MinnesotaPopulation/index.html at master · cbui505/MinnesotaPopulation · GitHub

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<!DOCTYPE html>
<meta charset="utf-8">
<style>

/* css properties */
svg {
  font: 10px sans-serif;
}

.caption {
  font-weight: bold;
}

.key path {
  display: none;
}

.key line {
  stroke: #000;
  shape-rendering: crispEdges;
}

.county-border {
  fill: none;
  stroke: #000;
  stroke-opacity: .3;
}
.census-border {
  fill: none;
  stroke: #000;
  stroke-opacity: .3;
}
.state-border {
  fill: none;
  stroke: #000;
  stroke-opacity: .7;
}

</style>
<body>
<!-- Add title -->
<h1  style = "text-align:center">Minnesota Population Density, 2014</h1>
<!-- Add input buttons for user -->
<input id = "color" type = "button" value = "color"  onclick = "changeColor();" />
<input id = "censustract" type = "button" value = "tracts"  onclick = "changeTracts();"/>
<input id = "state" type = "button" value = "state"  onclick = "changeStateBorder();" />
<!-- use these libraries for js -->
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>

/* Initialization og variables */

//initialize height, width of svg
var width = 960,
    height = 800;

//format ticks
var formatNumber = d3.format(",d");

//store how many times each button is pressed
var colorcount = 0;      //store number of times user presses color button
var tractcount = 0;      //store number of times user presses tract button
var statecount = 0;      //store number of times user presses state button

var path = d3.geo.path()
    .projection(null);

//define color scale, mapping values in certain ranges to corresponding color
var color = d3.scale.threshold()
    .domain([1, 10, 50, 100, 500, 1000, 2000, 5000])
    .range(["#fff7ec", "#fee8c8", "#fdd49e", "#fdbb84", "#fc8d59", "#ef6548", "#d7301f", "#b30000", "#7f0000"]);
    //.range(["#19ff19", "#00e500", "#00cc00", "#00b200", "#009900", "#007f00", "#006600", "#004c00", "#003300"])

// define scale for legend
var x = d3.scale.linear()
    .domain([0, 5100])
    .range([0, 480]);

//make the legend
var xAxis = d3.svg.axis()
    .scale(x)              //scale using above scale
    .orient("bottom")      //orient ticks on bottom
    .tickSize(13)
    .tickValues(color.domain())   //get values for ticks
    .tickFormat(function(d) { return d >= 100 ? formatNumber(d) : null; });  //remove tick value from legend if <100

    //define svg element
var svg = d3.select("body").append("svg")
    .attr("width", width)    //set width and height using above values
    .attr("height", height);

    //defing grouping element
var g = svg.append("g")
    .attr("class", "key")
    .attr("transform", "translate(440,40)");   //position it

    //adding in rectangles in legend
g.selectAll("rect")
     //bind data of color scale from above
    .data(color.range().map(function(d, i) {
      return {
        x0: i ? x(color.domain()[i - 1]) : x.range()[0],
        x1: i < color.domain().length ? x(color.domain()[i]) : x.range()[1],
        z: d
      };
    }))
     //add placeholders and append there
  .enter().append("rect")
     //set height of all rect
    .attr("height", 8)
     //set up each x position and width
    .attr("x", function(d) { return d.x0; })
    .attr("width", function(d) { return d.x1 - d.x0; })
     //fill with corresponding color
    .style("fill", function(d) { return d.z; });

    //adding label to legend
g.call(xAxis).append("text")
    .attr("class", "caption")
    .attr("y", -6)
    .text("Population per square mile");

//-----------------------------------------------------------------------------------------------------------

/* Reading in data from JSON file */

d3.json("mn.json", function(error, mn) {
  if (error) throw error;
  console.log(mn.objects)    //debug
  //get census tracts from input file
  var tracts = topojson.feature(mn, mn.objects["cb_2015_27_tract_500k"]);

  // Clip tracts to land.
  svg.append("defs").append("clipPath")
      .attr("id", "clip-land")
    .append("path")
      .datum(topojson.feature(mn, mn.objects["MN-COUNTY"]))
      .attr("d", path);

  // Group tracts by color for faster rendering.
  svg.append("g")
      .attr("class", "tract")
      .attr("clip-path", "url(#clip-land)")
    .selectAll("path")
      .data(d3.nest()
        .key(function(d) { return color(d.properties.population / d.properties.area * 2.58999e6); })
        .entries(tracts.features.filter(function(d) { return d.properties.area; })))
    .enter().append("path")
      .style("fill", function(d) { return d.key; })
      .attr("d", function(d) { return path({type: "FeatureCollection", features: d.values}); });

