total' => 5},
        'dataset_status' => true,
        'dataset_type' => 0,
        'description' => '',
        'excluded_fields' => ['000004'],
        'field_scales' => nil,
        'fields_meta' => { 'count' => 4,
                           'limit' => 1000,
                           'offset' => 0,
                           'query_total' => 4,
                           'total' => 4},
        'input_fields' => ['000000', '000001', '000002', '000003'],
        'k' => 3,
        'locale' => 'es-ES',
        'max_columns' => 5,
        'max_rows' => 150,
        'name' => 'my iris',
        'number_of_batchcentroids' => 0,
        'number_of_centroids' => 0,
        'number_of_public_centroids' => 0,
        'out_of_bag' => false,
        'price' => 0.0,
        'private' => true,
        'range' => [1, 150],
        'replacement' => false,
        'resource' => 'cluster/53739b98d994972da7001de8',
        'rows' => 150,
        'sample_rate' => 1.0,
        'scales' => { '000000' => 0.22445382597655375,
                      '000001' => 0.4264213814821549,
                      '000002' => 0.10528680248949522,
                      '000003' => 0.2438379900517961},
        'shared' => false,
        'size' => 4608,
        'source' => 'source/53739b24d994972da7001ddd',
        'source_status' =>  true,
        'status' => { 'code' => 5,
                      'elapsed' => 1009,
                      'message' => 'The cluster has been created',
                      'progress' => 1.0},
        'subscription' => true,
        'tags' => [],
        'updated' => '2014-05-14T16:40:26.234728',
        'white_box' => false}

(Note that we have abbreviated the output in the snippet above for
readability: the full predictive cluster yo'll get is going to contain
much more details).


Anomaly detector
----------------

For anomaly detection problems, BigML anomaly detector uses iforest as an
unsupervised kind of model that detects anomalous data in a dataset. The
information it returns encloses a `top_anomalies` block
that contains a list of the most anomalous
points. For each, we capture a `score` from 0 to 1.  The closer to 1,
the more anomalous. We also capture the `row` which gives values for
each field in the order defined by `input_fields`.  Similarly we give
a list of `importances` which match the `row` values.  These
importances tell us which values contributed most to the anomaly
score. Thus, the structure of an anomaly detector is similar to:

.. code-block:: ruby

    {   'category' => 0,
        'code' => 200,
        'columns' => 14,
        'constraints' => false,
        'created' => '2014-09-08T18:51:11.893000',
        'credits' => 0.11653518676757812,
        'credits_per_prediction' => 0.0,
        'dataset' => 'dataset/540dfa9d9841fa5c88000765',
        'dataset_field_types' => { 'categorical' => 21,
                                   'datetime' => 0,
                                   'numeric' => 21,
                                   'preferred' => 14,
                                   'text' => 0,
                                   'total' =>42},
        'dataset_status' => true,
        'dataset_type' => 0,
        'description' => '',
        'excluded_fields' => [],
        'fields_meta' => { 'count' => 14,
                           'limit' => 1000,
                           'offset' => 0,
                           'query_total' => 14,
                           'total' => 14},
        'forest_size' => 128,
        'input_fields' => [ '000004',
                            '000005',
                            '000009',
                            '000016',
                            '000017',
                            '000018',
                            '000019',
                            '00001e',
                            '00001f',
                            '000020',
                            '000023',
                            '000024',
                            '000025',
                            '000026'],
        'locale' => 'en_US',
        'max_columns' => 42,
        'max_rows' => 200,
        'model' => {   'fields' =>: {   '000004' => {   'column_number' => 4,
                                                 'datatype' => 'int16',
                                                 'name' => 'src_bytes',
                                                 'optype' => 'numeric',
                                                 'order' => 0,
                                                 'preferred' => true,
                                                 'summary' => {   'bins' => [   [   143,
                                                                                2],
                                                                            ...
                                                                            [   370,
                                                                                2]],
                                                                'maximum' => 370,
                                                                'mean' => 248.235,
                                                                'median' => 234.57157,
                                                                'minimum' => 141,
                                                                'missing_count' => 0,
                                                                'population' => 200,
                                                                'splits' => [   159.92462,
                                                                              173.73312,
                                                                              188,
                                                                              ...
                                                                              339.55228],
                                                                'standard_deviation' => 49.39869,
                                                                'sum' => 49647,
                                                                'sum_squares' => 12809729,
                                                                'variance' => 2440.23093}},
                                   '000005' => {   'column_number' => 5,
                                                 'datatype' => 'int32',
                                                 'name' => 'dst_bytes',
                                                 'optype' => 'numeric',
                                                 'order' => 1,
                                                 'preferred' => true,
                                                  ...
                                                                'sum' => 1030851,
                                                                'sum_squares' => 22764504759,
                                                                'variance' => 87694652.45224}},
                                   '000009' => {   'column_number' => 9,
                                                 'datatype' => 'string',
                                                 'name' => 'hot',
                                                 'optype' => 'categorical',
                                                 'order' => 2,
                                                 'preferred' => true,
                                                 'summary' => {   'categories' => [   [   '0',
                                                                                      199],
                                                                                  [   '1',
                                                                                      1]],
                                                                'missing_count' => 0},
                                                 'term_analysis' => {   'enabled' => true}},
                                   '000016' => {   'column_number' => 22,
                                                 'datatype' => 'int8',
                                                 'name' => 'count',
                                                 'optype' => 'numeric',
                                                 'order' => 3,
                                                 'preferred' => true,
                                                                ...
                                                                'population' => 200,
                                                                'standard_deviation' => 5.42421,
                                                                'sum' => 1351,
                                                                'sum_squares' => 14981,
                                                                'variance' => 29.42209}},
                                   '000017' => { ... }}},
                     'kind' => 'iforest',
                     'mean_depthu => 12.314174107142858,
                     'top_anomalies' => [   {   'importance' => [ 0.06768,
                                                                0.01667,
                                                                0.00081,
                                                                0.02437,
                                                                0.04773,
                                                                0.22197,
                                                                0.18208,
                                                                0.01868,
                                                                0.11855,
                                                                0.01983,
                                                                0.01898,
                                                                0.05306,
                                                                0.20398,
                                                                0.00562],
                                              'row' => [ 183.0,
                                                         8654.0,
                                                         '0',
                                                         4.0,
                                                         4.0,
                                                         0.25,
                                                         0.25,
                                                         0.0,
                                                         123.0,
                                                         255.0,
                                                         0.01,
                                                         0.04,
                                                         0.01,
                                                         0.0],
                                              'score' => 0.68782},
                                          {   'importance' => [   0.05645,
                                                                0.02285,
                                                                0.0015,
                                                                0.05196,
                                                                0.04435,
                                                                0.0005,
                                                                0.00056,
                                                                0.18979,
                                                                0.12402,
                                                                0.23671,
                                                                0.20723,
                                                                0.05651,
                                                                0.00144,
                                                                0.00612],
                                              'row' => [   212.0,
                                                         1940.0,
                                                         '0',
                                                         1.0,
                                                         2.0,
                                                         0.0,
                                                         0.0,
                                                         1.0,
                                                         1.0,
                                                         69.0,
                                                         1.0,
                                                         0.04,
                                                         0.0,
                                                         0.0],
                                              'score' => 0.6239},
                                              ...],
                     'trees' => [   {   'root' => {   'children' => [   {   'children' => [   {   'children' => [   {   'children' => [   {   'children =>'
     [   {   'population' => 1,
                                                                                                                                  'predicates' => [   {   'field' => '00001f',
                                                                                                                                                        'op' => '>',
                                                                                                                                                        'value' => 35.54357}]},

    ...
                                                                                                                              {   'population' => 1,
                                                                                                                                  'predicates' => [   {   'field' => '00001f',
                                                                                                                                                        'op' => '<=',
                                                                                                                                                        'value' => 35.54357}]}],
                                                                                                              'population' => 2,
                                                                                                              'predicates' => [   {   'field' => '000005',
                                                                                                                                    'op' => '<=',
                                                                                                                                    'value' => 1385.5166}]}],
                                                                                          'population'=> 3,
                                                                                          'predicates' => [   {   'field' =>'000020',
                                                                                                                'op' => '<=',
                                                                                                                'value' => 65.14308},
                                                                                                            {   'field' => '000019',
                                                                                                                'op' => '=',
                                                                                                                'value' => 0}]}],
                                                                      'population' => 105,
                                                                      'predicates' => [   {   'field' => '000017',
                                                                                            'op' =>  '<=',
                                                                                            'value' => 13.21754},
                                                                                        {   'field' => '000009',
                                                                                            'op' => 'in',
                                                                                            'value' => [   '0']}]}],
                                                  'population' => 126,
                                                  'predicates' => [   true,
                                                                    {   'field' =>  '000018',
                                                                        'op' => '=',
                                                                        'value' => 0}]},
                                      'training_mean_depth' => 11.071428571428571}]},
        'name' => "tiny_kdd's dataset anomaly detector",
        'number_of_batchscores' =>  0,
        'number_of_public_predictions' => 0,
        'number_of_scores' => 0,
        'out_of_bag' => false,
        'price' => 0.0,
        'private' => true,
        'project' => nil,
        'range' => [1, 200],
        'replacement' => false,
        'resource' => 'anomaly/540dfa9f9841fa5c8800076a',
        'rows' => 200,
        'sample_rate' =>: 1.0,
        'sample_size' => 126,
        'seed' => 'BigML',
        'shared' =>  false,
        'size' => 30549,
        'source' => 'source/540dfa979841fa5c7f000363',
        'source_status' => true,
        'status' => {   'code' =>  5,
                      'elapsed' => 32397,
                      'message' => 'The anomaly detector has been created',
                      'progress' => 1.0},
        'subscription' => false,
        'tags' => [],
       'updated' => '2014-09-08T23:54:28.647000',
        'white_box' => false}

Note that we have abbreviated the output in the snippet above for
readability: the full anomaly detector yo'll get is going to contain
much more details).

The `trees` list contains the actual isolation forest, and it can be quite
large usually. That's why, this part of the resource should only be included
in downloads when needed. If you are only interested in other properties, such
as `top_anomalies`, yo'll improve performance by excluding it, using the
`excluded=trees` query string in the API call:

.. code-block:: ruby

    anomaly = api.get_anomaly('anomaly/540dfa9f9841fa5c8800076a', 
                              query_string='excluded=trees')

Each node in an isolation tree can have multiple predicates.
For the node to be a valid branch when evaluated with a data point, all of its
predicates must be true.

Samples
-------

To provide quick access to your row data you can create a ``sample``. Samples
are in-memory objects that can be queried for subsets of data by limiting
their size, the fields or the rows returned. The structure of a sample would
be:

Samples are not permanent objects. Once they are created, they will be
available as long as GETs are requested within periods smaller than
a pre-established TTL (Time to Live). The expiration timer of a sample is
reset every time a new GET is received.

If requested, a sample can also perform linear regression and compute
Pearson's and Spearman's correlations for either one numeric field
against all other numeric fields or between two specific numeric fields.

Correlations
------------

A ``correlation`` resource contains a series of computations that reflect the
degree of dependence between the field set as objective for your predictions
and the rest of fields in your dataset. The dependence degree is obtained by
comparing the distributions in every objective and non-objective field pair,
as independent fields should have probabilistic
independent distributions. Depending on the types of the fields to compare,
the metrics used to compute the correlation degree will be:

- for numeric to numeric pairs:
  `Pearson's <https://en.wikipedia.org/wiki/Pearson_product-moment_correlation_coefficient>`_
  and `Spearman's correlation <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
  coefficients.
- for numeric to categorical pairs:
  `One-way Analysis of Variance <https://en.wikipedia.org/wiki/One-way_analysis_of_variance>`_, with the
  categorical field as the predictor variable.
- for categorical to categorical pairs:
  `contingency table (or two-way table) <https://en.wikipedia.org/wiki/Contingency_table>`,
  `Chi-square test of independence <https://en.wikipedia.org/wiki/Pearson%27s_chi-squared_test>`_
  , and `Cramer's V <https://en.wikipedia.org/wiki/Cram%C3%A9r%27s_V>`_
  and `Tschuprow's T <https://en.wikipedia.org/wiki/Tschuprow%27s_T>`_ coefficients.

An example of the correlation resource JSON structure is:

.. code-block:: ruby

    require 'bigml'
    api = BigML.Api.new
    correlation = api.create_correlation('dataset/55b7a6749841fa2500000d41')
    api.ok(correlation)
    api.pprint(correlation['object'])

    {   'category' => 0,
        'clones' => 0,
        'code' => 200,
        'columns' => 5,
        'correlations' => {   'correlations' => [   {   'name' => 'one_way_anova',
                                                      'result' => {   '000000' => {   'eta_square' => 0.61871,
                                                                                    'f_ratio' => 119.2645,
                                                                                    'p_value' => 0,
                                                                                    'significant' => [   true,
                                                                                                        true,
                                                                                                        true]},
                                                                     '000001' => {   'eta_square' => 0.40078,
                                                                                    'f_ratio' => 49.16004,
                                                                                    'p_value' => 0,
                                                                                    'significant' => [   true,
                                                                                                        true,
                                                                                                        true]},
                                                                     '000002' => {   'eta_square' => 0.94137,
                                                                                    'f_ratio' => 1180.16118,
                                                                                    'p_value' => 0,
                                                                                    'significant' => [   true,
                                                                                                        true,
                                                                                                        true]},
                                                                     '000003' => {   'eta_square' => 0.92888,
                                                                                    'f_ratio' => 960.00715,
                                                                                    'p_value' => 0,
                                                                                    'significant' => [ true,
                                                                                                        true,
                                                                                                        true]}}}],
                             'fields' => {   '000000' => {   'column_number' => 0,
                                                           'datatype' => 'double',
                                                           'idx' => 0,
                                                           'name' => 'sepal length',
                                                           'optype' => 'numeric',
                                                           'order' => 0,
                                                           'preferred' => true,
                                                           'summary' => {   'bins' => [   [   4.3,
                                                                                            1],
                                                                                        [   4.425,
                                                                                            4],
    ...
                                                                                        [   7.9,
                                                                                            1]],
                                                                           'kurtosis' => -0.57357,
                                                                           'maximum' => 7.9,
                                                                           'mean' => 5.84333,
                                                                           'median' => 5.8,
                                                                           'minimum' => 4.3,
                                                                           'missing_count' => 0,
                                                                           'population' => 150,
                                                                           'skewness' => 0.31175,
                                                                           'splits' => [   4.51526,
                                                                                          4.67252,
                                                                                          4.81113,
                                                                                          4.89582,
                                                                                          4.96139,
                                                                                          5.01131,
    ...
                                                                                          6.92597,
                                                                                          7.20423,
                                                                                          7.64746],
                                                                           'standard_deviation' => 0.82807,
                                                                           'sum' => 876.5,
                                                                           'sum_squares' => 5223.85,
                                                                           'variance' => 0.68569}},
                                            '000001' => { 'column_number' => 1,
                                                           'datatype' => 'double',
                                                           'idx' => 1,
                                                           'name' => 'sepal width',
                                                           'optype' => 'numeric',
                                                           'order' => 1,
                                                           'preferred' => true,
                                                           'summary' => {   'counts' => [   [   2,
                                                                                              1],
                                                                                          [   2.2,
    ...
                                            '000004' => { 'column_number' => 4,
                                                           'datatype' => 'string',
                                                           'idx' => 4,
                                                           'name' => 'species',
                                                           'optype' => 'categorical',
                                                           'order' => 4,
                                                           'preferred' => true,
                                                           'summary' >= {   'categories' => [   [   'Iris-setosa',
                                                                                                  50],
                                                                                              [   'Iris-versicolor',
                                                                                                  50],
                                                                                              [   'Iris-virginica',
                                                                                                  50]],
                                                                           'missing_count'=> 0},
                                                           'term_analysis' => {   'enabled' => true}}},
                             'significance_levels' => [0.01, 0.05, 0.1]},
        'created' => '2015-07-28T18:07:37.010000',
        'credits' => 0.017581939697265625,
        'dataset' => 'dataset/55b7a6749841fa2500000d41',
        'dataset_status' => true,
        'dataset_type' => 0,
        'description' => '',
        'excluded_fields' => [],
        'fields_meta'=> {  'count' => 5,
                            'limit' => 1000,
                            'offset' => 0,
                            'query_total' => 5,
                            'total' => 5},
        'input_fields' => ['000000', '000001', '000002', '000003'],
        'locale' => 'en_US',
        'max_columns' => 5,
        'max_rows' => 150,
        'name' => "iris' dataset correlation",
        'objective_field_details' => {   'column_number' => 4,
                                        'datatype' => 'string',
                                        'name' => 'species',
                                        'optype' => 'categorical',
                                        'order' => 4},
        'out_of_bag' => false,
        'price' => 0.0,
        'private' => true,
        'project'=>  nil,
        'range' => [1, 150],
        'replacement' => false,
        'resource' => 'correlation/55b7c4e99841fa24f20009bf',
        'rows' => 150,
        'sample_rate' => 1.0,
        'shared' => false,
        'size' => 4609,
        'source' => 'source/55b7a6729841fa24f100036a',
        'source_status' =>  true,
        'status' => {   'code' => 5,
                       'elapsed' => 274,
                       'message' =>  'The correlation has been created',
                       'progress' => 1.0},
        'subscription' => true,
        'tags' => [],
        'updated' => '2015-07-28T18:07:49.057000',
        'white_box' => false}

Note that the output in the snippet above has been abbreviated. As you see, the
``correlations`` attribute contains the information about each field
correlation to the objective field.

Statistical Tests
-----------------

A ``statisticaltest`` resource contains a series of tests
that compare the
distribution of data in each numeric field of a dataset
to certain canonical distributions,
such as the
`normal distribution <https://en.wikipedia.org/wiki/Normal_distribution>`_
or `Benford's law <https://en.wikipedia.org/wiki/Benford%27s_law>`_
distribution. Statistical test are useful in tasks such as fraud, normality,
or outlier detection.

- Fraud Detection Tests:
Benford: This statistical test performs a comparison of the distribution of
first significant digits (FSDs) of each value of the field to the Benford's
law distribution. Benford's law applies to numerical distributions spanning
several orders of magnitude, such as the values found on financial balance
sheets. It states that the frequency distribution of leading, or first
significant digits (FSD) in such distributions is not uniform.
On the contrary, lower digits like 1 and 2 occur disproportionately
often as leading significant digits. The test compares the distribution
in the field to Bendford's distribution using a Chi-square goodness-of-fit
test, and Cho-Gaines d test. If a field has a dissimilar distribution,
it may contain anomalous or fraudulent values.

- Normality tests:
These tests can be used to confirm the assumption that the data in each field
of a dataset is distributed according to a normal distribution. The results
are relevant because many statistical and machine learning techniques rely on
this assumption.
Anderson-Darling: The Anderson-Darling test computes a test statistic based on
the difference between the observed cumulative distribution function (CDF) to
that of a normal distribution. A significant result indicates that the
assumption of normality is rejected.
Jarque-Bera: The Jarque-Bera test computes a test statistic based on the third
and fourth central moments (skewness and kurtosis) of the data. Again, a
significant result indicates that the normality assumption is rejected.
Z-score: For a given sample size, the maximum deviation from the mean that
would expected in a sampling of a normal distribution can be computed based
on the 68-95-99.7 rule. This test simply reports this expected deviation and
the actual deviation observed in the data, as a sort of sanity check.

- Outlier tests:
Grubbs: When the values of a field are normally distributed, a few values may
still deviate from the mean distribution. The outlier tests reports whether
at least one value in each numeric field differs significantly from the mean
using Grubb's test for outliers. If an outlier is found, then its value will
be returned.

