Religions Pie Chart

A pie chart of world religions with a color legend. This is example 27 from the screencast Splitting Charts.

Data from Pew Research Center Global Religious Landscape data set
Using d3-legend
Draws from Using d3-legend

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>D3 Example</title>
    <script src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/d3-legend/1.1.0/d3-legend.js"></script>
    <link href='https://fonts.googleapis.com/css?family=Open+Sans' rel='stylesheet' type='text/css'>
    <style>
    
      .axis text {
        font-family: 'Open Sans', sans-serif;
        font-size: 32pt;
      }

.axis path, .axis line {
        fill: none;
        stroke: #000;
        shape-rendering: crispEdges;
      }

.color-legend text {
        font-family: 'Open Sans', sans-serif;
        font-size: 29pt;
      }

</style>
  </head>
  <body>
    <script>

var outerWidth = 960;
      var outerHeight = 500;
      var margin = { left: 11, top: 33, right: 377, bottom: 88 };
      var radiusMax = 180;

var xColumn = "name";
      var sliceSizeColumn = "population";
      var colorColumn = "religion";

var innerWidth  = outerWidth  - margin.left - margin.right;
      var innerHeight = outerHeight - margin.top  - margin.bottom;

var svg = d3.select("body").append("svg")
        .attr("width",  outerWidth)
        .attr("height", outerHeight);
      var g = svg.append("g")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
      var xAxisG = g.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + innerHeight + ")");
      var pieG = g.append("g");

var colorLegendG = g.append("g")
        .attr("class", "color-legend")
        .attr("transform", "translate(595, 20)");

var xScale = d3.scale.ordinal().rangePoints([0, innerWidth]);
      var colorScale = d3.scale.category10();

var xAxis = d3.svg.axis().scale(xScale).orient("bottom")
        .outerTickSize(0);

var pie = d3.layout.pie();
      var arc = d3.svg.arc();
      arc.outerRadius(radiusMax);
      arc.innerRadius(0);

var colorLegend = d3.legend.color()
        .scale(colorScale)
        .shapePadding(3)
        .shapeWidth(40)
        .shapeHeight(40)
        .labelOffset(4);

function render(data){

xScale.domain(data.map( function (d){ return d[xColumn]; }));
        colorScale.domain(data.map(function (d){ return d[colorColumn]; }));
        pie.value(function(d) { return d[sliceSizeColumn]; });

xAxisG.call(xAxis);

var pieData = pie(data);

pieG.attr("transform", "translate(" + innerWidth / 2 + "," + innerHeight / 2 + ")");

var slices = pieG.selectAll("path").data(pieData);
        slices.enter().append("path");
        slices
          .attr("d", arc)
          .attr("fill", function (d){ return colorScale(d.data[colorColumn]); });
        slices.exit().remove();

colorLegendG.call(colorLegend);

}

function type(d){
        d.name = "World";
        d.population = +d.population;
        return d;
      }

d3.csv("religionWorldTotals.csv", type, render);

</script>
  </body>
</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js

https://cdnjs.cloudflare.com/ajax/libs/d3-legend/1.1.0/d3-legend.js