      // Draw county borders.
      svg.append("path")
      .datum(topojson.mesh(mn, mn.objects["MN-COUNTY"], function(a, b) { return a !== b; }))
      .attr("class", "county-border")
      .attr("d", path);

      //Draw census tract borders
      svg.append("path")
      .datum(topojson.mesh(mn, mn.objects["cb_2015_27_tract_500k"], function(a, b) { return a !== b; }))
      .attr("class", "census-border")
      .attr("d", path);

      //draw state border
      svg.append("path")
      .datum(topojson.mesh(mn, mn.objects["MN-STATE"], function(a, b) { return a == b; }))
      .attr("class", "state-border")
      .attr("d", path);


//-----------------------------------------------------------------------------------------------------------

/*  functions that control changes to map when a button is clicked  */

      //function that changes the color scheme when called
  changeColor = function(){
        //use colorcount to check which color to use
        //increment counter to check what color scheme to use on next click
        colorcount++;

        //if odd number of clicks, change to green scheme
        if(colorcount%2 == 1){
            color.range(["#19ff19", "#00e500", "#00cc00", "#00b200", "#009900", "#007f00", "#006600", "#004c00", "#003300"])
        }
      //otherwise set to default default scheme
        else{
          color.range(["#fff7ec", "#fee8c8", "#fdd49e", "#fdbb84", "#fc8d59", "#ef6548", "#d7301f", "#b30000", "#7f0000"]);
        }

      //update the color of the legend
      g.selectAll("rect")
        .data(color.range().map(function(d, i) {
           return {
               x0: i ? x(color.domain()[i - 1]) : x.range()[0],
               x1: i < color.domain().length ? x(color.domain()[i]) : x.range()[1],
               z: d
            };
         }))
         .style("fill", function(d) { return d.z; });

      //set color of census tracts
      svg.selectAll("tract")
           .data(d3.nest()
           .key(function(d) { return color(d.properties.population / d.properties.area * 2.58999e6); })
           .entries(tracts.features.filter(function(d) { return d.properties.area; })))
           .enter().append("path")
           .style("fill", function(d) { return d.key; })
           .attr("d", function(d) { return path({type: "FeatureCollection", features: d.values}); });

      // redraw county borders.
          svg.append("path")
            .datum(topojson.mesh(mn, mn.objects["MN-COUNTY"], function(a, b) { return a !== b; }))
            .attr("class", "county-border")
            .attr("d", path);

      //if color is changed from default, redraw the following
      if(colorcount%2==1){
      //redraw state border
          svg.append("path")
            .datum(topojson.mesh(mn, mn.objects["MN-STATE"], function(a, b) { return a == b; }))
            .attr("class", "state-border")
            .attr("d", path);
      }
      //Draw census tract borders
         svg.append("path")
            .datum(topojson.mesh(mn, mn.objects["cb_2015_27_tract_500k"], function(a, b) { return a !== b; }))
            .attr("class", "census-border")
            .attr("d", path);

      //if user wanted tracts to be hidden
      if(tractcount%2 == 1){
            svg.selectAll(".census-border")
            .style("stroke-opacity", 0)
      }
      //show tracts
      else{
          svg.selectAll(".census-border")
            .style("stroke-opacity", 0.3)
      }
      //if user wanted to hide state border
      if(statecount%2 == 1){
          svg.selectAll(".state-border")
             .style("stroke-opacity", 0)
      }
      //show state border
      else{
          svg.selectAll(".state-border")
             .style("stroke-opacity", 0.7)
      }
  }

  //function that hides/shows tracts when called
  changeTracts = function(){
      //increment tractcount for next
      tractcount++;
      //if odd count, hide tracts
      if(tractcount%2 == 1){
          svg.selectAll(".census-border")
             .style("stroke-opacity", 0)
      }
      //otherwise, display tracts
      else{
          svg.selectAll(".census-border")
             .style("stroke-opacity", 0.3)
      }
  }

  //function that hides/displays state border when called
  changeStateBorder = function(){
      //increment number of times button was pressed
      statecount++;
      //if odd count, hide border
      if(statecount%2 == 1){
          svg.selectAll(".state-border")
             .style("stroke-opacity", 0)
      }
      //otherwise, display it
      else{
          svg.selectAll(".state-border")
             .style("stroke-opacity", 0.7)
      }
  }

});
//proper display on github
d3.select(self.frameElement).style("height", height + "px");

</script>

<!-- Additional Information to display at bottom -->
<h4>Christopher Bui</h4>
<h4>Instructor: Suresh Lodha</h4>
<h4>CMPS 165: Data Programming for Visualization</h4>
<h4>Fall 2016</h4>
</body>