The JSON structure for ``statisticaltest`` resources is similar to this one:

.. code-block:: ruby

    statistical_test = api.create_statistical_test('dataset/55b7a6749841fa2500000d41')
    api.ok(statistical_test)
    api.pprint(statistical_test['object'])

    api.pprint(statistical_test['object'])
    {   'category' => 0,
        'clones' => 0,
        'code' => 200,
        'columns' => 5,
        'created' => '2015-07-28T18:16:40.582000',
        'credits' => 0.017581939697265625,
        'dataset' => 'dataset/55b7a6749841fa2500000d41',
        'dataset_status' => true,
        'dataset_type' => 0,
        'description' => '',
        'excluded_fields' => [],
        'fields_meta' => {   'count' => 5,
                            'limit' => 1000,
                            'offset' => 0,
                            'query_total' => 5,
                            'total' => 5},
        'input_fields' => ['000000', '000001', '000002', '000003'],
        'locale' => 'en_US',
        'max_columns' => 5,
        'max_rows' => 150,
        'name' => u"iris' dataset test",
        'out_of_bag' => false,
        'price' => 0.0,
        'private' => true,
        'project' => nil,
        'range' => [1, 150],
        'replacement' => false,
        'resource' => 'statisticaltest/55b7c7089841fa25000010ad',
        'rows' => 150,
        'sample_rate' => 1.0,
        'shared' => false,
        'size' => 4609,
        'source' => 'source/55b7a6729841fa24f100036a',
        'source_status' => true,
        'status' => {   'code' => 5,
                       'elapsed' => 302,
                       'message' => 'The test has been created',
                       'progress' => 1.0},
        'subscription' => true,
        'tags' => [],
        'statistical_tests' => {   'ad_sample_size' => 1024,
                      'fields' => {   '000000' => {   'column_number' => 0,
                                                    'datatype' => 'double',
                                                    'idx' => 0,
                                                    'name' => 'sepal length',
                                                    'optype' => 'numeric',
                                                    'order' => 0,
                                                    'preferred' => true,
                                                    'summary' => {   'bins' => [   [   4.3,
                                                                                     1],
                                                                                 [   4.425,
                                                                                     4],
    ...
                                                                                 [   7.9,
                                                                                     1]],
                                                                    'kurtosis' => -0.57357,
                                                                    'maximum' => 7.9,
                                                                    'mean' => 5.84333,
                                                                    'median' => 5.8,
                                                                    'minimum' => 4.3,
                                                                    'missing_count' => 0,
                                                                    'population' => 150,
                                                                    'skewness' => 0.31175,
                                                                    'splits' => [   4.51526,
                                                                                   4.67252,
                                                                                   4.81113,
                                                                                   4.89582,
    ...
                                                                                   7.20423,
                                                                                   7.64746],
                                                                    'standard_deviation' => 0.82807,
                                                                    'sum' => 876.5,
                                                                    'sum_squares' => 5223.85,
                                                                    'variance' => 0.68569}},
    ...
                                     '000004' => {   'column_number' => 4,
                                                    'datatype' => 'string',
                                                    'idx' => 4,
                                                    'name' => 'species',
                                                    'optype' => 'categorical',
                                                    'order' => 4,
                                                    'preferred' => true,
                                                    'summary' => {   'categories' => [   [   'Iris-setosa',
                                                                                           50],
                                                                                       [   'Iris-versicolor',
                                                                                           50],
                                                                                       [   'Iris-virginica',
                                                                                           50]],
                                                                    'missing_count' => 0},
                                                    'term_analysis' => {   'enabled' => true}}},
                      'fraud' => [   {   'name' => 'benford',
                                        'result' => {   '000000' => {   'chi_square' => {   'chi_square_value' => 506.39302,
                                                                                         'p_value' => 0,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'cho_gaines' => {   'd_statistic' => 7.124311073683573,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'distribution' => [   0,
                                                                                           0,
                                                                                           0,
                                                                                           22,
                                                                                           61,
                                                                                           54,
                                                                                           13,
                                                                                           0,
                                                                                           0],
                                                                      'negatives' => 0,
                                                                      'zeros' => 0},
                                                       '000001' => {   'chi_square' => {   'chi_square_value' => 396.76556,
                                                                                         'p_value' => 0,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'cho_gaines' => {   'd_statistic' => 7.503503138331123,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'distribution' => [   0,
                                                                                           57,
                                                                                           89,
                                                                                           4,
                                                                                           0,
                                                                                           0,
                                                                                           0,
                                                                                           0,
                                                                                           0],
                                                                      'negatives' => 0,
                                                                      'zeros' => 0},
                                                       '000002' => {   'chi_square' => {   'chi_square_value' => 154.20728,
                                                                                         'p_value' => 0,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'cho_gaines' => {   'd_statistic' => 3.9229974017266054,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'distribution' => [   50,
                                                                                           0,
                                                                                           11,
                                                                                           43,
                                                                                           35,
                                                                                           11,
                                                                                           0,
                                                                                           0,
                                                                                           0],
                                                                      'negatives' => 0,
                                                                      'zeros' => 0},
                                                       '000003' => {   'chi_square' => {   'chi_square_value' => 111.4438,
                                                                                         'p_value' => 0,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'cho_gaines' => {   'd_statistic' => 4.103257341299901,
                                                                                         'significant' => [   true,
                                                                                                             true,
                                                                                                             true]},
                                                                      'distribution' => [   76,
                                                                                           58,
                                                                                           7,
                                                                                           7,
                                                                                           1,
                                                                                           1,
                                                                                           0,
                                                                                           0,
                                                                                           0],
                                                                      'negatives' => 0,
                                                                      'zeros' => 0}}}],
                      'normality' => [   {   'name' => 'anderson_darling',
                                            'result' => {   '000000' => {   'p_value' => 0.02252,
                                                                          'significant' => [   false,
                                                                                              true,
                                                                                              true]},
                                                           '000001' => {   'p_value' => 0.02023,
                                                                          'significant' => [   false,
                                                                                              true,
                                                                                              true]},
                                                           '000002' => {   'p_value' => 0,
                                                                          'significant' => [   true,
                                                                                              true,
                                                                                              true]},
                                                           '000003' => {   'p_value' => 0,
                                                                          'significant' => [   true,
                                                                                              true,
                                                                                              true]}}},
                                        {   'name' => 'jarque_bera',
                                            'result' => {   '000000' => {   'p_value' => 0.10615,
                                                                          'significant' => [   false,
                                                                                              false,
                                                                                              false]},
                                                           '000001' => {   'p_value' => 0.25957,
                                                                          'significant' => [   false,
                                                                                              false,
                                                                                              false]},
                                                           '000002' => {   'p_value' => 0.0009,
                                                                          'significant' => [   true,
                                                                                              true,
                                                                                              true]},
                                                           '000003' => {   'p_value' => 0.00332,
                                                                          'significant' => [   true,
                                                                                              true,
                                                                                              true]}}},
                                        {   'name' => 'z_score',
                                            'result' => {   '000000' => {   'expected_max_z' => 2.71305,
                                                                          'max_z' => 2.48369},
                                                           '000001' => {   'expected_max_z' => 2.71305,
                                                                          'max_z' => 3.08044},
                                                           '000002' => {   'expected_max_z' => 2.71305,
                                                                          'max_z' => 1.77987},
                                                           '000003' => {   'expected_max_z' => 2.71305,
                                                                          'max_z' => 1.70638}}}],
                      'outliers' => [   {   'name' => 'grubbs',
                                           'result' => {   '000000' => {   'p_value' => 1,
                                                                         'significant' => [   false,
                                                                                             false,
                                                                                             false]},
                                                          '000001' => {   'p_value' => 0.26555,
                                                                         'significant' => [   false,
                                                                                             false,
                                                                                             false]},
                                                          '000002' => {   'p_value' => 1,
                                                                         'significant' => [   false,
                                                                                             false,
                                                                                             false]},
                                                          '000003' => {   'p_value' => 1,
                                                                         'significant' => [   false,
                                                                                             false,
                                                                                             false]}}}],
                      'significance_levels' => [0.01, 0.05, 0.1]},
        'updated' => '2015-07-28T18:17:11.829000',
        'white_box' => false}

Note that the output in the snippet above has been abbreviated. As you see, the
``statistical_tests`` attribute contains the ``fraud`, ``normality``
and ``outliers``
sections where the information for each field's distribution is stored.

Logistic Regressions
--------------------

A logistic regression is a supervised machine learning method for
solving classification problems. Each of the classes in the field
you want to predict, the objective field, is assigned a probability depending
on the values of the input fields. The probability is computed
as the value of a logistic function,
whose argument is a linear combination of the predictors' values.
You can create a logistic regression selecting which fields from your
dataset you want to use as input fields (or predictors) and which
categorical field you want to predict, the objective field. Then the
created logistic regression is defined by the set of coefficients in the
linear combination of the values. Categorical
and text fields need some prior work to be modelled using this method. They
are expanded as a set of new fields, one per category or term (respectively)
where the number of occurrences of the category or term is store. Thus,
the linear combination is made on the frequency of the categories or terms.

The JSON structure for a logistic regression is:

.. code-block:: ruby

     api.pprint(logistic_regression['object'])
     {  'balance_objective' =>  false,
        'category' =>  0,
        'code' =>  200,
        'columns' =>  5,
        'created' =>  '2015-10-09T16:11:08.444000',
        'credits' =>  0.017581939697265625,
        'credits_per_prediction' =>  0.0,
        'dataset' =>  'dataset/561304f537203f4c930001ca',
        'dataset_field_types' =>  {   'categorical' =>  1,
                                    'datetime' =>  0,
                                    'effective_fields' =>  5,
                                    'numeric' =>  4,
                                    'preferred' =>  5,
                                    'text' =>  0,
                                    'total' =>  5},
        'dataset_status' =>  true,
        'description' =>  '',
        'excluded_fields' =>  [],
        'fields_meta' =>  {   'count' =>  5,
                            'limit' =>  1000,
                            'offset' =>  0,
                            'query_total' =>  5,
                            'total' =>  5},
        'input_fields' =>  ['000000', '000001', '000002', '000003'],
        'locale' =>  'en_US',
        'logistic_regression' =>  {   'bias' =>  1,
                                    'c' =>  1,
                                    'coefficients' =>  [   [   'Iris-virginica',
                                                             [   -1.7074433493289376,
                                                                 -1.533662474502423,
                                                                 2.47026986670851,
                                                                 2.5567582221085563,
                                                                 -1.2158200612711925]],
                                                         [   'Iris-setosa',
                                                             [   0.41021712519841674,
                                                                 1.464162165246765,
                                                                 -2.26003266131107,
                                                                 -1.0210350909174153,
                                                                 0.26421852991732514]],
                                                         [   'Iris-versicolor',
                                                             [   0.42702327817072505,
                                                                 -1.611817241669904,
                                                                 0.5763832839459982,
                                                                 -1.4069842681625884,
                                                                 1.0946877732663143]]],
                                    'eps' =>  1e-05,
                                    'fields' =>  {   '000000' =>  {   'column_number' =>  0,
                                                                  'datatype' =>  'double',
                                                                  'name' =>  'sepal length',
                                                                  'optype' =>  'numeric', 
                                                                  'order' =>  0,
                                                                  'preferred' =>  true,
                                                                  'summary' =>  {   'bins' =>  [   [   4.3,
                                                                                                   1],
                                                                                               [   4.425,
                                                                                                   4],
                                                                                               [   4.6,
                                                                                                   4],
    ...
                                                                                               [   7.9,
                                                                                                   1]],
                                                                                  'kurtosis' =>  -0.57357,
                                                                                  'maximum' =>  7.9,
                                                                                  'mean' =>  5.84333,
                                                                                  'median' =>  5.8,
                                                                                  'minimum' =>  4.3,
                                                                                  'missing_count' =>  0,
                                                                                  'population' =>  150,
                                                                                  'skewness' =>  0.31175,
                                                                                  'splits' =>  [   4.51526,
                                                                                                 4.67252,
                                                                                                 4.81113,
    ...
                                                                                                 6.92597,
                                                                                                 7.20423,
                                                                                                 7.64746],
                                                                                  'standard_deviation' =>  0.82807,
                                                                                  'sum' =>  876.5,
                                                                                  'sum_squares' =>  5223.85,
                                                                                  'variance' =>  0.68569}},
                                                   '000001' =>  {   'column_number' =>  1,
                                                                  'datatype' =>  'double',
                                                                  'name' =>  'sepal width',
                                                                  'optype' =>  'numeric',
                                                                  'order' =>  1,
                                                                  'preferred' =>  true,
                                                                  'summary' =>  {   'counts' =>  [   [   2,
                                                                                                     1],
                                                                                                 [   2.2,
                                                                                                     3],
    ...
                                                                                                 [   4.2,
                                                                                                     1],
                                                                                                 [   4.4,
                                                                                                     1]],
                                                                                  'kurtosis' =>  0.18098,
                                                                                  'maximum' =>  4.4,
                                                                                  'mean' =>  3.05733,
                                                                                  'median' =>  3,
                                                                                  'minimum' =>  2,
                                                                                  'missing_count' =>  0,
                                                                                  'population' =>  150,
                                                                                  'skewness' =>  0.31577,
                                                                                  'standard_deviation' =>  0.43587,
                                                                                  'sum' =>  458.6,
                                                                                  'sum_squares' =>  1430.4,
                                                                                  'variance' =>  0.18998}},
                                                   '000002' =>  {   'column_number' =>  2,
                                                                  'datatype' =>  'double',
                                                                  'name' =>  'petal length',
                                                                  'optype' =>  'numeric',
                                                                  'order' =>  2,
                                                                  'preferred' =>  true,
                                                                  'summary' =>  {   'bins' =>  [   [   1,
                                                                                                   1],
                                                                                               [   1.16667,
                                                                                                   3],
    ...
                                                                                               [   6.6,
                                                                                                   1],
                                                                                               [   6.7,
                                                                                                   2],
                                                                                               [   6.9,
                                                                                                   1]],
                                                                                  'kurtosis' =>  -1.39554,
                                                                                  'maximum' =>  6.9,
                                                                                  'mean' =>  3.758,
                                                                                  'median' =>  4.35,
                                                                                  'minimum' =>  1,
                                                                                  'missing_count' =>  0,
                                                                                  'population' =>  150,
                                                                                  'skewness' =>  -0.27213,
                                                                                  'splits' =>  [   1.25138,
                                                                                                 1.32426,
                                                                                                 1.37171,
    ...
                                                                                                 6.02913,
                                                                                                 6.38125],
                                                                                  'standard_deviation' =>  1.7653,
                                                                                  'sum' =>  563.7,
                                                                                  'sum_squares' =>  2582.71,
                                                                                  'variance' =>  3.11628}},
                                                   '000003' =>  {   'column_number' =>  3,
                                                                  'datatype' =>  'double',
                                                                  'name' =>  'petal width',
                                                                  'optype' =>  'numeric',
                                                                  'order' =>  3,
                                                                  'preferred' =>  true,
                                                                  'summary' =>  {   'counts' =>  [   [   0.1,
                                                                                                     5],
                                                                                                 [   0.2,
                                                                                                     29],
    ...
                                                                                                 [   2.4,
                                                                                                     3],
                                                                                                 [   2.5,
                                                                                                     3]],
                                                                                  'kurtosis' =>  -1.33607,
                                                                                  'maximum' =>  2.5,
                                                                                  'mean' =>  1.19933,
                                                                                  'median' =>  1.3,
                                                                                  'minimum' =>  0.1,
                                                                                  'missing_count' =>  0,
                                                                                  'population' =>  150,
                                                                                  'skewness' =>  -0.10193,
                                                                                  'standard_deviation' =>  0.76224,
                                                                                  'sum' =>  179.9,
                                                                                  'sum_squares' =>  302.33,
                                                                                  'variance' =>  0.58101}},
                                                   '000004' =>  {   'column_number' =>  4,
                                                                  'datatype' =>  'string',
                                                                  'name' =>  'species',
                                                                  'optype' =>  'categorical',
                                                                  'order' =>  4,
                                                                  'preferred' =>  true,
                                                                  'summary' =>  {   'categories' =>  [   [   'Iris-setosa',
                                                                                                         50],
                                                                                                     [   'Iris-versicolor',
                                                                                                         50],
                                                                                                     [   'Iris-virginica',
                                                                                                         50]],
                                                                                  'missing_count' =>  0},
                                                                  'term_analysis' =>  {   'enabled' =>  true}}},
                                    'normalize' =>  false,
                                    'regularization' =>  'l2'},
        'max_columns' =>  5,
        'max_rows' =>  150,
        'name' =>  u"iris' dataset's logistic regression",
        'number_of_batchpredictions' =>  0,
        'number_of_evaluations' =>  0,
        'number_of_predictions' =>  1,
        'objective_field' =>  '000004',
        'objective_field_name' =>  'species',
        'objective_field_type' =>  'categorical',
        'objective_fields' =>  ['000004'],
        'out_of_bag' =>  false,
        'private' =>  true,
        'project' =>  'project/561304c137203f4c9300016c',
        'range' =>  [1, 150],
        'replacement' =>  false,
        'resource' =>  'logisticregression/5617e71c37203f506a000001',
        'rows' =>  150,
        'sample_rate' =>  1.0,
        'shared' =>  false,
        'size' =>  4609,
        'source' =>  'source/561304f437203f4c930001c3',
        'source_status' =>  true,
        'status' =>  {   'code' =>  5,
                       'elapsed' =>  86,
                       'message' =>  'The logistic regression has been created',
                       'progress' =>  1.0},
        'subscription' =>  false,
        'tags' =>  ['species'],
        'updated' =>  '2015-10-09T16:14:02.336000',
        'white_box' =>  false}

Note that the output in the snippet above has been abbreviated. As you see,
the ``logistic_regression`` attribute stores the coefficients used in the
logistic function as well as the configuration parameters described in
the `developers section <https://bigml.com/developers/logisticregressions>`_ .


Associations
------------

Association Discovery is a popular method to find out relations among values
in high-dimensional datasets.

A common case where association discovery is often used is
market basket analysis. This analysis seeks for customer shopping
patterns across large transactional
datasets. For instance, do customers who buy hamburgers and ketchup also
consume bread?

Businesses use those insights to make decisions on promotions and product
placements.
Association Discovery can also be used for other purposes such as early
incident detection, web usage analysis, or software intrusion detection.

In BigML, the Association resource object can be built from any dataset, and
its results are a list of association rules between the items in the dataset.
In the example case, the corresponding
association rule would have hamburguers and ketchup as the items at the
left hand side of the association rule and bread would be the item at the
right hand side. Both sides in this association rule are related,
in the sense that observing
the items in the left hand side implies observing the items in the right hand
side. There are some metrics to ponder the quality of these association rules:

- Support: the proportion of instances which contain an itemset.

For an association rule, it means the number of instances in the dataset which
contain the rule's antecedent and rule's consequent together
over the total number of instances (N) in the dataset.

It gives a measure of the importance of the rule. Association rules have
to satisfy a minimum support constraint (i.e., min_support).

- Coverage: the support of the antedecent of an association rule.
It measures how often a rule can be applied.

- Confidence or (strength): The probability of seeing the rule's consequent
under the condition that the instances also contain the rule's antecedent.
Confidence is computed using the support of the association rule over the
coverage. That is, the percentage of instances which contain the consequent
and antecedent together over the number of instances which only contain
the antecedent.

Confidence is directed and gives different values for the association
rules Antecedent → Consequent and Consequent → Antecedent. Association
rules also need to satisfy a minimum confidence constraint
(i.e., min_confidence).

- Leverage: the difference of the support of the association
rule (i.e., the antecedent and consequent appearing together) and what would
be expected if antecedent and consequent where statistically independent.
This is a value between -1 and 1. A positive value suggests a positive
relationship and a negative value suggests a negative relationship.
0 indicates independence.

Lift: how many times more often antecedent and consequent occur together
than expected if they where statistically independent.
A value of 1 suggests that there is no relationship between the antecedent
and the consequent. Higher values suggest stronger positive relationships.
Lower values suggest stronger negative relationships (the presence of the
antecedent reduces the likelihood of the consequent)

As to the items used in association rules, each type of field is parsed to
extract items for the rules as follows:

- Categorical: each different value (class) will be considered a separate item.
- Text: each unique term will be considered a separate item.
- Items: each different item in the items summary will be considered.
- Numeric: Values will be converted into categorical by making a
segmentation of the values.
For example, a numeric field with values ranging from 0 to 600 split
into 3 segments:
segment 1 → [0, 200), segment 2 → [200, 400), segment 3 → [400, 600].
You can refine the behavior of the transformation using
`discretization <https://bigml.com/developers/associations#ad_create_discretization>`_
and `field_discretizations <https://bigml.com/developers/associations#ad_create_field_discretizations>`_.

The JSON structure for an association resource is:

