Pie Chart

Part of the video course: D3.js in Motion.

This pie chart shows the estimated number of adherents to various religions in 2010. The data is from the Pew Research Center Global Religious Landscape data set.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <script src="https://d3js.org/d3.v4.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3-legend/2.24.0/d3-legend.min.js"></script>
    <title>Pie Chart</title>
    <style>
      body {
        margin: 0px;
      }
      .domain {
        display: none;
      }
      .legendCells text {
        fill: #8E8883;
        font-size: 28pt;
        font-family: sans-serif;
      }
      .legend-label {
        fill: #635F5D;
        font-size: 50pt;
        font-family: sans-serif;
      }
    </style>
  </head>
  <body>
    <svg width="960" height="500"></svg>
    <script>
      const pieValue = d => d.population;
      const colorValue = d => d.religion;
      const colorLabel = 'Religion';
      const margin = { left: 20, right: 400, top: 1, bottom: 1 };

const svg = d3.select('svg');
      const width = svg.attr('width');
      const height = svg.attr('height');
      const innerWidth = width - margin.left - margin.right;
      const innerHeight = height - margin.top - margin.bottom;

const pie = d3.pie().value(pieValue);
      const arc = d3.arc()
        .innerRadius(0)
        .outerRadius(innerHeight / 2);

colorLegendG.append('text')
          .attr('class', 'legend-label')
          .attr('x', -30)
          .attr('y', -40)
          .text(colorLabel);

const colorScale = d3.scaleOrdinal()
        .range(d3.schemeCategory10);

const colorLegend = d3.legendColor()
        .scale(colorScale)
        .shape('circle');

const row = d => {
        d.population = +d.population;
        return d;
      };

d3.csv('religionWorldTotals.csv', row, data => {
        colorScale.domain(data.map(colorValue));

const arcs = pie(data);

pieG.selectAll('path').data(arcs)
          .enter().append('path')
            .attr('d', arc)
            .attr('fill', d => colorScale(colorValue(d.data)));

colorLegendG.call(colorLegend)
          .selectAll('.cell text')
            .attr('dy', '0.1em');
      });
    </script>
  </body>
</html>

https://d3js.org/d3.v4.min.js

https://cdnjs.cloudflare.com/ajax/libs/d3-legend/2.24.0/d3-legend.min.js