Lynchings by State Pie Charts

A small multiples visualization of pie charts showing the proportion and total number of lynchings by US State and by Race from 1882-1968. Area of the pie slices corresponds to the number of people lynched. The data from the Archives at Tuskegee Institute.

Inspired by

American Lynches Map by @ Malcolm_Decuire
State Grid by @enjalot - created in this Video of Block Remix

forked from curran's block: Lynchings by State Pie Charts First Attempt

<!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: 12pt;
      }

.axis path, .axis line {
        fill: none;
        stroke: none;
      }

.color-legend text {
        font-family: 'Open Sans', sans-serif;
        font-size: 12pt;
      }

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

var outerWidth = 960;
      var outerHeight = 500;
      var margin = { left: 153, top: 1, right: 23, bottom: 1 };

var yColumn = "state";
      var xColumn = "group";
      var colorColumn = "race";
      var areaColumn = "lynchings";
      var radiusMax = 57;
      var numGroups = 6;

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 colorLegendG = svg.append("g")
        .attr("class", "color-legend")
        .attr("transform", "translate(24, 224)");

var yScale = d3.scale.ordinal().rangePoints([0, innerHeight], 1);
      
      var radiusScale = d3.scale.sqrt().range([0, radiusMax]);
      var colorScale = d3.scale.ordinal()
        .range(["#ffcda8", "#a35400"]);

var yAxis = d3.svg.axis().scale(yScale).orient("left");

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

var colorLegend = d3.legend.color()
        .scale(colorScale)
        .shapePadding(29)
        .shapeWidth(25)
        .shapeHeight(25)
        .labelOffset(9)
        .orient("horizontal");

function render(data, group){
        
        var groupG = g.append("g")
          .attr("transform", "translate(" + group * (innerWidth / (numGroups - 1)) + ", 0)");

yScale.domain(nested.map( function (d){ return d.key; }));
        colorScale.domain(nested[0].values.map(function (d){ return d[colorColumn]; }));
        pie.value(function(d) { return d[areaColumn]; });
        
        var pies = groupG.selectAll(".pie").data(nested);
        pies.enter().append("g").attr("class", "pie");
        pies.attr("transform", function (d){
          var y = yScale(d.key);
          return "translate(0," + y + ")";
        });
        pies.exit().remove();

var slices = pies.selectAll("path").data(function (d){
          return pie(d.values);
        });

slices.enter().append("path");
        slices
          .attr("d", function (d, i, j){
            arc.outerRadius(radiusScale(nested[j].areaColumnSum));
            return arc(d);
          })
          .attr("fill", function (d){ return colorScale(d.data[colorColumn]); });
        slices.exit().remove();

var yAxisG = groupG.append("g")
          .attr("class", "y axis");
        yAxisG.call(yAxis)
          .selectAll("text")
          .attr("dx", (-0.687379488768002 * (numGroups - group)) + 0.49152 + "em")
          //.attr("dy", "-0.2736816128em")
          //.style("text-anchor", "end")
          //.attr("transform", "rotate(-90)" )
       
        colorLegendG.call(colorLegend);
      }

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

d3.csv("lynchings-1882-1968-by-state-and-race.csv", type, function (data){
        
        // Sort by total
        data = data.sort(function (a, b){
          return b.Total - a.Total;
        });
        
        // Transform the data so it works with the nest logic.
        var transformed = [];
        
        data.forEach(function(d, i){
          
          // The "group" is the vertical column.
          var group = Math.floor(Math.sqrt(i) / 1.12);
          
          transformed.push({
            state: d.State,
            race: "White",
            lynchings: d.White,
            group: group
          });
          transformed.push({
            state: d.State,
            race: "Black",
            lynchings: d.Black,
            group: group
          });
        });
        
        var nested = d3.nest()
          .key(function (d){ return d[yColumn]; })
          .entries(transformed);
        
        // Compute sums for the radius field,
        // for setting the size of each pie.
        nested.forEach(function (xEntry){
          xEntry.areaColumnSum = d3.sum(xEntry.values, function (d){
            return d[areaColumn];
          });
        });

radiusScale.domain([
          0,
          d3.max(nested, function (xEntry){
            return xEntry.areaColumnSum;
          })
        ]);
        
        var groups = d3.nest()
          .key(function (d){ return d.group; })
          .entries(transformed);
        
        groups.forEach(function (groupData, i){
          render(groupData.values, i);
        });
        
        
      });

</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