.. code-block:: ruby

    api.pprint(association['object'])
    {
        "associations" => {
            "complement" => false,
            "discretization" => {
                "pretty" => true,
                "size" => 5,
                "trim" => 0,
                "type" => "width"
            },
            "items" => [
                {
                    "complement" => false,
                    "count" => 32,
                    "field_id" => "000000",
                    "name" => "Segment 1",
                    "bin_end" => 5,
                    "bin_start" => null
                },
                {
                    "complement" => false,
                    "count" => 49,
                    "field_id" => "000000",
                    "name" => "Segment 3",
                    "bin_end" => 7,
                    "bin_start" => 6
                },
                {
                    "complement" => false,
                    "count" => 12,
                    "field_id" => "000000",
                    "name" => "Segment 4",
                    "bin_end" => null,
                    "bin_start" => 7
                },
                {
                    "complement" => false,
                    "count" => 19,
                    "field_id" => "000001",
                    "name" => "Segment 1",
                    "bin_end" => 2.5,
                    "bin_start" => null
                },
                ...
                {
                    "complement" => false,
                    "count" => 50,
                    "field_id" => "000004",
                    "name" => "Iris-versicolor"
                },
               {
                    "complement" => false,
                    "count" => 50,
                    "field_id" => "000004",
                    "name" => "Iris-virginica"
                }
            ],
            "max_k" =>  100,
            "min_confidence" => 0,
            "min_leverage" => 0,
            "min_lift" => 1,
            "min_support" => 0,
            "rules" => [
                {
                    "confidence" => 1,
                    "id" => "000000",
                    "leverage" => 0.22222,
                    "lhs" => [
                        13
                    ],
                    "lhs_cover" => [
                        0.33333,
                        50
                    ],
                    "lift" => 3,
                    "p_value" => 0.000000000,
                    "rhs" => [
                        6
                    ],
                    "rhs_cover" => [
                        0.33333,
                        50
                    ],
                    "support" => [
                        0.33333,
                        50
                    ]
                },
                {
                    "confidence" => 1,
                    "id" => "000001",
                    "leverage" => 0.22222,
                    "lhs" => [
                        6
                    ],
                    "lhs_cover" => [
                        0.33333,
                        50
                    ],
                    "lift" => 3,
                    "p_value" => 0.000000000,
                    "rhs" => [
                        13
                    ],
                    "rhs_cover" => [
                        0.33333,
                        50
                    ],
                    "support" => [
                        0.33333,
                        50
                    ]
                },
                ...
                {
                    "confidence" => 0.26,
                    "id" => "000029",
                    "leverage" => 0.05111,
                    "lhs" => [
                        13
                    ],
                    "lhs_cover" => [
                        0.33333,
                        50
                    ],
                    "lift" => 2.4375,
                    "p_value" => 0.0000454342,
                    "rhs" => [
                        5
                    ],
                    "rhs_cover" => [
                        0.10667,
                        16
                    ],
                    "support" => [
                        0.08667,
                        13
                    ]
                },
                {
                    "confidence" => 0.18,
                    "id" => "00002a",
                    "leverage" => 0.04,
                    "lhs" => [
                        15
                    ],
                    "lhs_cover" => [
                        0.33333,
                        50
                    ],
                    "lift" => 3,
                    "p_value" => 0.0000302052,
                    "rhs" => [
                        9
                    ],
                    "rhs_cover" => [
                        0.06,
                        9
                    ],
                    "support" => [
                        0.06,
                        9
                    ]
                },
                {
                    "confidence" => 1,
                    "id" => "00002b",
                    "leverage" => 0.04,
                    "lhs" => [
                        9
                    ],
                    "lhs_cover" => [
                        0.06,
                        9
                    ],
                    "lift" => 3,
                    "p_value" => 0.0000302052,
                    "rhs" => [
                        15
                    ],
                    "rhs_cover" => [
                        0.33333,
                        50
                    ],
                    "support" => [
                        0.06,
                        9
                    ]
                }
            ],
            "rules_summary" => {
                "confidence" => {
                    "counts" => [
                        [
                            0.18,
                            1
                        ],
                        [
                            0.24,
                            1
                        ],
                        [
                            0.26,
                            2
                        ],
                        ...
                        [
                            0.97959,
                            1
                        ],
                        [
                            1,
                            9
                        ]
                    ],
                    "maximum" => 1,
                    "mean" => 0.70986,
                    "median" => 0.72864,
                    "minimum" => 0.18,
                    "population" => 44,
                    "standard_deviation" => 0.24324,
                    "sum" => 31.23367,
                    "sum_squares" => 24.71548,
                    "variance" => 0.05916
                },
                "k" => 44,
                "leverage" => {
                    "counts" => [
                        [
                            0.04,
                            2
                        ],
                        [
                            0.05111,
                            4
                        ],
                        [
                            0.05316,
                            2
                        ],
                        ...
                        [
                            0.22222,
                            2
                        ]
                    ],
                    "maximum" => 0.22222,
                    "mean" => 0.10603,
                    "median" => 0.10156,
                    "minimum" => 0.04,
                    "population" => 44,
                    "standard_deviation" => 0.0536,
                    "sum" => 4.6651,
                    "sum_squares" => 0.61815,
                    "variance" => 0.00287
                },
                "lhs_cover" => {
                    "counts" => [
                        [
                            0.06,
                            2
                        ],
                        [
                            0.08,
                            2
                        ],
                        [
                            0.10667,
                            4
                        ],
                        [
                            0.12667,
                            1
                        ],
                        ...
                        [
                            0.5,
                            4
                        ]
                    ],
                    "maximum" => 0.5,
                    "mean" => 0.29894,
                    "median" => 0.33213,
                    "minimum" => 0.06,
                    "population" => 44,
                    "standard_deviation" => 0.13386,
                    "sum" => 13.15331,
                    "sum_squares" => 4.70252,
                    "variance" => 0.01792
                },
                "lift" => {
                    "counts" => [
                        [
                            1.40625,
                            2
                        ],
                        [
                            1.5067,
                            2
                        ],
                        ...
                        [
                            2.63158,
                            4
                        ],
                        [
                            3,
                            10
                        ],
                        [
                            4.93421,
                            2
                        ],
                        [
                            12.5,
                            2
                        ]
                    ],
                    "maximum" => 12.5,
                    "mean" => 2.91963,
                    "median" => 2.58068,
                    "minimum" => 1.40625,
                    "population" => 44,
                    "standard_deviation" => 2.24641,
                    "sum" => 128.46352,
                    "sum_squares" => 592.05855,
                    "variance" => 5.04635
                },
                "p_value" => {
                    "counts" => [
                        [
                            0.000000000,
                            2
                        ],
                        [
                            0.000000000,
                            4
                        ],
                        [
                            0.000000000,
                            2
                        ],
                        ...
                        [
                            0.0000910873,
                            2
                        ]
                    ],
                    "maximum" => 0.0000910873,
                    "mean" => 0.0000106114,
                    "median" => 0.00000000,
                    "minimum" => 0.000000000,
                    "population" => 44,
                    "standard_deviation" => 0.0000227364,
                    "sum" => 0.000466903,
                    "sum_squares" => 0.0000000,
                    "variance" => 0.000000001
                },
                "rhs_cover" => {
                    "counts" => [
                        [
                            0.06,
                            2
                        ],
                        [
                            0.08,
                            2
                        ],
                        ...
                        [
                            0.42667,
                            2
                        ],
                        [
                            0.46667,
                            3
                        ],
                        [
                            0.5,
                            4
                        ]
                    ],
                    "maximum" => 0.5,
                    "mean" => 0.29894,
                    "median" => 0.33213,
                    "minimum" => 0.06,
                    "population" => 44,
                    "standard_deviation" => 0.13386,
                    "sum" => 13.15331,
                    "sum_squares" => 4.70252,
                    "variance" => 0.01792
                },
                "support" => {
                    "counts" => [
                        [
                            0.06,
                            4
                        ],
                        [
                            0.06667,
                            2
                        ],
                        [
                            0.08,
                            2
                        ],
                        [
                            0.08667,
                            4
                        ],
                        [
                            0.10667,
                            4
                        ],
                        [
                            0.15333,
                            2
                        ],
                        [
                            0.18667,
                            4
                        ],
                        [
                            0.19333,
                            2
                        ],
                        [
                            0.20667,
                            2
                        ],
                        [
                            0.27333,
                            2
                        ],
                        [
                            0.28667,
                            2
                        ],
                        [
                            0.3,
                            4
                        ],
                        [
                            0.32,
                            2
                        ],
                        [
                            0.33333,
                            6
                        ],
                        [
                            0.37333,
                            2
                        ]
                    ],
                    "maximum" => 0.37333,
                    "mean" => 0.20152,
                    "median" => 0.19057,
                    "minimum" => 0.06,
                    "population" => 44,
                    "standard_deviation" => 0.10734,
                    "sum" => 8.86668,
                    "sum_squares" => 2.28221,
                    "variance" => 0.01152
                }
            },
            "search_strategy" => "leverage",
            "significance_level" => 0.05
        },
        "category" => 0,
        "clones" => 0,
        "code" => 200,
        "columns" => 5,
        "created" => "2015-11-05T08:06:08.184000",
        "credits" => 0.017581939697265625,
        "dataset" => "dataset/562fae3f4e1727141d00004e",
        "dataset_status" => true,
        "dataset_type" => 0,
        "description" => "",
        "excluded_fields" => [ ],
        "fields_meta" => {
            "count" => 5,
            "limit" => 1000,
            "offset" => 0,
            "query_total" => 5,
            "total" => 5
        },
        "input_fields" => [
            "000000",
            "000001",
            "000002",
            "000003",
            "000004"
        ],
        "locale" => "en_US",
        "max_columns" => 5,
        "max_rows" => 150,
        "name" => "iris' dataset's association",
        "out_of_bag" => false,
        "price" => 0,
        "private" => true,
        "project" => null,
        "range" => [
            1,
            150
        ],
        "replacement" => false,
        "resource" => "association/5621b70910cb86ae4c000000",
        "rows" => 150,
        "sample_rate" => 1,
        "shared" => false,
        "size" => 4609,
        "source" => "source/562fae3a4e1727141d000048",
        "source_status" => true,
        "status" => {
            "code" => 5,
            "elapsed" => 1072,
            "message" => "The association has been created",
            "progress" => 1
        },
        "subscription" => false,
        "tags" => [ ],
        "updated" => "2015-11-05T08:06:20.403000",
        "white_box" => false
    }

Note that the output in the snippet above has been abbreviated. As you see,
the ``associations`` attribute stores items, rules and metrics extracted
from the datasets as well as the configuration parameters described in
the `developers section <https://bigml.com/developers/associations>`_ .


Topic Models
------------

A topic model is an unsupervised machine learning method
for unveiling all the different topics
underlying a collection of documents.
BigML uses Latent Dirichlet Allocation (LDA), one of the most popular
probabilistic methods for topic modeling.
In BigML, each instance (i.e. each row in your dataset) will
be considered a document and the contents of all the text fields
given as inputs will be automatically concatenated and considered the
document bag of words.

Topic model is based on the assumption that any document
exhibits a mixture of topics. Each topic is composed of a set of words
which are thematically related. The words from a given topic have different
probabilities for that topic. At the same time, each word can be attributable
to one or several topics. So for example the word "sea" may be found in
a topic related with sea transport but also in a topic related to holidays.
Topic model automatically discards stop words and high
frequency words.

Topic model's main applications include browsing, organizing and understanding
large archives of documents. It can been applied for information retrieval,
collaborative filtering, assessing document similarity among others.
The topics found in the dataset can also be very useful new features
before applying other models like classification, clustering, or
anomaly detection.

The JSON structure for a topic model is:

.. code-block:: ruby

    >>> api.pprint(topic['object'])
    {   'category' =>  0,
        'code' =>  200,
        'columns' =>  1,
        'configuration' =>  None,
        'configuration_status' =>  false,
        'created' =>  '2016-11-23T23 => 47 => 54.703000',
        'credits' =>  0.0,
        'credits_per_prediction' =>  0.0,
        'dataset' =>  'dataset/58362aa0983efc45a0000005',
        'dataset_field_types' =>  {   'categorical' =>  1,
                                    'datetime' =>  0,
                                    'effective_fields' =>  672,
                                    'items' =>  0,
                                    'numeric' =>  0,
                                    'preferred' =>  2,
                                    'text' =>  1,
                                    'total' =>  2},
        'dataset_status' =>  true,
        'dataset_type' =>  0,
        'description' =>  '',
        'excluded_fields' =>  [],
        'fields_meta' =>  {   'count' =>  1,
                            'limit' =>  1000,
                            'offset' =>  0,
                            'query_total' =>  1,
                            'total' =>  1},
        'input_fields' =>  ['000001'],
        'locale' =>  'en_US',
        'max_columns' =>  2,
        'max_rows' =>  656,
        'name' =>  u"spam dataset's Topic Model ",
        'number_of_batchtopicdistributions' =>  0,
        'number_of_public_topicdistributions' =>  0,
        'number_of_topicdistributions' =>  0,
        'ordering' =>  0,
        'out_of_bag' =>  false,
        'price' =>  0.0,
        'private' =>  true,
        'project' =>  None,
        'range' =>  [1, 656],
        'replacement' =>  false,
        'resource' =>  'topicmodel/58362aaa983efc45a1000007',
        'rows' =>  656,
        'sample_rate' =>  1.0,
        'shared' =>  false,
        'size' =>  54740,
        'source' =>  'source/58362a69983efc459f000001',
        'source_status' =>  true,
        'status' =>  {   'code' =>  5,
                       'elapsed' =>  3222,
                       'message' =>  'The topic model has been created',
                       'progress' =>  1.0},
        'subscription' =>  true,
        'tags' =>  [],
        'topic_model' =>  {   'alpha' =>  4.166666666666667,
                            'beta' =>  0.1,
                            'bigrams' =>  false,
                            'case_sensitive' =>  false,
                            'fields' =>  {   '000001' =>  {   'column_number' =>  1,
                                                          'datatype' =>  'string',
                                                          'name' =>  'Message',
                                                          'optype' =>  'text',
                                                          'order' =>  0,
                                                          'preferred' =>  true,
                                                          'summary' =>  {   'average_length' =>  78.14787,
                                                                          'missing_count' =>  0,
                                                                          'tag_cloud' =>  [   [   'call',
                                                                                                72],
                                                                                            [   'ok',
                                                                                                36],
                                                                                            [   'gt',
                                                                                                34],
    ...
                                                                                            [   'worse',
                                                                                                2],
                                                                                            [   'worth',
                                                                                                2],
                                                                                            [   'write',
                                                                                                2],
                                                                                            [   'yest',
                                                                                                2],
                                                                                            [   'yijue',
                                                                                                2]],
                                                                          'term_forms' =>  {   }},
                                                          'term_analysis' =>  {   'case_sensitive' =>  false,
                                                                                'enabled' =>  true,
                                                                                'language' =>  'en',
                                                                                'stem_words' =>  false,
                                                                                'token_mode' =>  'all',
                                                                                'use_stopwords' =>  false}}},
                            'hashed_seed' =>  62146850,
                            'language' =>  'en',
                            'number_of_topics' =>  12,
                            'term_limit' =>  4096,
                            'term_topic_assignments' =>  [   [   0,
                                                               5,
                                                               0,
                                                               1,
                                                               0,
                                                               19,
                                                               0,
                                                               0,
                                                               19,
                                                               0,
                                                               1,
                                                               0],
                                                           [   0,
                                                               0,
                                                               0,
                                                               13,
                                                               0,
                                                               0,
                                                               0,
                                                               0,
                                                               5,
                                                               0,
                                                               0,
                                                               0],
    ...
                                                           [   0,
                                                               7,
                                                               27,
                                                               0,
                                                               112,
                                                               0,
                                                               0,
                                                               0,
                                                               0,
                                                               0,
                                                               14,
                                                               2]],
                            'termset' =>  [   '000',
                                            '03',
                                            '04',
                                            '06',
                                            '08000839402',
                                            '08712460324',
    ...

                                            'yes',
                                            'yest',
                                            'yesterday',
                                            'yijue',
                                            'yo',
                                            'yr',
                                            'yup',
                                            '\xfc'],
                            'top_n_terms' =>  10,
                            'topicmodel_seed' =>  '26c386d781963ca1ea5c90dab8a6b023b5e1d180',
                            'topics' =>  [   {   'id' =>  '000000',
                                               'name' =>  'Topic 00',
                                               'probability' =>  0.09375,
                                               'top_terms' =>  [   [   'im',
                                                                     0.04849],
                                                                 [   'hi',
                                                                     0.04717],
                                                                 [   'love',
                                                                     0.04585],
                                                                 [   'please',
                                                                     0.02867],
                                                                 [   'tomorrow',
                                                                     0.02867],
                                                                 [   'cos',
                                                                     0.02823],
                                                                 [   'sent',
                                                                     0.02647],
                                                                 [   'da',
                                                                     0.02383],
                                                                 [   'meet',
                                                                     0.02207],
                                                                 [   'dinner',
                                                                     0.01898]]},
                                           {   'id' =>  '000001',
                                               'name' =>  'Topic 01',
                                               'probability' =>  0.08215,
                                               'top_terms' =>  [   [   'lt',
                                                                     0.1015],
                                                                 [   'gt',
                                                                     0.1007],
                                                                 [   'wish',
                                                                     0.03958],
                                                                 [   'feel',
                                                                     0.0272],
                                                                 [   'shit',
                                                                     0.02361],
                                                                 [   'waiting',
                                                                     0.02281],
                                                                 [   'stuff',
                                                                     0.02001],
                                                                 [   'name',
                                                                     0.01921],
                                                                 [   'comp',
                                                                     0.01522],
                                                                 [   'forgot',
                                                                     0.01482]]},
    ...
                                           {   'id' =>  '00000b',
                                               'name' =>  'Topic 11',
                                               'probability' =>  0.0826,
                                               'top_terms' =>  [   [   'call',
                                                                     0.15084],
                                                                 [   'min',
                                                                     0.05003],
                                                                 [   'msg',
                                                                     0.03185],
                                                                 [   'home',
                                                                     0.02648],
                                                                 [   'mind',
                                                                     0.02152],
                                                                 [   'lt',
                                                                     0.01987],
                                                                 [   'bring',
                                                                     0.01946],
                                                                 [   'camera',
                                                                     0.01905],
                                                                 [   'set',
                                                                     0.01905],
                                                                 [   'contact',
                                                                     0.01781]]}],
                            'use_stopwords' =>  false},
        'updated' =>  '2016-11-23T23 => 48 => 03.336000',
        'white_box' =>  false}

Note that the output in the snippet above has been abbreviated.


The topic model returns a list of top terms for each topic found in the data.
Note that topics are not labeled, so you have to infer their meaning according
to the words they are composed of.

Once you build the topic model you can calculate each topic probability
for a given document by using Topic Distribution.
This information can be useful to find documents similarities based
on their thematic.

As you see,
the ``topic_model`` attribute stores the topics and termset and term to
topic assignment,
as well as the configuration parameters described in
the `developers section <https://bigml.com/api/topicmodels>`_ .


Time Series
-----------

A time series model is a supervised learning method to forecast the future
values of a field based on its previously observed values.
It is used to analyze time based data when historical patterns can explain
the future behavior such as stock prices, sales forecasting,
website traffic, production and inventory analysis, weather forecasting, etc.
A time series model needs to be trained with time series data,
i.e., a field containing a sequence of equally distributed data points in time.

BigML implements exponential smoothing to train time series models.
Time series data is modeled as a level component and it can optionally
include a trend (damped or not damped) and a seasonality
components. You can learn more about how to include these components and their
use in the `API documentation page <https://bigml.io/api/>`_.

You can create a time series model selecting one or several fields from
your dataset, that will be the ojective fields. The forecast will compute
their future values.


The JSON structure for a time series is:

.. code-block:: ruby

    >>> api.pprint(time_series['object'])
    {   'category'=> 0,
        'clones'=> 0,
        'code'=> 200,
        'columns'=> 1,
        'configuration'=> None,
        'configuration_status'=> false,
        'created'=> '2017-07-15T12=>49=>42.601000',
        'credits'=> 0.0,
        'dataset'=> 'dataset/5968ec42983efc21b0000016',
        'dataset_field_types'=> {   'categorical'=> 0,
                                    'datetime'=> 0,
                                    'effective_fields'=> 6,
                                    'items'=> 0,
                                    'numeric'=> 6,
                                    'preferred'=> 6,
                                    'text'=> 0,
                                    'total'=> 6},
        'dataset_status'=> true,
        'dataset_type'=> 0,
        'description'=> '',
        'fields_meta'=> {   'count'=> 1,
                            'limit'=> 1000,
                            'offset'=> 0,
                            'query_total'=> 1,
                            'total'=> 1},
        'forecast'=> {   '000005'=> [   {   'lower_bound'=> [   30.14111,
                                                                30.14111,
                                                                ...
                                                                30.14111],
                                            'model'=> 'A,N,N',
                                            'point_forecast'=> [   68.53181,
                                                                   68.53181,
                                                                   ...
                                                                   68.53181,
                                                                   68.53181],
                                            'time_range'=> {   'end'=> 129,
                                                               'interval'=> 1,
                                                               'interval_unit'=> 'milliseconds',
                                                               'start'=> 80},
                                            'upper_bound'=> [   106.92251,
                                                                106.92251,
                                                                ...
                                                                106.92251,
                                                                106.92251]},
                                        {   'lower_bound'=> [   35.44118,
                                                                35.5032,
                                                                ...
                                                                35.28083],
                                            'model'=> 'A,Ad,N',
                            ...
                                                                   66.83537,
                                                                   66.9465],
                                            'time_range'=> {   'end'=> 129,
                                                               'interval'=> 1,
                                                               'interval_unit'=> 'milliseconds',
                                                               'start'=> 80}}]},
        'horizon'=> 50,
        'locale'=> 'en_US',
        'max_columns'=> 6,
        'max_rows'=> 80,
        'name'=> 'my_ts_data',
        'name_options'=> 'period=1, range=[1, 80]',
        'number_of_evaluations'=> 0,
        'number_of_forecasts'=> 0,
        'number_of_public_forecasts'=> 0,
        'objective_field'=> '000005',
        'objective_field_name'=> 'Final',
        'objective_field_type'=> 'numeric',
        'objective_fields'=> ['000005'],
        'objective_fields_names'=> ['Final'],
        'price'=> 0.0,
        'private'=> true,
        'project'=> None,
        'range'=> [1, 80],
        'resource'=> 'timeseries/596a0f66983efc53f3000000',
        'rows'=> 80,
        'shared'=> false,
        'short_url'=> '',
        'size'=> 2691,
        'source'=> 'source/5968ec3c983efc218c000006',
        'source_status'=> true,
        'status'=> {   'code'=> 5,
                       'elapsed'=> 8358,
                       'message'=> 'The time series has been created',
                       'progress'=> 1.0},
        'subscription'=> true,
        'tags'=> [],
        'time_series'=> {   'all_numeric_objectives'=> false,
                            'datasets'=> {   '000005'=> 'dataset/596a0f70983efc53f3000003'},
                            'ets_models'=> {   '000005'=> [   {   'aic'=> 831.30903,
                                                                  'aicc'=> 831.84236,
                                                                  'alpha'=> 0.00012,
                                                                  'beta'=> 0,
                                                                  'bic'=> 840.83713,
                                                                  'final_state'=> {   'b'=> 0,
                                                                                      'l'=> 68.53181,
                                                                                      's'=> [   0]},
                                                                  'gamma'=> 0,
                                                                  'initial_state'=> {   'b'=> 0,
                                                                                        'l'=> 68.53217,
                                                                                        's'=> [   0]},
                                                                  'name'=> 'A,N,N',
                                                                  'period'=> 1,
                                                                  'phi'=> 1,
                                                                  'r_squared'=> -0.0187,
                                                                  'sigma'=> 19.19535},
                                                              {   'aic'=> 834.43049,
                                                                  ...
                                                                  'slope'=> 0.11113,
                                                                  'value'=> 61.39}]},
                            'fields'=> {   '000005'=> {   'column_number'=> 5,
                                                          'datatype'=> 'double',
                                                          'name'=> 'Final',
                                                          'optype'=> 'numeric',
                                                          'order'=> 0,
                                                          'preferred'=> true,
                                                          'summary'=> {   'bins'=> [   [   28.06,
                                                                                           1],
                                                                                       [   34.44,
                                                                                        ...
                                                                                       [   108.335,
                                                                                           2]],
                                                                          ...
                                                                          'sum_squares'=> 389814.3944,
                                                                          'variance'=> 380.73315}}},
                            'period'=> 1,
                            'time_range'=> {   'end'=> 79,
                                               'interval'=> 1,
                                               'interval_unit'=> 'milliseconds',
                                               'start'=> 0}},
        'type'=> 0,
        'updated'=> '2017-07-15T12=>49=>52.549000',
        'white_box'=> false}
        

OptiMLs
-------

An OptiML is the result of an automated optimization process to find the
best model (type and configuration) to solve a particular
classification or regression problem.

The selection process automates the usual time-consuming task of trying
different models and parameters and evaluating their results to find the
best one. Using the OptiML, non-experts can build top-performing models.

You can create an OptiML selecting the ojective field to be predicted, the
evaluation metric to be used to rank the models tested in the process and
a maximum time for the task to be run.

