add HDF4 h4{size,exists,variables}

Author: scivision

+stdlib/+hdf5nc/h4exists.m

@@ -0,0 +1,18 @@
+function exists = h4exists(file, variable)
+
+arguments
+  file (1,1) string {mustBeFile}
+  variable (1,1) string {mustBeNonzeroLengthText}
+end
+
+exists = false;
+
+try
+  sds = hdfinfo(file).SDS;
+  i = string(sds.Name) == variable;
+  exists = any(i);
+catch e
+  if e.identifier ~= "MATLAB:imagesci:h5info:unableToFind"
+    rethrow(e)
+  end
+end

+stdlib/+hdf5nc/h4size.m

@@ -7,7 +7,7 @@
 
 sds = hdfinfo(file).SDS;
 
-i = string(hdfinfo(file).SDS.Name) == variable;
+i = string(sds.Name) == variable;
 if ~all(i)
   error(variable + " is not an SDS in " + file)
 end

+stdlib/+hdf5nc/h4variables.m

@@ -0,0 +1,13 @@
+function names = h4variables(file)
+
+arguments
+  file (1,1) string {mustBeFile}
+end
+
+finf = hdfinfo(file);
+
+ds = finf.SDS;
+
+names = string({ds.Name});
+
+end

+stdlib/+hdf5nc/h5variables.m

@@ -5,8 +5,6 @@
   group string {mustBeScalarOrEmpty} = string.empty
 end
 
-names = string.empty;
-
 if isempty(group) || strlength(group) == 0
   finf = h5info(file);
 else
@@ -16,9 +14,9 @@
 ds = finf.Datasets;
 
 if isempty(ds)
-  return
+  names = string.empty;
+else
+  names = string({ds.Name});
 end
 
-names = string({ds.Name});
-
-end % function
+end

+stdlib/+hdf5nc/ncvariables.m

@@ -5,19 +5,18 @@
   group string {mustBeScalarOrEmpty} = string.empty
 end
 
-names = string.empty;
-
 if isempty(group) || strlength(group) == 0
   finf = ncinfo(file);
 else
   finf = ncinfo(file, group);
 end
 
 ds = finf.Variables(:);
+
 if isempty(ds)
-  return
+  names = string.empty;
+else
+  names = string({ds.Name});
 end
 
-names = string({ds.Name});
-
-end % function
+end

+stdlib/h4exists.m

@@ -0,0 +1,19 @@
+function exists = h4exists(file, variable)
+%% H5EXISTS(file, variable)
+% check if object exists in HDF4 file
+%
+%%% Inputs
+% * file: data filename
+% * variable: path of variable in file
+%
+%%% Outputs
+% * exists: boolean
+
+arguments
+  file (1,1) string
+  variable (1,1) string
+end
+
+exists = stdlib.hdf5nc.h4exists(file, variable);
+
+end

+stdlib/h4size.m

@@ -0,0 +1,19 @@
+function fsize = h4size(file, variable)
+%% h5size(file, variable)
+% get size (shape) of a data file variable
+%
+%%% Inputs
+% filename: data filename
+% variable: name of variable inside file
+%
+%%% Outputs
+% fsize: vector of variable size per dimension. Empty if scalar variable.
+
+arguments
+    file (1,1) string
+    variable (1,1) string
+end
+
+fsize = stdlib.hdf5nc.h4size(file, variable);
+
+end

+stdlib/h4variables.m

@@ -0,0 +1,19 @@
+function names = h4variables(file)
+%% h5variables(file, group)
+% get dataset names in a file under group
+% default is datasets under "/", optionally under "/group"
+%
+%%% Inputs
+% * file: filename
+% * group: group name (optional)
+%
+%%% Outputs
+% * names: variable names
+
+arguments
+    file (1,1) string
+end
+
+names = stdlib.hdf5nc.h4variables(file);
+
+end

+stdlib/h5variables.m

@@ -11,7 +11,7 @@
 % * names: variable names
 
 arguments
-    file (1,1) string {mustBeFile}
+    file (1,1) string
     group string {mustBeScalarOrEmpty} = string.empty
 end
 

test/TestHDF4.m

@@ -0,0 +1,47 @@
+classdef TestHDF4 < matlab.unittest.TestCase
+
+properties
+TestData
+end
+
+methods (TestClassSetup)
+function setup_path(tc)
+tc.TestData.basic = fullfile(matlabroot, "toolbox/matlab/demos/example.hdf");
+end
+end
+
+methods (Test)
+
+function test_exists(tc)
+import matlab.unittest.constraints.IsScalar
+basic = tc.TestData.basic;
+
+e = stdlib.h4exists(basic, "Example SDS");
+
+tc.verifyThat(e, IsScalar)
+tc.verifyTrue(e);
+
+tc.verifyFalse(stdlib.h4exists(basic, "/j"))
+
+end
+
+
+function test_size(tc)
+basic = tc.TestData.basic;
+
+s = stdlib.h4size(basic, "Example SDS");
+tc.verifyEqual(s, [16, 5])
+
+end
+
+
+function test_vars(tc)
+basic = tc.TestData.basic;
+
+v = stdlib.h4variables(basic);
+tc.verifyTrue(any(contains(v, "Example SDS")))
+end
+
+
+end
+end