The JSON structure for an OptiML is:

.. code-block:: ruby

    {   'category'=> 0,
        'code'=> 200,
        'configuration'=> nil,
        'configuration_status'=> false,
        'created'=> '2018-05-17T20=>23=>00.060000',
        'creator'=> 'mmartin',
        'dataset'=> 'dataset/5afdb7009252732d930009e8',
        'dataset_status'=> true,
        'datasets'=> [   'dataset/5afde6488bf7d551ee00081c',
                         'dataset/5afde6488bf7d551fd00511f',
                         'dataset/5afde6488bf7d551fe002e0f',
                            ...
                         'dataset/5afde64d8bf7d551fd00512e'],
        'description'=> '',
        'evaluations'=> [   'evaluation/5afde65c8bf7d551fd00514c',
                            'evaluation/5afde65c8bf7d551fd00514f',
                            ...
                            'evaluation/5afde6628bf7d551fd005161'],
        'excluded_fields'=> [],
        'fields_meta'=> {   'count'=> 5,
                            'limit'=> 1000,
                            'offset'=> 0,
                            'query_total'=> 5,
                            'total'=> 5},
        'input_fields'=> ['000000', '000001', '000002', '000003'],
        'model_count'=> {   'logisticregression'=> 1, 'model'=> 8, 'total'=> 9},
        'models'=> [   'model/5afde64e8bf7d551fd005131',
                       'model/5afde64f8bf7d551fd005134',
                       'model/5afde6518bf7d551fd005137',
                       'model/5afde6538bf7d551fd00513a',
                       'logisticregression/5afde6558bf7d551fd00513d',
                       ...
                       'model/5afde65a8bf7d551fd005149'],
        'models_meta'=> {   'count'=> 9, 'limit'=> 1000, 'offset'=> 0, 'total'=> 9},
        'name'=> 'iris',
        'name_options'=> '9 total models (logisticregression=> 1, model=> 8), metric=max_phi, model candidates=18, max. training time=300',
        'objective_field'=> '000004',
        'objective_field_details'=> {   'column_number'=> 4,
                                        'datatype'=> 'string',
                                        'name'=> 'species',
                                        'optype'=> 'categorical',
                                        'order'=> 4},
        'objective_field_name'=> 'species',
        'objective_field_type'=> 'categorical',
        'objective_fields'=> ['000004'],
        'optiml'=> {   'created_resources'=> {   'dataset'=> 10,
                                                 'logisticregression'=> 11,
                                                 'logisticregression_evaluation'=> 11,
                                                 'model'=> 29,
                                                 'model_evaluation'=> 29},
                       'datasets'=> [   {   'id'=> 'dataset/5afde6488bf7d551ee00081c',
                                            'name'=> 'iris',
                                            'name_options'=> '120 instances, 5 fields (1 categorical, 4 numeric), sample rate=0.8'},
                                        {   'id'=> 'dataset/5afde6488bf7d551fd00511f',
                                            'name'=> 'iris',
                                            'name_options'=> '30 instances, 5 fields (1 categorical, 4 numeric), sample rate=0.2, out of bag'},
                                        {   'id'=> 'dataset/5afde6488bf7d551fe002e0f',
                                            'name'=> 'iris',
                                            'name_options'=> '120 instances, 5 fields (1 categorical, 4 numeric), sample rate=0.8'},
                                        ...
                                        {   'id'=> 'dataset/5afde64d8bf7d551fd00512e',
                                            'name'=> 'iris',
                                            'name_options'=> '120 instances, 5 fields (1 categorical, 4 numeric), sample rate=0.8'}],
                       'fields'=> {   '000000'=> {   'column_number'=> 0,
                                                     'datatype'=> 'double',
                                                     'name'=> 'sepal length',
                                                     'optype'=> 'numeric',
                                                     'order'=> 0,
                                                     'preferred'=> true,
                                                     'summary'=> {   'bins'=> [   [   4.3,
                                                                                      1],
                                                                                    ...
                                                                                  [   7.9,
                                                                                      1]],
                                                                     ...
                                                                     'sum'=> 179.9,
                                                                     'sum_squares'=> 302.33,
                                                                     'variance'=> 0.58101}},
                                      '000004'=> {   'column_number'=> 4,
                                                     'datatype'=> 'string',
                                                     'name'=> 'species',
                                                     'optype'=> 'categorical',
                                                     'order'=> 4,
                                                     'preferred'=> true,
                                                     'summary'=> {   'categories'=> [   [   'Iris-setosa',
                                                                                            50],
                                                                                        [   'Iris-versicolor',
                                                                                            50],
                                                                                        [   'Iris-virginica',
                                                                                            50]],
                                                                     'missing_count'=> 0},
                                                     'term_analysis'=> {   'enabled'=> true}}},
                       'max_training_time'=> 300,
                       'metric'=> 'max_phi',
                       'model_types'=> ['model', 'logisticregression'],
                       'models'=> [   {   'evaluation'=> {   'id'=> 'evaluation/5afde65c8bf7d551fd00514c',
                                                             'info'=> {   'accuracy'=> 0.96667,
                                                                          'average_area_under_pr_curve'=> 0.97867,
                                                                          ...
                                                                          'per_class_statistics'=> [   {   'accuracy'=> 1,
                                                                                                           'area_under_pr_curve'=> 1,
                                                                                                           ...
                                                                                                           'spearmans_rho'=> 0.82005}]},
                                                             'metric_value'=> 0.95356,
                                                             'metric_variance'=> 0.00079,
                                                             'name'=> 'iris vs. iris',
                                                             'name_options'=> '279-node, deterministic order, operating kind=probability'},
                                          'evaluation_count'=> 3,
                                          'id'=> 'model/5afde64e8bf7d551fd005131',
                                          'importance'=> [   [   '000002',
                                                                 0.70997],
                                                             [   '000003',
                                                                 0.27289],
                                                             [   '000000',
                                                                 0.0106],
                                                             [   '000001',
                                                                 0.00654]],
                                          'kind'=> 'model',
                                          'name'=> 'iris',
                                          'name_options'=> '279-node, deterministic order'},
                                      {   'evaluation'=> {   'id'=> 'evaluation/5afde65c8bf7d551fd00514f',
                                                             'info'=> {   'accuracy'=> 0.93333,

                                                            ...
                                                             [   '000001',
                                                                 0.02133]],
                                          'kind'=> 'model',
                                          'name'=> 'iris',
                                          'name_options'=> '12-node, randomize, deterministic order, balanced'}],
                       'number_of_model_candidates'=> 18,
                       'recent_evaluations'=> [   0.90764,
                                                  0.94952,
                                                  ...
                                                  0.90427],
                       'search_complete'=> true,
                       'summary'=> {   'logisticregression'=> {   'best'=> 'logisticregression/5afde6558bf7d551fd00513d',
                                                                  'count'=> 1},
                                       'model'=> {   'best'=> 'model/5afde64e8bf7d551fd005131',
                                                     'count'=> 8}}},
        'private'=> true,
        'project'=> nil,
        'resource'=> 'optiml/5afde4a42a83475c1b0008a2',
        'shared'=> false,
        'size'=> 3686,
        'source'=> 'source/5afdb6fb9252732d930009e5',
        'source_status'=> true,
        'status'=> {   'code'=> 5,
                       'elapsed'=> 448878.0,
                       'message'=> 'The optiml has been created',
                       'progress'=> 1},
        'subscription'=> false,
        'tags'=> [],
        'test_dataset'=> nil,
        'type'=> 0,
        'updated'=> '2018-05-17T20=>30=>29.063000'}


Fusions
-------

A Fusion is a special type of composed resource for which all
submodels satisfy the following constraints: they're all either
classifications or regressions over the same kind of data or
compatible fields, with the same objective field. Given those
properties, a fusion can be considered a supervised model,
and therefore one can predict with fusions and evaluate them.
Ensembles can be viewed as a kind of fusion subject to the additional
constraints that all its submodels are tree models that, moreover,
have been built from the same base input data, but sampled in particular ways.

The model types allowed to be a submodel of a fusion are:
deepnet, ensemble, fusion, model, and logistic regression.

The JSON structure for an Fusion is:

.. code-block:: ruby

    {
        "category"=> 0,
        "code"=> 200,
        "configuration"=> null,
        "configuration_status"=> false,
        "created"=> "2018-05-09T20=>11=>05.821000",
        "credits_per_prediction"=> 0,
        "description"=> "",
        "fields_meta"=> {
            "count"=> 5,
            "limit"=> 1000,
            "offset"=> 0,
            "query_total"=> 5,
            "total"=> 5
        },
        "fusion"=> {
            "models"=> [
                {
                    "id"=> "ensemble/5af272eb4e1727d378000050",
                    "kind"=> "ensemble",
                    "name"=> "Iris ensemble",
                    "name_options"=> "boosted trees, 1999-node, 16-iteration, deterministic order, balanced"
                },
                {
                    "id"=> "model/5af272fe4e1727d3780000d6",
                    "kind"=> "model",
                    "name"=> "Iris model",
                    "name_options"=> "1999-node, pruned, deterministic order, balanced"
                },
                {
                    "id"=> "logisticregression/5af272ff4e1727d3780000d9",
                    "kind"=> "logisticregression",
                    "name"=> "Iris LR",
                    "name_options"=> "L2 regularized (c=1), bias, auto-scaled, missing values, eps=0.001"
                }
            ]
        },
        "importance"=> {
            "000000"=> 0.05847,
            "000001"=> 0.03028,
            "000002"=> 0.13582,
            "000003"=> 0.4421
        },
        "model_count"=> {
            "ensemble"=> 1,
            "logisticregression"=> 1,
            "model"=> 1,
            "total"=> 3
        },
        "models"=> [
            "ensemble/5af272eb4e1727d378000050",
            "model/5af272fe4e1727d3780000d6",
            "logisticregression/5af272ff4e1727d3780000d9"
        ],
        "models_meta"=> {
            "count"=> 3,
            "limit"=> 1000,
            "offset"=> 0,
            "total"=> 3
        },
        "name"=> "iris",
        "name_options"=> "3 total models (ensemble=> 1, logisticregression=> 1, model=> 1)",
        "number_of_batchpredictions"=> 0,
        "number_of_evaluations"=> 0,
        "number_of_predictions"=> 0,
        "number_of_public_predictions"=> 0,
        "objective_field"=> "000004",
        "objective_field_details"=> {
            "column_number"=> 4,
            "datatype"=> "string",
            "name"=> "species",
            "optype"=> "categorical",
            "order"=> 4
        },
        "objective_field_name"=> "species",
        "objective_field_type"=> "categorical",
        "objective_fields"=> [
            "000004"
        ],
        "private"=> true,
        "project"=> null,
        "resource"=>"fusion/59af8107b8aa0965d5b61138",
        "shared"=> false,
        "status"=> {
            "code"=> 5,
            "elapsed"=> 8420,
            "message"=> "The fusion has been created",
            "progress"=> 1
        },
        "subscription"=> false,
        "tags"=> [],
        "type"=> 0,
        "updated"=> "2018-05-09T20=>11=>14.258000"
    }


Whizzml Resources
-----------------

Whizzml is a Domain Specific Language that allows the definition and
execution of ML-centric workflows. Its objective is allowing BigML
users to define their own composite tasks, using as building blocks
the basic resources provided by BigML itself. Using Whizzml they can be
glued together using a higher order, functional, Turing-complete language.
The Whizzml code can be stored and executed in BigML using three kinds of
resources: ``Scripts``, ``Libraries`` and ``Executions``.

Whizzml ``Scripts`` can be executed in BigML's servers, that is,
in a controlled, fully-scalable environment which takes care of their
parallelization and fail-safe operation. Each execution uses an ``Execution``
resource to store the arguments and results of the process. Whizzml
``Libraries`` store generic code to be shared of reused in other Whizzml
``Scripts``.

Scripts
-------

In BigML a ``Script`` resource stores Whizzml source code, and the results of
its compilation. Once a Whizzml script is created, it's automatically compiled;
if compilation succeeds, the script can be run, that is,
used as the input for a Whizzml execution resource.

An example of a ``script`` that would create a ``source`` in BigML using the
contents of a remote file is:

.. code-block:: ruby

    require 'bigml'
    api = BigML.Api.new

    # creating a script directly from the source code. This script creates
    # a source uploading data from an s3 repo. You could also create a
    # a script by using as first argument the path to a .whizzml file which
    # contains your source code.

    script = api.create_script("(create-source {\"remote\" \"s3://bigml-public/csv/iris.csv\"})")
    api.ok(script) # waiting for the script compilation to finish
    api.pprint(script['object'])
   
    {"approval_status"=>0,
     "category"=>0,
     "code"=>201,
     "created"=>"2016-06-14T22:16:23.733963",
     "description"=>"",
     "imports"=>[],
     "inputs"=>nil,
     "line_count"=>1,
     "locale"=>"en-US",
     "name"=>"Script",
     "number_of_executions"=>0,
     "outputs"=>nil,
     "price"=>0.0,
     "private"=>true,
     "project"=>nil,
     "provider"=>nil,
     "resource"=>"script/576082377e0a8d0b96004ad3",
     "shared"=>false,
     "size"=>59,
     "source_code"=>
     "(create-source {\"remote\" \"s3://bigml-public/csv/iris.csv\"})",
     "status"=>
      {"code"=>1,
       "message"=>"The script is being processed and will be created soon"},
       "subscription"=>true,
       "tags"=>[],
       "updated"=>"2016-06-14T22:16:23.733982",
       "white_box"=>false}

A ``script`` allows to define some variables as ``inputs``. In the previous
example, no input has been defined, but we could modify our code to
allow the user to set the remote file name as input:

.. code-block:: ruby 

    require 'bigml'
    api = BigML.Api.new
    script = api.create_script("(create-source {\"remote\" my_remote_data})",
                               {"inputs" => [{"name" => "my_remote_data",
                                            "type" => "string",
                                            "default" => "s3://bigml-public/csv/iris.csv",
                                            "description" => "Location of the remote data"}]})

The ``script`` can also use a ``library`` resource (please, see the
``Libraries`` section below for more details) by including its id in the
``imports`` attribute. Other attributes can be checked at the
`API Developers documentation for Scripts<https://bigml.com/developers/scripts#ws_script_arguments>`_.

Executions
----------

To execute in BigML a compiled Whizzml ``script`` you need to create an
``execution`` resource. It's also possible to execute a pipeline of
many compiled scripts in one request.

Each ``execution`` is run under its associated user credentials and its
particular environment constaints. As ``scripts`` can be shared,
you can execute the same ``script``
several times under different
usernames by creating different ``executions``.

As an example of ``execution`` resource, let's create one for the script
in the previous section:

.. code-block:: ruby

    require 'bigml'
    api = BigML.Api.new()
    execution = api.create_execution('script/573c9e2db85eee23cd000489')
    api.ok(execution) # waiting for the execution to finish
    api.pprint(execution['object'])
    {   'category' => 0,
        'code' => 200,
        'created' => '2016-05-18T16:58:01.613000',
        'creation_defaults' => {   },
        'description' => '',
        'execution' => {   'output_resources' => [   {   'code'=> 1,
                                                       'id'=> 'source/573c9f19b85eee23c600024a',
                                                       'last_update' => 1463590681854,
                                                       'progress' => 0.0,
                                                       'state' => 'queued',
                                                       'task' => 'Queuing job',
                                                       'variable' => ''}],
                          'outputs' => [],
                          'result' => 'source/573c9f19b85eee23c600024a',
                          'results' => ['source/573c9f19b85eee23c600024a'],
                          'sources' => [[   'script/573c9e2db85eee23cd000489',
                                              '']],
                          'steps' => 16},
        'inputs' => nil,
        'locale' => 'en-US',
        'name' => "Script's Execution",
        'project' => nil,
        'resource' => 'execution/573c9f19b85eee23bd000125',
        'script' => 'script/573c9e2db85eee23cd000489',
        'script_status' => true,
        'shared' => false,
        'status' => {   'code' => 5,
                       'elapsed' => 249,
                       'elapsed_times' => {   'in-progress' => 247,
                                             'queued' => 62,
                                             'started' => 2},
                       'message' => 'The execution has been created',
                       'progress' => 1.0},
        'subscription' => true,
        'tags' => [],
        'updated' => '2016-05-18T16:58:02.035000'}


An ``execution`` receives inputs, the ones defined in the ``script`` chosen
to be executed, and generates a result. It can also generate outputs.
As you can see, the execution resource contains information about the result
of the execution, the resources that have been generated while executing and
users can define some variables in the code to be exported as outputs. Please
refer to the
`Developers documentation for Executions<https://bigml.com/developers/executions#we_execution_arguments>`_
for details on how to define execution outputs.

Libraries
---------

The ``library`` resource in BigML stores a special kind of compiled Whizzml
source code that only defines functions and constants. The ``library`` is
intended as an import for executable scripts.
Thus, a compiled library cannot be executed, just used as an
import in other ``libraries`` and ``scripts`` (which then have access
to all identifiers defined in the ``library``).

As an example, we build a ``library`` to store the definition of two functions:
``mu`` and ``g``. The first one adds one to the value set as argument and
the second one adds two variables and increments the result by one.

.. code-block:: ruby

    require 'bigml'
    api = BigML::Api.new

    library = api.create_library("(define (mu x) (+ x 1)) (define (g z y) (mu (+ y z)))")
    api.ok(library) 

    api.pprint(library['object'])

    {"approval_status"=>0,
     "category"=>0,
     "code"=>200,
     "created"=>"2016-06-15T10:02:26.001000",
     "description"=>"",
     "exports"=>
        [{"name"=>"mu", "signature"=>["x"]}, {"name"=>"g", "signature"=>["z", "y"]}],
     "imports"=>[],
     "line_count"=>1,
     "name"=>"Library",
     "price"=>0.0,
     "private"=>true,
     "project"=>nil,
     "provider"=>nil,
     "resource"=>"library/576127b2b42eb01edc009ffd",
     "shared"=>false,
     "size"=>53,
     "source_code"=>"(define (mu x) (+ x 1)) (define (g z y) (mu (+ y z)))",
     "status"=>
     {"code"=>5,
      "elapsed"=>2,
      "message"=>"The library has been created",
      "progress"=>1.0},
      "subscription"=>true,
      "tags"=>[],
      "updated"=>"2016-06-15T10:02:26.319000",
      "white_box"=>false}

Libraries can be imported in scripts. The ``imports`` attribute of a ``script``
can contain a list of ``library`` IDs whose defined functions
and constants will be ready to be used throughout the ``script``. Please,
refer to the `API Developers documentation for Libraries<https://bigml.com/developers/libraries#wl_library_arguments>`_
for more details.

Creating Resources
------------------

Newly-created resources are returned in a dictionary with the following
keys:

-  **code**: If the request is successful you will get a
   ``BigML::HTTP_CREATED`` (201) status code. In asynchronous file uploading
   ``api.create_source`` calls, it will contain ``BigML::HTTP_ACCEPTED`` (202)
   status code. Otherwise, it will be
   one of the standard HTTP error codes `detailed in the
   documentation <https://bigml.com/developers/status_codes>`_.
-  **resource**: The identifier of the new resource.
-  **location**: The location of the new resource.
-  **object**: The resource itself, as computed by BigML.
-  **error**: If an error occurs and the resource cannot be created, it
   will contain an additional code and a description of the error. In
   this case, **location**, and **resource** will be ``nil``.


Statuses
~~~~~~~~

Please, bear in mind that resource creation is almost always
asynchronous (**predictions** are the only exception). Therefore, when
you create a new source, a new dataset or a new model, even if you
receive an immediate response from the BigML servers, the full creation
of the resource can take from a few seconds to a few days, depending on
the size of the resource and BigML's load. A resource is not fully
created until its status is ``BigML::FINISHED``. See the
`documentation on status
codes <https://bigml.com/developers/status_codes>`_ for the listing of
potential states and their semantics. So depending on your application
you might need to import the following constants:


.. code-block:: ruby

    BigML::WAITING
    BigML::QUEUED
    BigML::STARTED
    BigML::IN_PROGRESS
    BigML::SUMMARIZED
    BigML::FINISHED
    BigML::UPLOADING
    BigML::FAULTY
    BigML::UNKNOWN
    BigML::RUNNABLE

Usually, you will simply need to wait until the resource is
in the ``bigml.api.FINISHED`` state for further processing. If that's the case,
the easiest way is calling the ``api.ok`` method and passing as first argument
the object that contains your resource:

.. code-block:: ruby

    
    api = BigML::Api.new() # creates a connection to BigML's API
    source = api.create_source('my_file.csv') # creates a source object
    api.ok(source) # checks that the source is finished and updates ``source``

In this code, ``api.create_source`` will probably return a non-finished
``source`` object. Then, ``api.ok`` will query its status and update the
contents of the ``source`` variable with the retrieved information until it
reaches a ``BigML::FINISHED`` or ``BigML::FAILED`` status.

If you don't want the contents of the variable to be updated, you can
also use the ``check_resource`` function:

.. code-block:: ruby

    BigML::check_resource(resource, api.method("get_source"))

that will constantly query the API until the resource gets to a FINISHED or
FAULTY state, or can also be used with ``wait_time`` (in seconds)
and ``retries``
arguments to control the polling:

.. code-block:: ruby

    BigML::check_resource(resource, api.method("get_source"), '', 2, 20)

The ``wait_time`` value is used as seed to a wait
interval that grows exponentially with the number of retries up to the given
``retries`` limit.

However, in other scenarios you might need to control the complete
evolution of the resource, not only its final states.
There, you can query the status of any resource
with the ``status`` method, which simply returns its value and does not
update the contents of the associated variable:

.. code-block:: ruby

    api.status(source)
    api.status(dataset)
    api.status(model)
    api.status(prediction)
    api.status(evaluation)
    api.status(ensemble)
    api.status(batch_prediction)
    api.status(cluster)
    api.status(centroid)
    api.status(batch_centroid)
    api.status(anomaly)
    api.status(anomaly_score)
    api.status(batch_anomaly_score)
    api.status(sample)
    api.status(correlation)
    api.status(statistical_test)
    api.status(logistic_regression)
    api.status(association)
    api.status(association_set)
    api.status(topic_model)
    api.status(topic_distribution)
    api.status(batch_topic_distribution)
    api.status(time_series)
    api.status(forecast)
    api.status(optiml)
    api.status(fusion)
    api.status(script)
    api.status(execution)
    api.status(library)

Remember that, consequently, you will need to retrieve the resources
explicitly in your code to get the updated information.


Projects
~~~~~~~~

A special kind of resource is ``project``. Projects are repositories
for resources, intended to fulfill organizational purposes. Each project can
contain any other kind of resource, but the project that a certain resource
belongs to is determined by the one used in the ``source``
they are generated from. Thus, when a source is created
and assigned a certain ``project_id``, the rest of resources generated from
this source will remain in this project.

The REST calls to manage the ``project`` resemble the ones used to manage the
rest of resources. When you create a ``project``:

.. code-block:: ruby

    require 'bigml'
    api = BigML::Api.new

    project = api.create_project({'name' => 'my first project'})

the resulting resource is similar to the rest of resources, although shorter:

.. code-block:: ruby

    {'code' => 201,
     'resource' => u'project/54a1bd0958a27e3c4c0002f0',
     'location' => 'http://bigml.io/andromeda/project/54a1bd0958a27e3c4c0002f0',
     'object' => {u'category' => 0,
                'updated' => u'2014-12-29T20:43:53.060045',
                'resource' => u'project/54a1bd0958a27e3c4c0002f0',
                'name' => u'my first project',
                'created' => u'2014-12-29T20:43:53.060013',
                'tags' => [],
                'private' => true,
                'dev' => nil,
                'description' => u''},
     'error' => nil}

and you can use its project id to get, update or delete it:

.. code-block:: ruby

    project = api.get_project('project/54a1bd0958a27e3c4c0002f0')
    api.update_project(project['resource'],
                       {'description' => 'This is my first project'})

    api.delete_project(project['resource'])

**Important**: Deleting a non-empty project will also delete **all resources**
assigned to it, so please be extra-careful when using
the ``api.delete_project`` call.

Creating sources
~~~~~~~~~~~~~~~~

To create a source from a local data file, you can use the
``create_source`` method. The only required parameter is the path to the
data file (or file-like object). You can use a second optional parameter
to specify any of the
options for source creation described in the `BigML API
documentation <https://bigml.com/developers/sources>`_.

Here's a sample invocation:

.. code-block:: ruby 

    require 'bigml'
    api = BigML::Api.new

    source = api.create_source('./data/iris.csv',
        {'name' => 'my source', 'source_parser' => {'missing_tokens' => ['?']}})

or you may want to create a source from a file in a remote location:

.. code-block:: ruby 

    source = api.create_source('s3://bigml-public/csv/iris.csv',
        {'name' => 'my remote source', 'source_parser' => {'missing_tokens' => ['?']}})

As already mentioned, source creation is asynchronous. In both these examples,
the ``api.create_source`` call returns once the file is uploaded.
Then ``source`` will contain a resource whose status code will be either
``WAITING`` or ``QUEUED``.

You can retrieve the updated status at any time using the corresponding get
method. For example, to get the status of our source we would use:

.. code-block:: ruby

    api.status(source)


Creating datasets
~~~~~~~~~~~~~~~~~

Once you have created a source, you can create a dataset. The only
required argument to create a dataset is a source id. You can add all
the additional arguments accepted by BigML and documented in the
`Datasets section of the Developer's
documentation <https://bigml.com/developers/datasets>`_.

For example, to create a dataset named "my dataset" with the first 1024
bytes of a source, you can submit the following request:

.. code-block:: ruby

    dataset = api.create_dataset(source, {"name" => "my dataset", "size" => 1024})

Upon success, the dataset creation job will be queued for execution, and
you can follow its evolution using ``api.status(dataset)``.

As for the rest of resources, the create method will return an incomplete
object, that can be updated by issuing the corresponding
``api.get_dataset`` call until it reaches a ``FINISHED`` status.
Then you can export the dataset data to a CSV file using:

.. code-block:: ruby 

    api.download_dataset('dataset/526fc344035d071ea3031d75',
        filename='my_dir/my_dataset.csv')

You can also extract samples from an existing dataset and generate a new one
with them using the ``api.create_dataset`` method. The first argument should
be the origin dataset and the rest of arguments that set the range or the
sampling rate should be passed as a dictionary. For instance, to create a new
dataset extracting the 80% of instances from an existing one, you could use:

.. code-block:: ruby

    dataset = api.create_dataset(origin_dataset, {"sample_rate" => 0.8})

Similarly, if you want to split your source into training and test datasets,
you can set the `sample_rate` as before to create the training dataset and
use the `out_of_bag` option to assign the complementary subset of data to the
test dataset. If you set the `seed` argument to a value of your choice, you
will ensure a determinist sampling, so that each time you execute this call
you will get the same datasets as a result and they will be complementary:

.. code-block:: ruby

    origin_dataset = api.create_dataset(source)
    train_dataset = api.create_dataset(
        origin_dataset, {"name" => "Dataset Name | Training",
                         "sample_rate" => 0.8, "seed" => "my seed"})
    test_dataset = api.create_dataset(
        origin_dataset, {"name" => "Dataset Name | Test",
                         "sample_rate" => 0.8, "seed" => "my seed",
                         "out_of_bag" => true})

Sometimes, like for time series evaluations, it's important that the data
in your train and test datasets is ordered. In this case, the split
cannot be done at random. You will need to start from an ordered dataset and
decide the ranges devoted to training and testing using the ``range``
attribute:

.. code-block:: ruby

    origin_dataset = api.create_dataset(source)
    train_dataset = api.create_dataset(
        origin_dataset, {"name" => "Dataset Name | Training",
                         "range" => [1, 80]})
    test_dataset = api.create_dataset(
        origin_dataset, {"name" => "Dataset Name | Test",
                         "range" => [81, 100]})
                         
It is also possible to generate a dataset from a list of datasets
(multidataset):

.. code-block:: ruby

    dataset1 = api.create_dataset(source1)
    dataset2 = api.create_dataset(source2)
    multidataset = api.create_dataset([dataset1, dataset2])

Clusters can also be used to generate datasets containing the instances
grouped around each centroid. You will need the cluster id and the centroid id
to reference the dataset to be created. For instance,

.. code-block:: ruby

    cluster = api.create_cluster(dataset)
    cluster_dataset_1 = api.create_dataset(cluster,
                                           args={'centroid' => '000000'})

would generate a new dataset containing the subset of instances in the cluster
associated to the centroid id ``000000``.


Creating models
~~~~~~~~~~~~~~~

Once you have created a dataset you can create a model from it. If you don't
select one, the model will use the last field of the dataset as objective
field. The only required argument to create a model is a dataset id.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Models section of the Developer's
documentation <https://bigml.com/developers/models>`_.

For example, to create a model only including the first two fields and
the first 10 instances in the dataset, you can use the following
invocation:

.. code-block:: ruby

    model = api.create_model(dataset, {
        "name" => "my model", "input_fields" => ["000000", "000001"], "range" => [1, 10]})

Again, the model is scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(model)``.

Models can also be created from lists of datasets. Just use the list of ids
as the first argument in the api call

.. code-block:: ruby 

    model = api.create_model([dataset1, dataset2], {
        "name" => "my model", "input_fields" => ["000000", "000001"], "range" => [1, 10]})

And they can also be generated as the result of a clustering procedure. When
a cluster is created, a model that predicts if a certain instance belongs to
a concrete centroid can be built by providing the cluster and centroid ids:

.. code-block:: ruby

    model = api.create_model(cluster, {
        "name" => "model for centroid 000001", "centroid" => "000001"})

if no centroid id is provided, the first one appearing in the cluster is used.

Creating clusters
~~~~~~~~~~~~~~~~~

If your dataset has no fields showing the objective information to
predict for the training data, you can still build a cluster
that will group similar data around
some automatically chosen points (centroids). Again, the only required
argument to create a cluster is the dataset id. You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Clusters section of the Developer's
documentation <https://bigml.com/developers/clusters>`_.

Let's create a cluster from a given dataset:

.. code-block:: ruby

    cluster = api.create_cluster(dataset, {"name" => "my cluster",
                                           "k" => 5})

that will create a cluster with 5 centroids.

Creating anomaly detectors
~~~~~~~~~~~~~~~~~~~~~~~~~~

If your problem is finding the anomalous data in your dataset, you can
build an anomaly detector, that will use iforest to single out the
anomalous records. Again, the only required
argument to create an anomaly detector is the dataset id. You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Anomaly detectors section of the Developer's
documentation <https://bigml.com/developers/anomalies>`_.

Let's create an anomaly detector from a given dataset:

.. code-block:: ruby

    anomaly = api.create_anomaly(dataset, {"name" => "my anomaly"})

that will create an anomaly resource with a `top_anomalies` block of the
most anomalous points.

Creating associations
~~~~~~~~~~~~~~~~~~~~~

To find relations between the field values you can create an association
discovery resource. The only required argument to create an association
is a dataset id.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Association section of the Developer's
documentation <https://bigml.com/developers/associations>`_.

For example, to create an association only including the first two fields and
the first 10 instances in the dataset, you can use the following
invocation:

.. code-block:: ruby

    model = api.create_association(dataset, {
        "name" => "my association", "input_fields" => ["000000", "000001"],
        "range" => [1, 10]})

Again, the association is scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(association)``.

Associations can also be created from lists of datasets. Just use the
list of ids as the first argument in the api call

.. code-block:: ruby 

    model = api.create_association([dataset1, dataset2], {
        "name" => "my association", "input_fields" => ["000000", "000001"],
        "range" => [1, 10]})


Creating topic models
~~~~~~~~~~~~~~~~~~~~~

To find which topics do your documents refer to you can create a topic model.
The only required argument to create a topic model
is a dataset id.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Topic Model section of the Developer's
documentation <https://bigml.com/api/topicmodels>`_.

For example, to create a topic model including exactly 32 topics
you can use the following
invocation:

.. code-block:: ruby

    topic_model = api.create_topic_model(dataset,
        {"name" => "my topics", "number_of_topics" => 32})

Again, the topic model is scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(topic_model)``.

Topic models can also be created from lists of datasets. Just use the
list of ids as the first argument in the api call

.. code-block:: ruby

    topic_model = api.create_topic_model([dataset1, dataset2],
        {"name" => "my topics", "number_of_topics" => 32})

Creating time series
~~~~~~~~~~~~~~~~~~~~

To forecast the behaviour of any numeric variable that depends on its
historical records you can use a time series.
The only required argument to create a time series
is a dataset id.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Time Series section of the Developer's
documentation <https://bigml.com/api/timeseries>`_.

For example, to create a time series including a forecast of 10 points
for the numeric values you can use the following
invocation:

.. code-block:: ruby

    time_series = api.create_time_series(dataset,
        {"name" => "my time series", "horizon" => 10})

Again, the time series is scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(time_series)``.

Time series also be created from lists of datasets. Just use the
list of ids as the first argument in the api call

.. code-block:: ruby

    time_series = api.create_time_series([dataset1, dataset2],
        {"name" => "my time series", "horizon" => 10})

Creating OptiML
~~~~~~~~~~~~~~~

To create an OptiML, the only required argument is a dataset id.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `OptiML section of the Developer's
documentation <https://bigml.com/api/optimls>`_.

For example, to create an OptiML which optimizes the accuracy of the model you
can use the following method

.. code-block:: ruby

    optiml = api.create_optiml(dataset, {
        "name" => "my optiml", "metric" => "accuracy"})

The OptiML is then scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(optiml)``.


Creating Fusion
~~~~~~~~~~~~~~~

To create a Fusion, the only required argument is a list of models.
You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Fusion section of the Developer's
documentation <https://bigml.com/api/fusions>`_.

For example, to create a Fusion you can use this connection method:

.. code-block:: ruby

    fusion = api.create_fusion(["model/5af06df94e17277501000010"
                                "model/5af06df84e17277502000019"
                                "deepnet/5af06df84e17277502000016"
                                "ensemble/5af06df74e1727750100000d"],
                                {"name" => "my fusion"})

The Fusion is then scheduled for creation, and you can retrieve its
status at any time by means of ``api.status(fusion)``.

Fusions can also be created by assigning some weights to each model in the
list. In this case, the argument for the create call will be a list of
dictionaries that contain the ``id`` and ``weight`` keys:

.. code-block:: ruby

    fusion = api.create_fusion([{"id" => "model/5af06df94e17277501000010",
                                 "weight" => 10},
                                {"id" => "model/5af06df84e17277502000019",
                                 "weight" => 20},
                                {"id" => "deepnet/5af06df84e17277502000016",
                                 "weight" => 5}],
                                {"name" => "my weighted fusion"})
                                
Creating predictions
~~~~~~~~~~~~~~~~~~~~

You can now use the model resource identifier together with some input
parameters to ask for predictions, using the ``create_prediction``
method. You can also give the prediction a name:

.. code-block:: ruby

    prediction = api.create_prediction(model,
                                       {"sepal length" => 5,
                                       "sepal width" => 2.5},
                                       {"name" => "my prediction"})

To see the prediction you can use ``pprint``:

.. code-block:: ruby

    api.pprint(prediction)

Predictions can be created using any supervised model (model, ensemble,
logistic regression, deepnet and fusion) as first argument.

Creating centroids
~~~~~~~~~~~~~~~~~~

To obtain the centroid associated to new input data, you
can now use the ``create_centroid`` method. Give the method a cluster
identifier and the input data to obtain the centroid.
You can also give the centroid predicition a name:

.. code-block:: ruby

    centroid = api.create_centroid(cluster,
                                   {"pregnancies" => 0,
                                    "plasma glucose" => 118,
                                    "blood pressure" => 84,
                                    "triceps skin thickness" => 47,
                                    "insulin" => 230,
                                    "bmi" => 45.8,
                                    "diabetes pedigree" => 0.551,
                                    "age" => 31,
                                    "diabetes" => "true"},
                                    {"name" => "my centroid"})
                                    

Creating anomaly scores
~~~~~~~~~~~~~~~~~~~~~~~

To obtain the anomaly score associated to new input data, you
can now use the ``create_anomaly_score`` method. Give the method an anomaly
detector identifier and the input data to obtain the score:

.. code-block:: ruby

    anomaly_score = api.create_anomaly_score(anomaly, {"src_bytes" => 350},
                                             args={"name" => "my score"})

Creating association sets
~~~~~~~~~~~~~~~~~~~~~~~~~

Using the association resource, you can obtain the consequent items associated
by its rules to your input data. These association sets can be obtained calling
the ``create_association_set`` method. The first argument is the association
ID or object and the next one is the input data.

.. code-block:: ruby 

    association_set = api.create_association_set(association, {"genres" => "Action$Adventure"}, 
                                                        args={"name" => "my association set"})
 
Creating topic distributions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To obtain the topic distributions associated to new input data, you
can now use the ``create_topic_distribution`` method. Give
the method a topic model identifier and the input data to obtain the score:

.. code-block:: ruby

    topic_distribution = api.create_topic_distribution(
         topic_model,
         {"Message" => "The bubble exploded in 2007."},
         {"name" => "my topic distribution"})


Creating forecasts
~~~~~~~~~~~~~~~~~~

To obtain the forecast associated to a numeric variable, you
can now use the ``create_forecast`` method. Give
the method a time series identifier and the input data to obtain the forecast:

.. code-block:: ruby

    forecast = api.create_forecast(
        time_series,
        {"Final" => {"horizon" => 10}})


Creating evaluations
~~~~~~~~~~~~~~~~~~~~

Once you have created a model, you can measure its perfomance by running a
dataset of test data through it and comparing its predictions to the objective
field real values. Thus, the required arguments to create an evaluation are
model id and a dataset id. You can also
include in the request all the additional arguments accepted by BigML
and documented in the `Evaluations section of the Developer's
documentation <https://bigml.com/developers/evaluations>`_.

For instance, to evaluate a previously created model using an existing dataset
you can use the following call:

.. code-block:: ruby

    evaluation = api.create_evaluation(model, dataset, {
        "name" => "my model"})

Again, the evaluation is scheduled for creation and ``api.status(evaluation)``
will show its state.

Evaluations can also check the ensembles' performance. To evaluate an ensemble
you can do exactly what we just did for the model case, using the ensemble
object instead of the model as first argument:

.. code-block:: ruby

    evaluation = api.create_evaluation(ensemble, dataset)

Evaluations can be created using any supervised model (including time series)
as first argument.

Creating ensembles
~~~~~~~~~~~~~~~~~~

To improve the performance of your predictions, you can create an ensemble
of models and combine their individual predictions.
The only required argument to create an ensemble is the dataset id:

.. code-block:: ruby

    ensemble = api.create_ensemble('dataset/5143a51a37203f2cf7000972')

BigML offers three kinds of ensembles. Two of them are known as ``Decision
Forests`` because they are built as collections of ``Decision trees``
whose predictions
are aggregated using different combiners (``plurality``,
``confidence weighted``, ``probability weighted``) or setting a ``threshold``
to issue the ensemble's
prediction. All ``Decision Forests`` use bagging to sample the
data used to build the underlying models.

As an example of how to create a ``Decision Forest``
with `20` models, you only need to provide the dataset ID that you want to
build the ensemble from and the number of models:

.. code-block:: ruby

    args = {'number_of_models' => 20}
    ensemble = api.create_ensemble('dataset/5143a51a37203f2cf7000972', args)

If no ``number_of_models`` is provided, the ensemble will contain 10 models.

``Random Decision Forests`` fall
also into the ``Decision Forest`` category,
but they only use a subset of the fields chosen
at random at each split. To create this kind of ensemble, just use the
``randomize`` option:

.. code-block:: ruby

    args = {'number_of_models' => 20, 'randomize' => true}
    ensemble = api.create_ensemble('dataset/5143a51a37203f2cf7000972', args)

The third kind of ensemble is ``Boosted Trees``. This type of ensemble uses
quite a different algorithm. The trees used in the ensemble don't have as
objective field the one you want to predict, and they don't aggregate the
underlying models' votes. Instead, the goal is adjusting the coefficients
of a function that will be used to predict. The
models' objective is, therefore, the gradient that minimizes the error
of the predicting function (when comparing its output
with the real values). The process starts with
some initial values and computes these gradients. Next step uses the previous
fields plus the last computed gradient field as
the new initial state for the next iteration.
Finally, it stops when the error is smaller than a certain threshold
or iterations reach a user-defined limit.
In classification problems, every category in the ensemble's objective field
would be associated with a subset of the ``Boosted Trees``. The objective of
each subset of trees
is adjustig the function to the probability of belonging
to this particular category.

In order to build
an ensemble of ``Boosted Trees`` you need to provide the ``boosting``
attributes. You can learn about the existing attributes in the `ensembles'
section of the API documentation <https://bigml.com/api/ensembles#es_gradient_boosting>`_,
but a typical attribute to be set would
be the maximum number of iterations:

.. code-block:: ruby

    args = {'boosting' => {'iterations' => 20}}
    ensemble = api.create_ensemble('dataset/5143a51a37203f2cf7000972', args)

Creating logistic regressions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

For classification problems, you can choose also logistic regressions to model
your data. Logistic regressions compute a probability associated to each class
in the objective field. The probability is obtained using a logistic
function, whose argument is a linear combination of the field values.

As the rest of models, logistic regressions can be created from a dataset by
calling the corresponding create method:

.. code-block:: ruby

    logistic_regression = api.create_logisticregression(
        'dataset/5143a51a37203f2cf7000972',
        {"name" => "my logistic regression",
         "objective_field" => "my_objective_field"})

In this example, we created a logistic regression named
``my logistic regression`` and set the objective field to be
``my_objective_field``. Other arguments, like ``bias``, ``missing_numerics``
and ``c`` can also be specified as attributes in arguments dictionary at
creation time.
Particularly for categorical fields, there are four different available
`field_codings`` options (``dummy``, ``contrast``, ``other`` or the ``one-hot``
default coding). For a more detailed description of the
``field_codings`` attribute and its syntax, please see the `Developers API
Documentation
<https://bigml.com/api/logisticregressions#lr_logistic_regression_arguments>`_.


Creating deepnets
~~~~~~~~~~~~~~~~~

Deepnets can also solve classification and regression problems.
Deepnets are an optimized version of Deep Neural Networks,
a class of machine-learned models inspired by the neural
circuitry of the human brain. In these classifiers, the input features
are fed to a group of "nodes" called a "layer".
Each node is essentially a function on the input that
transforms the input features into another value or collection of values.
Then the entire layer transforms an input vector into a new "intermediate"
feature vector. This new vector is fed as input to another layer of nodes.
This process continues layer by layer, until we reach the final "output"
layer of nodes, where the output is the network’s prediction: an array
of per-class probabilities for classification problems or a single,
real value for regression problems.

Deepnets predictions compute a probability associated to each class
in the objective field for classification problems.
As the rest of models, deepnets can be created from a dataset by
calling the corresponding create method:

.. code-block:: ruby

    deepnet = api.create_deepnet(
        'dataset/5143a51a37203f2cf7000972',
        {"name" => "my deepnet",
         "objective_field" => "my_objective_field"})

In this example, we created a deepnet named
``my deepnet`` and set the objective field to be
``my_objective_field``. Other arguments, like ``number_of_hidden_layers``,
``learning_rate``
and ``missing_numerics`` can also be specified as attributes
in an arguments dictionary at
creation time. For a more detailed description of the
available attributes and its syntax, please see the `Developers API
Documentation
<https://bigml.com/api/deepnets#dn_deepnet_arguments>`_.


Creating batch predictions
~~~~~~~~~~~~~~~~~~~~~~~~~~

We have shown how to create predictions individually, but when the amount
of predictions to make increases, this procedure is far from optimal. In this
case, the more efficient way of predicting remotely is to create a dataset
containing the input data you want your model to predict from and to give its
id and the one of the model to the ``create_batch_prediction`` api call:

.. code-block:: ruby

    batch_prediction = api.create_batch_prediction(model, dataset, {
        "name" => "my batch prediction", "all_fields" => true,
        "header" => true,
        "confidence" => true})

In this example, setting ``all_fields`` to true causes the input
data to be included in the prediction output, ``header`` controls whether a
headers line is included in the file or not and ``confidence`` set to true
causes the confidence of the prediction to be appended. If none of these
arguments is given, the resulting file will contain the name of the
objective field as a header row followed by the predictions.

As for the rest of resources, the create method will return an incomplete
object, that can be updated by issuing the corresponding
``api.get_batch_prediction`` call until it reaches a ``FINISHED`` status.
Then you can download the created predictions file using:

.. code-block:: ruby

    api.download_batch_prediction('batchprediction/526fc344035d071ea3031d70',
                                  'my_dir/my_predictions.csv')

The output of a batch prediction can also be transformed to a source object
using the ``source_from_batch_prediction`` method in the api:

.. code-block:: ruby

    api.source_from_batch_prediction(
        'batchprediction/526fc344035d071ea3031d70',
         {'name' => 'my_batch_prediction_source'})

This code will create a new source object, that can be used again as starting
point to generate datasets.

Creating batch centroids
~~~~~~~~~~~~~~~~~~~~~~~~

As described in the previous section, it is also possible to make centroids'
predictions in batch. First you create a dataset
containing the input data you want your cluster to relate to a centroid.
The ``create_batch_centroid`` call will need the id of the input
data dataset and the
cluster used to assign a centroid to each instance:

.. code-block:: ruby

    batch_centroid = api.create_batch_centroid(cluster, dataset, {
        "name" => "my batch centroid", "all_fields" => true,
        "header" => true})

Creating batch anomaly scores
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Input data can also be assigned an anomaly score in batch. You train an
anomaly detector with your training data and then build a dataset from your
input data. The ``create_batch_anomaly_score`` call will need the id
of the dataset and of the
anomaly detector to assign an anomaly score to each input data instance:

.. code-block:: ruby 

    batch_anomaly_score = api.create_batch_anomaly_score(anomaly, dataset, {
        "name" => "my batch anomaly score", "all_fields" => true,
        "header" => true})

Creating batch topic distributions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Input data can also be assigned a topic distribution in batch. You train a
topic model with your training data and then build a dataset from your
input data. The ``create_batch_topic_distribution`` call will need the id
of the dataset and of the
topic model to assign a topic distribution to each input data instance:

.. code-block:: ruby

    batch_topic_distribution = api.create_batch_topic_distribution(
        topic_model, dataset, {
        "name" => "my batch topic distribution", "all_fields" => true,
        "header" => true})



Reading Resources
-----------------

When retrieved individually, resources are returned as a dictionary
identical to the one you get when you create a new resource. However,
the status code will be ``BigML::HTTP_OK`` if the resource can be
retrieved without problems, or one of the HTTP standard error codes
otherwise.

Listing Resources
-----------------

You can list resources with the appropriate api method:

.. code-block:: ruby 

    api.list_sources()
    api.list_datasets()
    api.list_models()
    api.list_predictions()
    api.list_evaluations()
    api.list_ensembles()
    api.list_batch_predictions()
    api.list_clusters()
    api.list_centroids()
    api.list_batch_centroids()
    api.list_anomalies()
    api.list_anomaly_scores()
    api.list_batch_anomaly_scores()
    api.list_projects()
    api.list_samples()
    api.list_correlations()
    api.list_statistical_tests()
    api.list_logistic_regressions()
    api.list_associations()
    api.list_association_sets()
    api.list_topic_models()
    api.list_topic_distributions()
    api.list_batch_topic_distributions()
    api.list_time_series()
    api.list_deepnets()
    api.list_forecasts()
    api.list_scripts()
    api.list_libraries()
    api.list_executions()
    api.list_fusions()
    api.list_optimls()


you will receive a dictionary with the following keys:

-  **code**: If the request is successful you will get a
   ``BigML::HTTP_OK`` (200) status code. Otherwise, it will be one of
   the standard HTTP error codes. See `BigML documentation on status
   codes <https://bigml.com/developers/status_codes>`_ for more info.
-  **meta**: A dictionary including the following keys that can help you
   paginate listings:

   -  **previous**: Path to get the previous page or ``nil`` if there
      is no previous page.
   -  **next**: Path to get the next page or ``nil`` if there is no
      next page.
   -  **offset**: How far off from the first entry in the resources is
      the first one listed in the resources key.
   -  **limit**: Maximum number of resources that you will get listed in
      the resources key.
   -  **total\_count**: The total number of resources in BigML.

-  **objects**: A list of resources as returned by BigML.
-  **error**: If an error occurs and the resource cannot be created, it
   will contain an additional code and a description of the error. In
   this case, **meta**, and **resources** will be ``nil``.

Filtering Resources
~~~~~~~~~~~~~~~~~~~

You can filter resources in listings using the syntax and fields labeled
as *filterable* in the `BigML
documentation <https://bigml.com/developers>`_ for each resource.

A few examples:

Ids of the first 5 sources created before April 1st, 2012
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_sources("limit=5;created__lt=2012-04-1")['objects'].collect { |it| it["resource"] }

Name of the first 10 datasets bigger than 1MB
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_datasets("limit=10;size__gt=1048576")['objects'].collect { |it| it["name"] }

Name of models with more than 5 fields (columns)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_models("columns__gt=5")['objects'].collect { |it| it["name"] }

Ids of predictions whose model has not been deleted
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_predictions("model_status=true")['objects'].collect { |it| it["resource"] } 

Ordering Resources
~~~~~~~~~~~~~~~~~~

You can order resources in listings using the syntax and fields labeled
as *sortable* in the `BigML
documentation <https://bigml.com/developers>`_ for each resource.

A few examples:

Name of sources ordered by size
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_sources("order_by=size")['objects'].collect { |it| it["name] }

Number of instances in datasets created before April 1st, 2012 ordered by size
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_datasets("created__lt=2012-04-1;order_by=size")['objects'].collect { |it| it["rows"] }


Model ids ordered by number of predictions (in descending order).
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_models("order_by=-number_of_predictions")['objects'].collect { |it| it["resource"] }

Name of predictions ordered by name.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: ruby 

    api.list_predictions("order_by=name")['objects'].collect { |it| it["name"] }


Updating Resources
------------------

When you update a resource, it is returned in a dictionary exactly like
the one you get when you create a new one. However the status code will
be ``BigML::HTTP_ACCEPTED`` if the resource can be updated without
problems or one of the HTTP standard error codes otherwise.

.. code-block:: ruby

    api.update_source(source, {"name" => "new name"})
    api.update_dataset(dataset, {"name" => "new name"})
    api.update_model(model, {"name" => "new name"})
    api.update_prediction(prediction, {"name" => "new name"})
    api.update_evaluation(evaluation, {"name" => "new name"})
    api.update_ensemble(ensemble, {"name" => "new name"})
    api.update_batch_prediction(batch_prediction, {"name" => "new name"})
    api.update_cluster(cluster, {"name" => "new name"})
    api.update_centroid(centroid, {"name" => "new name"})
    api.update_batch_centroid(batch_centroid, {"name" => "new name"})
    api.update_anomaly(anomaly, {"name" => "new name"})
    api.update_anomaly_score(anomaly_score, {"name" => "new name"})
    api.update_batch_anomaly_score(batch_anomaly_score, {"name" => "new name"})
    api.update_project(project, {"name" => "new name"})
    api.update_correlation(correlation, {"name" => "new name"})
    api.update_statistical_test(statistical_test, {"name" => "new name"})
    api.update_logisticregression(logistic_regression, {"name" => "new name"})
    api.update_association(association, {"name" => "new name"})
    api.update_association_set(association_set, {"name" => "new name"})
    api.update_topic_model(topic_model, {"name" => "new name"})
    api.update_topic_distribution(topic_distribution, {"name" => "new name"})
    api.update_batch_topic_distribution(batch_topic_distribution, {"name" => "new name"})
    api.update_time_series(time_series, {"name" => "new name"})
    api.update_forecast(forecast, {"name" => "new name"})
    api.update_deepnet(deepnet, {"name" => "new name"})
    api.update_script(script, {"name" => "new name"})
    api.update_library(library, {"name" => "new name"})
    api.update_execution(execution, {"name" => "new name"})
    api.update_optiml(optiml, {"name" => "new name"})
    api.update_fusion(fusion, {"name" => "new name"})

Updates can change resource general properties, such as the ``name`` or
``description`` attributes of a dataset, or specific properties. As an example,
let's say that your source has a certain field whose contents are
numeric integers. BigML will assign a numeric type to the field, but you
might want it to be used as a categorical field. You could change
its type to ``categorical`` by calling:

.. code-block:: ruby

    api.update_source(source, {"fields" => {"000001" => {"optype" => "categorical"}}})


where ``000001`` is the field id that corresponds to the updated field.

Another usually needed update is changing a fields' ``non-preferred``
attribute,
so that it can be used in the modeling process:


.. code-block:: ruby

    api.update_dataset(dataset, {"fields" => {"000001" => {"preferred" => true}}})

where you would be setting as ``preferred`` the field whose id is ``000001``.

You may also want to change the name of one of the clusters found in your
clustering:


.. code-block:: ruby

    api.update_cluster(cluster, \
        {"clusters" => {"000001" => {"name" => "my cluster"}}})

which is changing the name of the cluster whose centroid id is ``000001`` to
``my_cluster``. Or, similarly, changing the name of one detected topic:


.. code-block:: ruby

    api.update_topic_model(topic_model, \
        {"topics" => {"000001" => {"name" => "my topic"}}})


You will find detailed information about
the updatable attributes of each resource in
`BigML developer's documentation <https://bigml.com/api>`_.


Deleting Resources
------------------

Resources can be deleted individually using the corresponding method for
each type of resource.

.. code-block:: ruby

    api.delete_source(source)
    api.delete_dataset(dataset)
    api.delete_model(model)
    api.delete_prediction(prediction)
    api.delete_evaluation(evaluation)
    api.delete_ensemble(ensemble)
    api.delete_batch_prediction(batch_prediction)
    api.delete_cluster(cluster)
    api.delete_centroid(centroid)
    api.delete_batch_centroid(batch_centroid)
    api.delete_anomaly(anomaly)
    api.delete_anomaly_score(anomaly_score)
    api.delete_batch_anomaly_score(batch_anomaly_score)
    api.delete_sample(sample)
    api.delete_correlation(correlation)
    api.delete_statistical_test(statistical_test)
    api.delete_logistic_regression(logistic_regression)
    api.delete_association(association)
    api.delete_association_set(association_set)
    api.delete_topic_model(topic_model)
    api.delete_topic_distribution(topic_distribution)
    api.delete_batch_topic_distribution(batch_topic_distribution)
    api.delete_time_series(time_series)
    api.delete_forecast(forecast)
    api.delete_deepnet(deepnet)
    api.delete_project(project)
    api.delete_script(script)
    api.delete_library(library)
    api.delete_execution(execution)
    api.delete_fusion(fusion)
    api.delete_optiml(optiml)

Each of the calls above will return a dictionary with the following
keys:

-  **code** If the request is successful, the code will be a
   ``BigML::HTTP_NO_CONTENT`` (204) status code. Otherwise, it wil be
   one of the standard HTTP error codes. See the `documentation on
   status codes <https://bigml.com/developers/status_codes>`_ for more
   info.
-  **error** If the request does not succeed, it will contain a
   dictionary with an error code and a message. It will be ``nil``
   otherwise.
   
Public and shared resources
---------------------------

The previous examples use resources that were created by the same user
that asks for their retrieval or modification. If a user wants to share one
of her resources, she can make them public or share them. Declaring a resource
public means that anyone can see the resource. This can be applied to datasets
and models. To turn a dataset public, just update its ``private`` property:

.. code-block:: ruby

    api.update_dataset('dataset/5143a51a37203f2cf7000972', {'private' => false})

and any user will be able to download it using its id prepended by ``public``:

.. code-block:: ruby

    api.get_dataset('public/dataset/5143a51a37203f2cf7000972')

In the models' case, you can also choose if you want the model to be fully
downloadable or just accesible to make predictions. This is controlled with the
``white_box`` property. If you want to publish your model completely, just
use:

.. code-block:: ruby 

    api.update_model('model/5143a51a37203f2cf7000956', {'private' => false,
                     'white_box' => true})

Both public models and datasets, will be openly accessible for anyone,
registered or not, from the web
gallery.


Still, you may want to share your models with other users, but without making
them public for everyone. This can be achieved by setting the ``shared``
property:

.. code-block:: ruby

    api.update_model('model/5143a51a37203f2cf7000956', {'shared' => true})

Shared models can be accessed using their share hash (propery ``shared_hash``
in the original model):

.. code-block:: ruby

    api.get_model('shared/model/d53iw39euTdjsgesj7382ufhwnD')

or by using their original id with the creator user as username and a specific
sharing api_key you will find as property ``sharing_api_key`` in the updated
model:

.. code-block:: ruby

    api.get_model('model/5143a51a37203f2cf7000956', '', 'creator',
                  'c972018dc5f2789e65c74ba3170fda31d02e00c3')


Only users with the share link or credentials information will be able to
access your shared models.

Local Resources
---------------

All the resources in BigML can be downloaded and used locally with no
connection whatsoever to BigML's servers. This is specially important
for all Supervised and Unsupervised models, that can be used to generate
predictions in any programmable device. The next sections describe how to
do that for each type of resource, but as a general rule, resources can be
exported to a JSON file in your file system using the ``export`` method.

.. code-block:: ruby

    api.export('model/5143a51a37203f2cf7000956',
               'my_dir/my_model.json')

In the case of models that can be represented in a `PMML` syntax, the
export method can be used to produce the corresponding `PMML` file

.. code-block:: ruby
    api.export('model/5143a51a37203f2cf7000956',
               'my_dir/my_model.pmml',
               true)

The contents of the generated file can be used just as the remote model
to generate predictions. As you'll see in next section, the local ``Model``
object can be instantiated by giving the path to this file as first argument:

.. code-block:: ruby

    local_model = BigML::Model.new("my_dir/my_model.json")
    local_model.predict({"petal length" => 3, "petal width" => 1})
    Iris-versicolor

If you use a tag to label the resource, you can also ask for the last resource
that has the tag:

.. code-block:: ruby

    api.export_last('my_tag',
                    'my_dir/my_ensemble.json'
                    'ensemble')
                     
and even for a resource inside a project:

.. code-block:: ruby

    api.export_last('my_tag',
                    'my_dir/my_dataset.json'
                    'dataset',
                    'project/5143a51a37203f2cf7000959')


Local Models
------------

You can instantiate a local version of a remote model.

.. code-block:: ruby 

    local_model = BigML::Model.new('model/502fdbff15526876610002615')

This will retrieve the remote model information, using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a Model object
that you can use to make local predictions. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby 

    local_model = BigML::Model.new('model/502fdbff15526876610002615',
                               BigML::Api.new(myusername, my_api_key))

or even use the remote model information retrieved previously to build the
local model object:

.. code-block:: ruby

    api = BigML::Api.new()
    model = api.get_model('model/502fdbff15526876610002615',
                          'only_model=true;limit=-1')

    local_model = BigML::Model.new(model)

Any of these methods will return a Model object that you can use to make
local predictions, generate IF-THEN rules, Tableau rules
or a Python function that implements the model.

Beware of using filtered fields models to instantiate a local model. The local
model methods need the important fields in the ``model`` parameter to be
available. If an important field is missing (because it has been excluded or
filtered), an exception will arise. To avoid that, the last example uses a
particular ``query_string`` parameter that will ensure that the needed
fields information structure is returned in the get call.

You can also build a local model from a model previously retrieved and stored
in a JSON file:

.. code-block:: ruby

    local_model = BigML::Model.new('./my_model.json')

Local Predictions
-----------------

Once you have a local model you can use to generate predictions locally.

.. code-block:: ruby

    local_model.predict({"petal length" => 3, "petal width" => 1})
    petal length > 2.45 AND petal width <= 1.65 AND petal length <= 4.95 =>
    Iris-versicolor

Local predictions have three clear advantages:

- Removing the dependency from BigML to make new predictions.

- No cost (i.e., you do not spend BigML credits).

- Extremely low latency to generate predictions for huge volumes of data.

The default output for local predictions is the prediction itself, but you can
also add other properties associated to the prediction, like its
confidence or probability, the distribution of values in the predicted node
(for decision tree models), and the number of instances supporting the
prediction. To obtain a
dictionary with the prediction and the available additional
properties use the ``'full' => true`` argument:

.. code-block:: ruby

    # add_confidence=true add_path=true
    local_model.predict({"petal length" => 3, "petal width" => 1},
                        {"full" => true})
 
that will return:

.. code-block:: ruby

    {'count': 47,
     'confidence': 0.92444,
     'probability': 0.9861111111111112,
     'prediction': u'Iris-versicolor',
     'distribution_unit': 'categories',
     'path': [u'petal length > 2.45',
              u'petal width <= 1.75',
              u'petal length <= 4.95',
              u'petal width <= 1.65'],
     'distribution': [[u'Iris-versicolor', 47]]}

Note that the ``add_path`` argument for the ``proportional`` missing strategy
shows the path leading to a final unique node, that gives the prediction, or
to the first split where a missing value is found. Other options are
``add_next`` which includes the field that determines the next split after
the prediction node and ``add_distribution`` that adds the distribution
that leads to the prediction. For regression models, ``add_min`` and
``add_max`` will add the limit values for the data that supports the
prediction.

When your test data has missing values, you can choose between ``last
prediction`` or ``proportional`` strategy to compute the
prediction. The ``last prediction`` strategy is the one used by
default. To compute a prediction, the algorithm goes down the model's
decision tree and checks the condition it finds at each node (e.g.:
'sepal length' > 2). If the field checked is missing in your input
data you have two options: by default (``last prediction`` strategy)
the algorithm will stop and issue the last prediction it computed in
the previous node. If you chose ``proportional`` strategy instead, the
algorithm will continue to go down the tree considering both branches
from that node on. Thus, it will store a list of possible predictions
from then on, one per valid node. In this case, the final prediction
will be the majority (for categorical models) or the average (for
regressions) of values predicted by the list of predicted values.

You can set this strategy by using the ``missing_strategy``
argument with code ``0`` to use ``last prediction`` and ``1`` for
``proportional``.

.. code-block:: ruby

    # LAST_PREDICTION = 0; PROPORTIONAL = 1
    local_model.predict({"petal length" => 3, "petal width" => 1},
                        {missing_strategy => BigML::PROPORTIONAL})

For classification models, it is sometimes useful to obtain a
probability or confidence prediction for each possible class of the
objective field.  To do this, you can use the ``predict_probability``
and ``predict_confidence`` methods respectively.  The former gives a
prediction based on the distribution of instances at the appropriate
leaf node, with a Laplace correction based on the root node
distribution.  The latter returns a lower confidence bound on the leaf
node probability based on the Wilson score interval.

Each of these methods take the ``missing_strategy``
argument that functions as it does in ``predict``, and one additional
argument, ``compact``.  If ``compact`` is ``false`` (the default), the
output of these functions is a list of maps, each with the keys
``prediction`` and ``probability`` (or ``confidence``) mapped to the
class name and its associated probability (or confidence). Note that these
methods substitute the deprecated ``multiple`` parameter in the ``predict``
method functionallity.

So, for example, the following:

.. code-block:: ruby

    local_model.predict_probability({"petal length" => 3})

would result in

.. code-block:: ruby

    [{'category' => u'Iris-setosa',
      'probability' => 0.0033003300330033},
     {'category' => u'Iris-versicolor',
      'probability' => 0.4983498349834984},
     {'category' => u'Iris-virginica',
      'probability' => 0.4983498349834984}]

If ``compact`` is ``true``, only the probabilities themselves are
returned, as a list in class name order.  Note that, for reference,
the attribute ``Model.class_names`` contains the class names in the
appropriate ordering.

To illustrate, the following:

.. code-block:: ruby

    local_model.predict_probability({"petal length": 3}, {"missing_strategy" => BigML::LAST_PREDICTION, 
                                                          "compact" => true})

would result in

.. code-block:: ruby

    [0.0033003300330033, 0.4983498349834984, 0.4983498349834984]

The output of ``predict_confidence`` is the same, except that the
output maps are keyed with ``confidence`` instead of ``probability``.


For classifications, the prediction of a local model will be one of the
available categories in the objective field and an associated ``confidence``
or ``probability`` that is used to decide which is the predicted category.
If you prefer the model predictions to be operated using any of them, you can
use the ``operating_kind`` argument in the ``predict`` method.
Here's the example
to use predictions based on ``confidence``:

.. code-block:: ruby

    local_model.predict({"petal length" => 3, "petal width" => 1},
                        {"operating_kind" => "confidence"})

Previous versions of the bindings had additional arguments in the ``predict``
method that were used to format the prediction attributes. The signature of
the method has been changed to accept only arguments that affect the
prediction itself, (like ``missing_strategy``, ``operating_kind`` and
``opreating_point``) and ``full`` which is a boolean that controls whether
the output is the prediction itself or a dictionary will all the available
properties associated to the prediction. Formatting can be achieved by using
the ``cast_prediction`` function:

.. code-block:: ruby

    def cast_prediction(full_prediction, to=nil, confidence=false,
                         probability=false,path=false, distribution=false, 
                         count=false, _next=false, d_min=false, d_max=false, 
                         median=false,unused_fields=false)
                         
whose first argument is the prediction obtained with the ``full=true``
argument, the second one defines the type of output (``None```to obtain
the prediction output only, "list" or "dict") and the rest of booleans
cause the corresponding property to be included or not.

Operating point's predictions
------------------`-----------

In classification problems,
Models, Ensembles and Logistic Regressions can be used at different
operating points, that is, associated to particular thresholds. Each
operating point is then defined by the kind of property you use as threshold,
its value and a the class that is supposed to be predicted if the threshold
is reached.

Let's assume you decide that you have a binary problem, with classes ``true``
and ``false`` as possible outcomes. Imagine you want to be very sure to
predict the `true` outcome, so you don't want to predict that unless the
probability associated to it is over ``0,8``. You can achieve this with any
classification model by creating an operating point:

.. code-block:: ruby

    operating_point = {"kind" => "probability",
                       "positive_class" => "true",
                       "threshold" => 0.8}

to predict using this restriction, you can use the ``operating_point``
parameter:

.. code-block:: ruby

    prediction = local_model.predict(inputData,
                                     {operating_point=>operating_point})

where ``inputData`` should contain the values for which you want to predict.
Local models allow two kinds of operating points: ``probability`` and
``confidence``. For both of them, the threshold can be set to any number
in the ``[0, 1]`` range.


Local Clusters
--------------

You can also instantiate a local version of a remote cluster.

.. code-block:: ruby

    local_cluster = BigML::Cluster.new('cluster/502fdbff15526876610002435')

This will retrieve the remote cluster information, using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``Cluster`` object
that you can use to make local centroid predictions. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_cluster = BigML::Cluster.new('cluster/502fdbff15526876610002435',
                                   BigML::Api.new(my_username,
                                    my_api_key))

or even use the remote cluster information retrieved previously to build the
local cluster object:

.. code-block:: ruby

    api = BigML::Api.new()
    cluster = api.get_cluster('cluster/502fdbff15526876610002435',
                              'limit=-1')

    local_cluster = BigML::Cluster.new(cluster)

Note that in this example we used a ``limit=-1`` query string for the cluster
retrieval. This ensures that all fields are retrieved by the get method in the
same call (unlike in the standard calls where the number of fields returned is
limited).

Local clusters provide also methods for the significant operations that
can be done using clusters: finding the centroid assigned to a certain data
point, sorting centroids according to their distance to a data point,
summarizing
the centroids intra-distances and inter-distances and also finding the
closest points to a given one. The `Local Centroids <#local-centroids>`_
and the
`Summary generation <#summary-generation>`_ sections will
explain these methods.


Local Centroids
---------------

Using the local cluster object, you can predict the centroid associated to
an input data set:

.. code-block:: ruby

    local_cluster.centroid({"pregnancies" => 0, "plasma glucose" => 118,
                            "blood pressure" => 84, "triceps skin thickness" => 47,
                            "insulin" => 230, "bmi" => 45.8,
                            "diabetes pedigree" => 0.551, "age" => 31,
                            "diabetes" => "true"})
    {'distance' => 0.454110207355, 'centroid_name' => 'Cluster 4',
     'centroid_id' => '000004'}


You must keep in mind, though, that to obtain a centroid prediction, input data
must have values for all the numeric fields. No missing values for the numeric
fields are allowed unless you provided a ``default_numeric_value`` in the
cluster construction configuration. If so, this value will be used to fill
the missing numeric fields.

As in the local model predictions, producing local centroids can be done
independently of BigML servers, so no cost or connection latencies are
involved.

Another interesting method in the cluster object is
``local_cluster.closests_in_cluster``, which given a reference data point
will provide the rest of points that fall into the same cluster sorted
in an ascending order according to their distance to this point. You can limit
the maximum number of points returned by setting the ``number_of_points``
argument to any positive integer.

.. code-block:: ruby

    local_cluster.closests_in_cluster(
        {"pregnancies" => 0, "plasma glucose" => 118,
         "blood pressure" => 84, "triceps skin thickness" => 47,
         "insulin" => 230, "bmi"=> 45.8,
         "diabetes pedigree"=> 0.551, "age"=> 31,
         "diabetes" =>"true"}, 2)

The response will be a dictionary with the centroid id of the cluster an
the list of closest points and their distances to the reference point.

.. code-block:: ruby

    {'closest': [ \
        {'distance': 0.06912270988567025,
         'data': {'plasma glucose': '115', 'blood pressure': '70',
                  'triceps skin thickness': '30', 'pregnancies': '1',
                  'bmi': '34.6', 'diabetes pedigree': '0.529',
                  'insulin': '96', 'age': '32', 'diabetes': 'true'}},
        {'distance': 0.10396456577958413,
         'data': {'plasma glucose': '167', 'blood pressure': '74',
         'triceps skin thickness': '17', 'pregnancies': '1', 'bmi': '23.4',
         'diabetes pedigree': '0.447', 'insulin': '144', 'age': '33',
         'diabetes': 'true'}}],
    'reference': {'age': 31, 'bmi': 45.8, 'plasma glucose': 118,
                  'insulin': 230, 'blood pressure': 84,
                  'pregnancies': 0, 'triceps skin thickness': 47,
                  'diabetes pedigree': 0.551, 'diabetes': 'true'},
    'centroid_id': u'000000'}

No missing numeric values are allowed either in the reference data point.
If you want the data points to belong to a different cluster, you can
provide the ``centroid_id`` for the cluster as an additional argument.

Other utility methods are ``local_cluster.sorted_centroids`` which given
a reference data point will provide the list of centroids sorted according
to the distance to it

.. code-block:: ruby

    local_cluster.sorted_centroids( \
    {'plasma glucose' => '115', 'blood pressure' => '70',
     'triceps skin thickness' => '30', 'pregnancies' => '1',
     'bmi' => '34.6', 'diabetes pedigree' => '0.529',
     'insulin' => '96', 'age' => '32', 'diabetes' => 'true'})
    {'centroids' => [{'distance' => 0.31656890408929705,
                    'data': {'000006' => 0.34571, '000007' => 30.7619,
                             '000000' => 3.79592, '000008' => u'false'},
                    'centroid_id' => '000000'},
                   {'distance' => 0.4424198506958207,
                    'data': {'000006' => 0.77087, '000007' => 45.50943,
                             '000000' => 5.90566, '000008' => u'true'},
                    'centroid_id' => '000001'}],
     'reference': {'age' => '32', 'bmi' => '34.6', 'plasma glucose' => '115',
                   'insulin' => '96', 'blood pressure' => '70',
                   'pregnancies' => '1', 'triceps skin thickness' => '30',
                   'diabetes pedigree' => '0.529', 'diabetes' => 'true'}}



or ``points_in_cluster`` that returns the list of
data points assigned to a certain cluster, given its ``centroid_id``.

.. code-block:: ruby

    centroid_id = "000000"
    local_cluster.points_in_cluster(centroid_id)

Local Anomaly Detector
----------------------

You can also instantiate a local version of a remote anomaly.

.. code-block:: ruby

    local_anomaly = BigML::Anomaly('anomaly/502fcbff15526876610002435')

This will retrieve the remote anomaly detector information, using an implicitly
built ``BigML()`` connection object (see the ``Authentication`` section for
more details on how to set your credentials) and return an ``Anomaly`` object
that you can use to make local anomaly scores. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_anomaly = BigML::Anomaly.new('anomaly/502fcbff15526876610002435',
                                    BigML::Api.new(my_username,
                                      my_api_key))

or even use the remote anomaly information retrieved previously to build the
local anomaly detector object:

.. code-block:: ruby

    api = BigML::Api.new()
    anomaly = api.get_anomaly('anomaly/502fcbff15526876610002435',
                              'limit=-1')

    local_anomaly = BigML::Anomaly.new(anomaly)

Note that in this example we used a ``limit=-1`` query string for the anomaly
retrieval. This ensures that all fields are retrieved by the get method in the
same call (unlike in the standard calls where the number of fields returned is
limited).

The anomaly detector object has also the method ``anomalies_filter``
that will build the LISP filter you would need to filter the original
dataset and create a new one excluding
the top anomalies. Setting the ``include`` parameter to true you can do the
inverse and create a dataset with only the most anomalous data points.


ocal Anomaly Scores
--------------------

Using the local anomaly detector object, you can predict the anomaly score
associated to an input data set:

.. code-block:: ruby

    local_anomaly.anomaly_score({"src_bytes" => 350})
    0.9268527808726705


As in the local model predictions, producing local anomaly scores can be done
independently of BigML servers, so no cost or connection latencies are
involved.

Local Logistic Regression
-------------------------

You can also instantiate a local version of a remote logistic regression.

.. code-block:: ruby

    local_log_regression = BigML::Logistic.new(
        'logisticregression/502fdbff15526876610042435')

This will retrieve the remote logistic regression information,
using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``LogisticRegression``
object that you can use to make local predictions. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_log_regression = BigML::Logistic.new(
        'logisticregression/502fdbff15526876610602435',
        BigML::Api.new(my_username, my_api_key))

You can also reuse a remote logistic regression JSON structure
as retrieved previously to build the
local logistic regression object:

.. code-block:: ruby

    api = BigML::Api.new
    logistic_regression = api.get_logisticregression(
        'logisticregression/502fdbff15526876610002435',
        'limit=-1')

    local_log_regression = BigML::Logistic.new(logistic_regression)

Note that in this example we used a ``limit=-1`` query string for the logistic
regression retrieval. This ensures that all fields are retrieved by the get
method in the
same call (unlike in the standard calls where the number of fields returned is
limited).


Local Logistic Regression Predictions
-------------------------------------

Using the local logistic regression object, you can predict the prediction for
an input data set:

.. code-block:: ruby

    local_log_regression.predict({"petal length" => 2, "sepal length" => 1.5,
                                  "petal width" => 0.5, "sepal width" => 0.7})
    {'distribution' => [
        {'category' => 'Iris-virginica', 'probability' => 0.5041444478857267},
        {'category' => 'Iris-versicolor', 'probability' => 0.46926542042788333},
        {'category' => 'Iris-setosa', 'probability' => 0.02659013168639014}],
        'prediction' => u'Iris-virginica', 'probability' => 0.5041444478857267}

As you can see, the prediction contains the predicted category and the
associated probability. It also shows the distribution of probabilities for
all the possible categories in the objective field.

You must keep in mind, though, that to obtain a logistic regression
prediction, input data
must have values for all the numeric fields. No missing values for the numeric
fields are allowed.

For consistency of interface with the ``Model`` class, logistic
regressions again have a ``predict_probability`` method, which takes
the same argument as ``Model.predict``:
``compact``.  As stated above, missing values are not allowed, and so
there is no ``missing_strategy`` argument.

As with local Models, if ``compact`` is ``false`` (the default), the
output is a list of maps, each with the keys ``prediction`` and
``probability`` mapped to the class name and its associated
probability.

So, for example

.. code-block:: ruby

    local_log_regression.predict_probability({"petal length" => 2, "sepal length" => 1.5,
                                              "petal width" => 0.5, "sepal width" => 0.7})

    [{'category' => u'Iris-setosa', 'probability' => 0.02659013168639014},
     {'category' => u'Iris-versicolor', 'probability' => 0.46926542042788333},
     {'category' => u'Iris-virginica', 'probability' => 0.5041444478857267}]

If ``compact`` is ``true``, only the probabilities themselves are
returned, as a list in class name order, again, as is the case with
local Models.

Operating point predictions are also available for local logistic regressions
and an example of it would be:

.. code-block:: ruby

    operating_point = {"kind" => "probability",
                       "positive_class" => "true",
                       "threshold" => 0.8}
    local_logistic.predict(inputData, {operating_point => operating_point})


You can check the
`Operating point's predictions <#operating-point's-predictions>`_ section
to learn about
operating points. For logistic regressions, the only available kind is
``probability``, that sets the threshold of probability to be reached for the
prediction to be the positive class.


Local Deepnet
-------------

You can also instantiate a local version of a remote Deepnet.

.. code-block:: ruby

    local_deepnet = BigML::Deepnet.new(
        'deepnet/502fdbff15526876610022435')

This will retrieve the remote deepnet information,
using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``Deepnet``
object that you can use to make local predictions. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_deepnet = Deepnet(
        'deepnet/502fdbff15526876610602435',
        api=BigML::Api.new(my_username, my_api_key))

You can also reuse a remote Deepnet JSON structure
as previously retrieved to build the
local Deepnet object:

.. code-block:: ruby

    api = BigML::Api.new()
    deepnet = api.get_deepnet(
        'deepnet/502fdbff15526876610002435',
        'limit=-1')

    local_deepnet = BigML::Deepnet.new(deepnet)

Note that in this example we used a ``limit=-1`` query string for the
deepnet retrieval. This ensures that all fields are
retrieved by the get method in the same call (unlike in the standard
calls where the number of fields returned is limited).

Local Deepnet Predictions
-------------------------

Using the local deepnet object, you can predict the prediction for
an input data set:

.. code-block:: ruby

    local_deepnet.predict({"petal length" => 2, "sepal length" => 1.5,
                           "petal width" => 0.5, "sepal width" => 0.7},
                           {"full" => true})
    {'distribution' => [
        {'category' => u'Iris-virginica', 'probability' => 0.5041444478857267},
        {'category' => u'Iris-versicolor', 'probability' => 0.46926542042788333},
        {'category' => u'Iris-setosa', 'probability' => 0.02659013168639014}],
        'prediction' => u'Iris-virginica', 'probability' => 0.5041444478857267}

As you can see, the full prediction contains the predicted category and the
associated probability. It also shows the distribution of probabilities for
all the possible categories in the objective field. If you only need the
predicted value, you can remove the ``full`` argument.

To be consistent with the ``Model`` class interface, deepnets
have also a ``predict_probability`` method, which takes
the same argument as ``Model.predict``:
``compact``.

As with local Models, if ``compact`` is ``false`` (the default), the
output is a list of maps, each with the keys ``prediction`` and
``probability`` mapped to the class name and its associated
probability.

So, for example

.. code-block:: ruby

    local_deepnet.predict_probability({"petal length" => 2, "sepal length" => 1.5,
                                       "petal width" => 0.5, "sepal width" => 0.7})

    [{'prediction' => 'Iris-setosa', 'probability' => 0.02659013168639014},
     {'prediction' => 'Iris-versicolor', 'probability' => 0.46926542042788333},
     {'prediction' => 'Iris-virginica', 'probability' => 0.5041444478857267}]

If ``compact`` is ``true``, only the probabilities themselves are
returned, as a list in class name order, again, as is the case with
local Models.

Operating point predictions are also available for local deepnets and an
example of it would be:

.. code-block:: ruby

    operating_point = {"kind" => "probability",
                       "positive_class" => "true",
                       "threshold" => 0.8}
    prediction = local_deepnet.predict(inputData,
                                       {"operating_point" => operating_point})


Local Fusion
------------

You can also instantiate a local version of a remote Fusion.

.. code-block:: ruby

    local_fusion = BigML::Fusion.new('fusion/502fdbff15526876610022438')

This will retrieve the remote fusion information,
using an implicitly built
``BigML::Api()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``Fusion``
object that you can use to make local predictions. If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_fusion = BigML::Fusion.new(
        'fusion/502fdbff15526876610602435',
        BigML::Api.new(my_username, my_api_key))

You can also reuse a remote Fusion JSON structure
as previously retrieved to build the
local Fusion object:

.. code-block:: ruby

    api = BigML::Api.new()
    fusion = api.get_fusion(
        'fusion/502fdbff15526876610002435',
        'limit=-1')

    local_fusion = BigML::Fusion.new(fusion)

Note that in this example we used a ``limit=-1`` query string for the
fusion retrieval. This ensures that all fields are
retrieved by the get method in the same call (unlike in the standard
calls where the number of fields returned is limited).

Local Fusion Predictions
-------------------------

Using the local fusion object, you can predict the prediction for
an input data set:

.. code-block:: ruby

    local_fusion.predict({"petal length" => 2, "sepal length" => 1.5,
                          "petal width" => 0.5, "sepal width" => 0.7},
                          {"full" => true})
    {'prediction' => u'Iris-setosa', 'probability' => 0.45224}


As you can see, the full prediction contains the predicted category and the
associated probability. If you only need the
predicted value, you can remove the ``full`` argument.

To be consistent with the ``Model`` class interface, fusions
have also a ``predict_probability`` method, which takes
the same argument as ``Model.predict``:
``compact``.

As with local Models, if ``compact`` is ``false`` (the default), the
output is a list of maps, each with the keys ``prediction`` and
``probability`` mapped to the class name and its associated
probability.

So, for example

.. code-block:: ruby

    local_fusion.predict_probability({"petal length" => 2, "sepal length" => 1.5,
                                      "petal width" => 0.5, "sepal width" => 0.7})

    [{'category' => u'Iris-setosa', 'probability' => 0.45224},
     {'category' => u'Iris-versicolor', 'probability' => 0.2854},
     {'category' => u'Iris-virginica', 'probability' => 0.26236}]


If ``compact`` is ``true``, only the probabilities themselves are
returned, as a list in class name order, again, as is the case with
local Models.

Operating point predictions are also available with probability as threshold
for local fusions and an
example of it would be:

.. code-block:: ruby

    operating_point = {"kind" => "probability",
                       "positive_class" => "true",
                       "threshold" => 0.8}
    prediction = local_fusion.predict(inputData,
                                      {"operating_point" => operating_point})


Local Association
-----------------


You can also instantiate a local version of a remote association resource.

.. code-block:: ruby

    local_association = BigML::Association.new('association/502fdcff15526876610002435')

This will retrieve the remote association information, using an implicitly
built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return an ``Association`` object
that you can use to extract the rules found in the original dataset.
If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_association = BigML::Association.new('association/502fdcff15526876610002435',
                                              BigML::Api.new(my_username,
                                              my_api_key))

or even use the remote association information retrieved previously
to build the
local association object:

.. code-block:: ruby

    api = BigML::Api.new
    association = api.get_association('association/502fdcff15526876610002435',
                                      'limit=-1')

    local_association = BigML::Association.new(association)

Note that in this example we used a ``limit=-1`` query string for the
association retrieval. This ensures that all fields are retrieved by the get
method in the
same call (unlike in the standard calls where the number of fields returned is
limited).

The created ``Association`` object has some methods to help retrieving the
association rules found in the original data. The ``get_rules`` method will
return the association rules. Arguments can be set to filter the rules
returned according to its ``leverage``, ``strength``, ``support``, ``p_value``,
a list of items involved in the rule or a user-given filter function.

.. code-block:: ruby

    local_association = BigML::Association.new('association/502fdcff15526876610002435')
    # item_list=["Edible"], min_p_value=0.3
    local_association.get_rules(nil, nil, nil, 0.3,["Edible"])


In this example, the only rules that will be returned by the ``get_rules``
method will be the ones that mention ``Edible`` and their ``p_value``
is greater or equal to ``0.3``.

The rules can also be stored in a CSV file using ``rules_csv``:


.. code-block:: ruby

    local_association = BigML::Association.new('association/502fdcff15526876610002435')
    local_association.rules_csv('./tmp/my_rules.csv',
                               {'min_strength' => 0.1})

This example will store the rules whose strength is bigger or equal to 0.1 in
the ``./tmp/my_rules.csv`` file.

You can also obtain the list of ``items`` parsed in the dataset using the
``get_items`` method. You can also filter the results by field name, by
item names and by a user-given function:

.. code-block:: ruby

    local_association = BigML::Association.new('association/502fdcff15526876610002435')
    # field="Cap Color", names=["Brown cap", "White cap", "Yellow cap"]
    local_association.get_items("Cap Color",
                                ["Brown cap", "White cap", "Yellow cap"])


This will recover the ``Item`` objects found in the ``Cap Color`` field for
the names in the list, with their properties as described in the
`developers section <https://bigml.com/developers/associations#ad_retrieving_an_association>`_


Local Association Sets
----------------------

Using the local association object, you can predict the association sets
related to an input data set:

.. code-block:: ruby

    local_association.association_set( \
        {"gender" => "Female", "genres" => "Adventure$Action", \
         "timestamp" => 993906291, "occupation" => "K-12 student",
         "zipcode" => 59583, "rating" => 3})
    [{'item' => {'bin_end' => nil,
               'bin_start'=> nie,
               'complement' => false,
               'count' => 70,
               'description' => nil,
               'field_id' => u'000002',
               'name' => u'Under 18'},
      'score' => 0.0969181441561211},
     {'item' =>  {'bin_end' =>  nil,
               'bin_start' =>  nil,
               'complement' =>  false,
               'count' =>  216,
               'description' =>  nil,
               'field_id' =>  u'000007',
               'name' =>  u'Drama'},
      'score' =>  0.025050115102862636},
     {'item' =>  {'bin_end' =>  nil,
               'bin_start' =>  nil,
               'complement' =>  false,
               'count' =>  108,
               'description' =>  nil,
               'field_id' =>  u'000007',
               'name' =>  u'Sci-Fi'},
      'score' =>  0.02384578264599424},
     {'item' =>  {'bin_end' =>  nil,
               'bin_start' =>  nil,
               'complement' =>  false,
               'count' =>  40,
               'description' =>  nil,
               'field_id' =>  u'000002',
               'name' =>  u'56+'},
      'score' =>  0.021845366022721312},
     {'item' =>  {'bin_end' =>  nil,
               'bin_start' =>  nil,
               'complement' =>  false,
               'count' =>  66,
               'description' =>  nil,
               'field_id' =>  u'000002',
               'name' =>  u'45-49'},
      'score' =>  0.019657155185835006}]

As in the local model predictions, producing local association sets can be done
independently of BigML servers, so no cost or connection latencies are
involved.


Local Topic Model
-----------------

You can also instantiate a local version of a remote topic model.

.. code-block:: ruby

    local_topic_model = BigML::TopicModel.new(
        'topicmodel/502fdbcf15526876210042435')

This will retrieve the remote topic model information,
using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``TopicModel``
object that you can use to obtain local topic distributions.
If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_topic_model = BigML::TopicModel.new(
        'topicmodel/502fdbcf15526876210042435',
        api=BigML::Api.new(my_username, my_api_key))

You can also reuse a remote topic model JSON structure
as previously retrieved to build the
local topic model object:

.. code-block:: ruby

    api = BigML::Api::new()
    topic_model = api.get_topic_model(
        'topicmodel/502fdbcf15526876210042435',
         'limit=-1')

    local_topic_model = BigML::TopicModel.new(topic_model)

Note that in this example we used a ``limit=-1`` query string for the topic
model retrieval. This ensures that all fields are retrieved by the get
method in the
same call (unlike in the standard calls where the number of fields returned is
limited).


Local Topic Distributions
-------------------------

Using the local topic model object, you can predict the local topic
distribution for
an input data set:

.. code-block:: ruby

    local_topic_model.distribution({"Message"=> "Our mobile phone is free"})
    [   {   'name'=> u'Topic 00', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 01', 'probability'=> 0.003257671290458176},
        {   'name'=> u'Topic 02', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 03', 'probability'=> 0.1968263976460698},
        {   'name'=> u'Topic 04', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 05', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 06', 'probability'=> 0.13692728036990331},
        {   'name'=> u'Topic 07', 'probability'=> 0.6419714165615805},
        {   'name'=> u'Topic 08', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 09', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 10', 'probability'=> 0.002627154266498529},
        {   'name'=> u'Topic 11', 'probability'=> 0.002627154266498529}]


As you can see, the topic distribution contains the name of the
possible topics in the model and the
associated probabilities.

Local Time Series
-----------------

You can also instantiate a local version of a remote time series.

.. code-block:: ruby

    local_time_series = BigML::TimeSeries.new(
        'timeseries/502fdbcf15526876210042435')

This will create a series of models from
the remote time series information,
using an implicitly built
``BigML()`` connection object (see the ``Authentication`` section for more
details on how to set your credentials) and return a ``TimeSeries``
object that you can use to obtain local forecasts.
If you want to use a
specfic connection object for the remote retrieval, you can set it as second
parameter:

.. code-block:: ruby

    local_time_series = BigML::TimeSeries.new( \
        'timeseries/502fdbcf15526876210042435',
         BigML::Api.new(my_username, my_api_key))

You can also reuse a remote time series JSON structure
as previously retrieved to build the
local time series object:

.. code-block:: ruby

    api = BigML::Api.new()
    time_series = api.get_time_series(
        'timeseries/502fdbcf15526876210042435',
         'limit=-1')

    local_time_series = BigML::TimeSeries.new(time_series)

Note that in this example we used a ``limit=-1`` query string for the topic
model retrieval. This ensures that all fields are retrieved by the get
method in the
same call (unlike in the standard calls where the number of fields returned is
limited).


Local Forecasts
---------------

Using the local time series object, you can forecast any of the objective
field values:

.. code-block:: ruby

    local_time_series.forecast({"Final"=> {"horizon"=> 5}, "Assignment"=> {
        "horizon"=> 10, "ets_models"=> {"criterion"=> "aic", "limit"=> 2}}})
    {u'000005'=> [
        {'point_forecast'=> [68.53181, 68.53181, 68.53181, 68.53181, 68.53181],
         'model'=> u'A,N,N'}],
     u'000001'=> [{'point_forecast'=> [54.776650000000004, 90.00943000000001,
                                     83.59285000000001, 85.72403000000001,
                                     72.87196, 93.85872, 84.80786, 84.65522,
                                     92.52545, 88.78403],
                  'model'=> u'A,N,A'},
                 {'point_forecast'=> [55.882820120000005, 90.5255466567616,
                                     83.44908577909621, 87.64524353046498,
                                     74.32914583152592, 95.12372848262932,
                                     86.69298716626228, 85.31630744944385,
                                     93.62385478607113, 89.06905451921818],
                  'model'=> u'A,Ad,A'}]}


As you can see, the forecast contains the ID of the forecasted field, the
computed points and the name of the models meeting the criterion.
For more details about the available parameters, please check the `API
documentation <https://bigml.com/api/forecasts>`_.

Multi Models
------------

Multi Models use a numbers of BigML remote models to build a local version
that can be used to generate predictions locally. Predictions are generated
combining the outputs of each model.

.. code-block:: ruby

    api = BigML::Api.new

    models = api.list_models("tags__in=my_ta")["objects"]
    model = BigML::Api.MultiModel(models.collect{| m| m["resource"]})

    model.predict({"petal length" => 3, "petal width" => 1})

This will create a multi model using all the models that have been previously
tagged with ``my_tag`` and predict by combining each model's prediction.
The combination method used by default is ``plurality`` for categorical
predictions and mean value for numerical ones. You can also use ``confidence
weighted``:

.. code-block:: ruby

    # method=1
    model.predict({"petal length" => 3, "petal width" => 1}, {'method' => 1})

that will weight each vote using the confidence/error given by the model
to each prediction, or even ``probability weighted``:

.. code-block:: ruby
    # method = 2
    model.predict({"petal length" => 3, "petal width" => 1}, {'method' => 2})

that weights each vote by using the probability associated to the training
distribution at the prediction node.

There's also a ``threshold`` method that uses an additional set of options:
threshold and category. The category is predicted if and only if
the number of predictions for that category is at least the threshold value.
Otherwise, the prediction is plurality for the rest of predicted values.

An example of ``threshold`` combination method would be:

.. code-block:: ruby

    # method = 3, options = {'threshold' => 3, 'category' => 'Iris-virginica'}
    model.predict({'petal length' => 0.9, 'petal width' => 3.0},
                  {'method' => 3, 
                   'options' => {'threshold' => 3, 'category' => 'Iris-virginica'}})


When making predictions on a test set with a large number of models,
``batch_predict`` can be useful to log each model's predictions in a
separated file. It expects a list of input data values and the directory path
to save the prediction files in.

.. code-block:: ruby

    model.batch_predict([{"petal length" => 3, "petal width" => 1},
                         {"petal length" => 1, "petal width" => 5.1}],
                        "data/predictions")

The predictions generated for each model will be stored in an output
file in `data/predictions` using the syntax
`model_[id of the model]__predictions.csv`. For instance, when using
`model/50c0de043b563519830001c2` to predict, the output file name will be
`model_50c0de043b563519830001c2__predictions.csv`. An additional feature is
that using ``reuse=true`` as argument will force the function to skip the
creation of the file if it already exists. This can be
helpful when using repeatedly a bunch of models on the same test set.

.. code-block:: ruby 
    # reuse = true
    model.batch_predict([{"petal length" => 3, "petal width" => 1},
                         {"petal length" => 1, "petal width" => 5.1}],
                        "data/predictions", true, true)

Prediction files can be subsequently retrieved and converted into a votes list
using ``batch_votes``:

.. code-block:: ruby

    model.batch_votes("data/predictions")

which will return a list of MultiVote objects. Each MultiVote contains a list
of predictions (e.g. ``[{'prediction' => u'Iris-versicolor', 'confidence' => 0.34,
'order' => 0}, {'prediction' => u'Iris-setosa', 'confidence' => 0.25,
'order' => 1}]``).
These votes can be further combined to issue a final
prediction for each input data element using the method ``combine``

.. code-block:: ruby

    model.batch_votes("data/predictions").each do | multivote|
        prediction = multivote.combine()
    end

Again, the default method of combination is ``plurality`` for categorical
predictions and mean value for numerical ones. You can also use ``confidence
weighted``:

.. code-block:: ruby

    prediction = multivote.combine(1)

or ``probability weighted``:

.. code-block:: ruby

    prediction = multivote.combine(2)

You can also get a confidence measure for the combined prediction:

.. code-block:: ruby

    prediction = multivote.combine(0,true)

For classification, the confidence associated to the combined prediction
is derived by first selecting the model's predictions that voted for the
resulting prediction and computing the weighted average of their individual
confidence. Nevertheless, when ``probability weighted`` is used,
the confidence is obtained by using each model's distribution at the
prediction node to build a probability distribution and combining them.
The confidence is then computed as the wilson score interval of the
combined distribution (using as total number of instances the sum of all
the model's distributions original instances at the prediction node)

In regression, all the models predictions' confidences contribute
to the weighted average confidence.

Local Ensembles
---------------

Remote ensembles can also be used locally through the ``Ensemble``
class. The simplest way to access an existing ensemble and using it to
predict locally is:

.. code-block:: ruby

    ensemble = BigML::Ensemble.new('ensemble/5143a51a37203f2cf7020351')
    ensemble.predict({"petal length" => 3, "petal width" => 1})

This call will download all the ensemble related info and store it in a
``./storage`` directory ready to be used to predict. As in
``MultipleModel``, several prediction combination methods are available, and
you can choose another storage directory or even avoid storing at all, for
instance:

.. code-block:: ruby

    # api connection with storage 'my_storage'
    api = BigML::Api.new(nil,nil, false, false, false,'./my_storage')

    # creating ensemble
    ensemble = api.create_ensemble('dataset/5143a51a37203f2cf7000972')

    # Ensemble object to predict
    ensemble = BigML::Ensemble.new(ensemble, api)
    # predict with method = 1
    ensemble.predict({"petal length" => 3, "petal width" => 1}, {'method' => 1})

creates a new ensemble and stores its information in ``./my_storage``
folder. Then this information is used to predict locally using the
``confidence weighted`` method.

Similarly, local ensembles can also be created by giving a list of models to be
combined to issue the final prediction:

.. code-block:: ruby 

    ensemble = Ensemble(['model/50c0de043b563519830001c2',
                         'model/50c0de043b5635198300031b')]
    ensemble.predict({"petal length" => 3, "petal width" => 1})

or even a JSON file that contains the ensemble resource:

.. code-block:: ruby

    api = BigML::Api.new()
    ensemble_info = api.get_ensemble('ensemble/50c0de043b5635198300033c')
  
    File.open('./my_ensemble', 'w') do | f|
      f.puts JSON.genarate(ensemble_info)
    end    

    local_ensemble = BigML::Ensemble.new("./my_ensemble")

Note: the ensemble JSON structure is not self-contained, meaning that it
contains references to the models that the ensemble is build of, but not the
information of the models themselves.
To use an ensemble locally with no connection to
the internet, you must make sure that not only a local copy of the ensemble
JSON file is available in your computer, but also the JSON files corresponding
to the models in it. This is automatically achieved when you use the
``Ensemble('ensemble/50c0de043b5635198300033c')`` constructor, that fetches
all the related JSON files and stores them in an ``./storage`` directory. Next
calls to ``Ensemble('ensemble/50c0de043b5635198300033c')`` will retrieve the
files from this local storage, so that internet connection will only be needed
the first time an ``Ensemble`` is built.

On the contrary, if you have no memory limitations and want to increase
prediction speed, you can create the ensemble from a list of local model
objects. Then, local model objects will only be instantiated once, and
this could increase performance for large ensembles:

.. code-block:: ruby

    model_ids = ['model/50c0de043b563519830001c2',
                 'model/50c0de043b5635198300031b')]
    local_models = model_ids.collect{| model_id| BigML::Model.new(model_id)}
    local_ensemble = BigML::Ensemble.new(local_models)

The ``Ensemble`` object can also be instantiated using local models previously
stored in disks or memory object caching systems. To retrieve these models
provide a list of model ids as first argument and an extra argument
named ``cache_get`` that should be a function receiving the model id
to be retrieved and returning a local model object.

.. code-block:: ruby

    model_ids = ['model/50c0de043b563519830001c2',
                 'model/50c0de043b5635198300031b')]

    cache_get = Proc.new do|model_id|
       # Retrieves a JSON model structure and builds a local model object
       model_file = model_id.gsub("/", "_")
       BigML::Model.new(JSON.parse(File.open(model_file, 'r').read))
    end

    # cache_get=cache_get
    local_ensemble = BigML::Ensemble.new(model_ids, nil, nil, cache_get)
    

Local Ensemble's Predictions
----------------------------

As in the local model's case, you can use the local ensemble to create
new predictions for your test data, and set some arguments to configure
the final output of the ``predict`` method.

The predictions' structure will vary depending on the kind of
ensemble used. For ``Decision Forests`` local predictions will just contain
the ensemble's final prediction if no other argument is used.

.. code-block:: ruby

    ensemble = BigML::Ensemble.new('ensemble/5143a51a37203f2cf7020351')
    ensemble.predict({"petal length" => 3, "petal width" => 1})
    'Iris-versicolor'

The final prediction of an ensemble is determined
by aggregating or selecting the predictions of the individual models therein.
For classifications, the most probable class is returned if no especial
operating method is set. Using ``'full' => true`` you can see both the predicted
output and the associated probability:

.. code-block:: ruby

    ensemble = BigML::Ensemble.new('ensemble/5143a51a37203f2cf7020351')
    ensemble.predict({"petal length" => 3, "petal width" => 1}, \
                     {"full" => true})

    {'prediction' => u'Iris-versicolor',
     'probability' => 0.98566}

In general, the prediction in a classification
will be one amongst the list of categories in the objective
field. When each model in the ensemble
is used to predict, each category has a confidence, a
probability or a vote associated to this prediction.
Then, through the collection
of models in the
ensemble, each category gets an averaged confidence, probabiity and number of
votes. Thus you can decide whether to operate the ensemble using the
``confidence``, the ``probability`` or the ``votes`` so that the predicted
category is the one that scores higher in any of these quantities. The
criteria can be set using the `operating_kind` option (default is set to
``probability``):

.. code-block:: ruby

    ensemble.predict({"petal length" => 3, "petal width" => 1}, \
                     {"operating_kind" => "votes"})

Regression will generate a predictiona and an associated error, however
``Boosted Trees`` don't have an associated confidence measure, so
only the prediction will be obtained in this case.

For consistency of interface with the ``Model`` class, as well as
between boosted and non-boosted ensembles, local Ensembles again have
a ``predict_probability`` method.  This takes the same optional
arguments as ``Model.predict``: ``missing_strategy`` and
``compact``. As with local Models, if ``compact`` is ``false`` (the default),
the output is a list of maps, each with the keys ``prediction`` and
``probability`` mapped to the class name and its associated
probability.

So, for example:

.. code-block:: ruby

    ensemble.predict_probability({"petal length" => 3, "petal width" => 1})

    [{'category' => 'Iris-setosa', 'probability' => 0.006733220044732548},
     {'category' => 'Iris-versicolor', 'probability' => 0.9824478534614787},
     {'category' => 'Iris-virginica', 'probability' => 0.0108189264937886}]

If ``compact`` is ``true``, only the probabilities themselves are
returned, as a list in class name order, again, as is the case with
local Models.

Operating point predictions are also available for local ensembles and an
example of it would be:

.. code-block:: ruby

    operating_point = {"kind" => "probability",
                       "positive_class" => "true",
                       "threshold" => 0.8};
    prediction = local_ensemble.predict(inputData,
                                        {"operating_point" => operating_point})

You can check the
`Operating point's predictions <#operating-point's-predictions>`_ section
to learn about
operating points. For ensembles, three kinds of operating points are available:
``votes``, ``probability`` and ``confidence``. ``Votes`` will use as threshold
the number of models in the ensemble that vote for the positive class.
The other two are already explained in the above mentioned section.


Local Supervised Model
----------------------

There's a general class that will allow you to predict using any supervised
model resource, regardless of its particular type (model, ensemble,
logistic regression or deepnet).

The ``SupervisedModel`` object will retrieve the resource information and
instantiate the corresponding local object, so that you can use its
``predict`` method to produce local predictions:

.. code-block:: ruby

    local_supervised_1 = BigML::SupervisedModel.new( \
        "logisticregression/5143a51a37203f2cf7020351")
    local_supervised_2 =  BigML::SupervisedModel.new( \
        "model/5143a51a37203f2cf7020351")
    input_data = {"petal length" => 3, "petal width" => 1}
    logistic_regression_prediction = local_supervised_1.predict(input_data)
    model_prediction = local_supervised_2.predict(input_data)

Fields
------

Once you have a resource, you can use the ``Fields`` class to generate a
representation that will allow you to easily list fields, get fields ids, get a
field id by name, column number, etc.

.. code-block:: ruby

    api = BigML::Api.new
    source = api.get_source("source/5143a51a37203f2cf7000974")

    fields = BigML::Fields.new(source)

you can also instantiate the Fields object from the fields dict itself:

.. code-block:: ruby

    api = BigML::Api.new
    source = api.get_source("source/5143a51a37203f2cf7000974")

    fields = BigML::Fields.new(source['object']['fields'])

The newly instantiated Fields object will give direct methods to retrieve
different fields properties:

.. code-block:: ruby

    # Internal id of the 'sepal length' field
    fields.field_id('sepal length')

    # Field name of field with column number 0
    fields.field_name(0)

    # Column number of field name 'petal length'
    fields.field_column_number('petal length')

    # Statistics of values in field name 'petal length')
    fields.stats('petal length')

Depending on the resource type, Fields information will vary. ``Sources`` will
have only the name, label, description, type of field (``optype``) while
``dataset`` resources will have also the ``preferred`` (whether a field will is
selectable as predictor), ``missing_count``, ``errors`` and a summary of
the values found in each field. This is due to the fact that the ``source``
object is built by inspecting the contents of a sample of the uploaded file,
while the ``dataset`` resource really reads all the uploaded information. Thus,
dataset's fields structure will always be more complete that source's.

In both cases, you can extract the summarized information available using
the ``summary_csv`` method:

.. code-block:: ruby 

    api = BigML::Api.new
    dataset = api.get_dataset("dataset/5143a51a37203f2cf7300974")

    fields = BigML::Fields.new(dataset)
    fields.summary_csv("my_fields_summary.csv")

In this example, the information will be stored in the
``my_fields_summary.csv`` file. For the typical ``iris.csv`` data file, the
summary will read:

.. csv-table::
   :header: "field column","field ID","field name","field label","field description","field type","preferred","missing count","errors","contents summary","errors summary"
   :widths: 5, 10, 20, 5, 5, 10, 10, 5, 5, 100, 10

   0,000000,sepal length,,,numeric,true,0,0,"[4.3, 7.9], mean: 5.84333",
   1,000001,sepal width,,,numeric,false,0,0,"[2, 4.4], mean: 3.05733",
   2,000002,petal length,,,numeric,true,0,0,"[1, 6.9], mean: 3.758",
   3,000003,petal width,,,numeric,true,0,0,"[0.1, 2.5], mean: 1.19933",
   4,000004,species,,,categorical,true,0,0,"3 categorìes: Iris-setosa (50), Iris-versicolor (50), Iris-virginica (50)",

Another utility in the ``Fields`` object will help you update the updatable
attributes of your source or dataset fields. For instance, if you
need to update the type associated to one field in your dataset,
you can change the ``field type``
values in the previous file and use it to obtain the fields structure
needed to update your source:

.. code-block:: ruby

    api = BigML::Api.new()
    source = api.get_source("source/5143a51a37203f2cf7000974")

    fields = BigML::Fields.new(source)
    fields_update_info = fields.new_fields_structure("my_fields_summary.csv")
    source = api.update_source(source, fields_update_info)

For both sources and datasets, the updatable attributes are name, label and
description. In ``sources`` you can also update the type of the field, and
in ``datasets`` you can update the ``preferred`` attribute.

In addition to that, you can also easily ``pair`` a list of values with fields
ids what is very
useful to make predictions.

For example, the following snippet may be useful to create local predictions
using a csv file as input:

.. code-block:: ruby

    test_reader = CSV.read("path/to/file.csv")
    local_model = BigML::Model.new(model)
    test_reader.each do | row|
        input_data = fields.pair(row.collect {| val| val.to_f }, objective_field)
        prediction = local_model.predict(input_data, {'by_name' => false})
    end

If missing values are present, the ``Fields`` object can return a dict
with the ids of the fields that contain missing values and its count. The
following example:

.. code-block:: ruby

    api = BigML::Api.new
    dataset = api.get_dataset("dataset/5339d42337203f233e000015")

    fields = BigML::Fields.new(dataset)
    fields.missing_counts()

would output:

.. code-block:: ruby

    {'000003' => 1, '000000' => 1, '000001' => 1}

if the there was a missing value in each of the fields whose ids are
``000003``, ``000000``, ``000001``.

You can also obtain the counts of errors per field using the ``errors_count``
method of the api:

.. code-block:: ruby

    api = BigML::Api.new
    dataset = api.get_dataset("dataset/5339d42337203f233e000015")
    api.error_counts(dataset)

The generated output is like the one in ``missing_counts``, that is, the error
counts per field:

.. code-block:: ruby

    {'000000' => 1}
    

Rule Generation
---------------

You can also use a local model to generate a IF-THEN rule set that can be very
helpful to understand how the model works internally.

.. code-block:: ruby

     local_model.rules()
     IF petal_length > 2.45 AND
         IF petal_width > 1.65 AND
             IF petal_length > 5.05 THEN
                 species = Iris-virginica
             IF petal_length <= 5.05 AND
                 IF sepal_width > 2.9 AND
                     IF sepal_length > 5.95 AND
                         IF petal_length > 4.95 THEN
                             species = Iris-versicolor
                         IF petal_length <= 4.95 THEN
                             species = Iris-virginica
                     IF sepal_length <= 5.95 THEN
                         species = Iris-versicolor
                 IF sepal_width <= 2.9 THEN
                     species = Iris-virginica
         IF petal_width <= 1.65 AND
             IF petal_length > 4.95 AND
                 IF sepal_length > 6.05 THEN
                     species = Iris-virginica
                 IF sepal_length <= 6.05 AND
                     IF sepal_width > 2.45 THEN
                         species = Iris-versicolor
                     IF sepal_width <= 2.45 THEN
                         species = Iris-virginica
             IF petal_length <= 4.95 THEN
                 species = Iris-versicolor
     IF petal_length <= 2.45 THEN
         species = Iris-setosa

Summary generation
------------------

You can also print the model from the point of view of the classes it predicts
with ``local_model.summarize()``.
It shows a header section with the training data initial distribution per class
(instances and percentage) and the final predicted distribution per class.

Then each class distribution is detailed. First a header section
shows the percentage of the total data that belongs to the class (in the
training set and in the predicted results) and the rules applicable to
all the
the instances of that class (if any). Just after that, a detail section shows
each of the leaves in which the class members are distributed.
They are sorted in descending
order by the percentage of predictions of the class that fall into that leaf
and also show the full rule chain that leads to it.

::

    Data distribution:
        Iris-setosa: 33.33% (50 instances)
        Iris-versicolor: 33.33% (50 instances)
        Iris-virginica: 33.33% (50 instances)


    Predicted distribution:
        Iris-setosa: 33.33% (50 instances)
        Iris-versicolor: 33.33% (50 instances)
        Iris-virginica: 33.33% (50 instances)


    Field importance:
        1. petal length: 53.16%
        2. petal width: 46.33%
        3. sepal length: 0.51%
        4. sepal width: 0.00%


    Iris-setosa : (data 33.33% / prediction 33.33%) petal length <= 2.45
        · 100.00%: petal length <= 2.45 [Confidence: 92.86%]


    Iris-versicolor : (data 33.33% / prediction 33.33%) petal length > 2.45
        · 94.00%: petal length > 2.45 and petal width <= 1.65 and petal length <= 4.95 [Confidence: 92.44%]
        · 2.00%: petal length > 2.45 and petal width <= 1.65 and petal length > 4.95 and sepal length <= 6.05 and petal width > 1.55 [Confidence: 20.65%]
        · 2.00%: petal length > 2.45 and petal width > 1.65 and petal length <= 5.05 and sepal width > 2.9 and sepal length > 6.4 [Confidence: 20.65%]
        · 2.00%: petal length > 2.45 and petal width > 1.65 and petal length <= 5.05 and sepal width > 2.9 and sepal length <= 6.4 and sepal length <= 5.95 [Confidence: 20.65%]


    Iris-virginica : (data 33.33% / prediction 33.33%) petal length > 2.45
        · 76.00%: petal length > 2.45 and petal width > 1.65 and petal length > 5.05 [Confidence: 90.82%]
        · 12.00%: petal length > 2.45 and petal width > 1.65 and petal length <= 5.05 and sepal width <= 2.9 [Confidence: 60.97%]
        · 6.00%: petal length > 2.45 and petal width <= 1.65 and petal length > 4.95 and sepal length > 6.05 [Confidence: 43.85%]
        · 4.00%: petal length > 2.45 and petal width > 1.65 and petal length <= 5.05 and sepal width > 2.9 and sepal length <= 6.4 and sepal length > 5.95 [Confidence: 34.24%]
        · 2.00%: petal length > 2.45 and petal width <= 1.65 and petal length > 4.95 and sepal length <= 6.05 and petal width <= 1.55 [Confidence: 20.65%]


You can also use ``local_model.get_data_distribution()`` and
``local_model.get_prediction_distribution()`` to obtain the training and
prediction basic distribution
information as a list (suitable to draw histograms or any further processing).

Local ensembles have a ``local_ensemble.summarize()`` method too, the output
in this case shows only the data distribution and field importance sections.

For local clusters, the ``local_cluster.summarize()`` method prints also the
data distribution, the training data statistics per cluster and the basic
intercentroid distance statistics