D3 Examples - d3-ez : Rose Chart Example

d3-ez : Rose Chart Example

Rose Chart Example

The Polar Area chart is similar to a usual pie chart, except sectors are equal angles and differ rather in how far each sector extends from the center of the circle. The polar area diagram is used to plot cyclic phenomena (e.g., count of deaths by month).

FUNCTION: Comparison, Distribution, Trend over time

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<!DOCTYPE html>
<html>
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<head>
  <title>d3-ez : Rose Chart Example</title>
  <script src="https://d3js.org/d3.v5.min.js"></script>
  <script src="https://raw.githack.com/jamesleesaunders/d3-ez/master/dist/d3-ez.js"></script>
  <link rel="stylesheet" type="text/css" href="https://rawgit.com/jamesleesaunders/d3.ez/master/dist/d3-ez.css" />
</head>
  
<body>
  <div id="chartholder"></div>
  <br />
  <div>Value: <span id="message"></span></div>
​
  <script type="text/javascript">
    d3.json("nightingale_rose.json").then(function(json) {
      // Florence Nightingale Data Source: https://pointedanalytics.wordpress.com/2013/07/14/plotting-coxcombs-using-ggplot2/
​
      var colors = ["#599ad3", "#727272", "#f1595f"];
      var chart = d3.ez.chart.roseChart().colors(colors);
      var legend = d3.ez.component.legend().title("Causes of Mortality");
      var title = d3.ez.component.title().mainText("Diagram of the Causes of Mortality in the Army in The East").subText("April 1854 to March 1855");
​
      // Convert json to d3-ez data format
      var monthNames = [
        "January", "February", "March", "April", "May", "June",
        "July", "August", "September", "October", "November", "December"
      ];
      var data = d3.nest()
        .key(function(d) {
          return d.date;
        })
        .entries(json).map(function(obj) {
          var rec = obj.values[0];
          var scalar = 1000 * 12 / rec.army_size;
          var datetime = new Date(obj.key);
​
          var values = {
            key: monthNames[datetime.getMonth()],
            datetime: datetime,
            values: [{
                key: 'Zymotic Diseases',
                value: Math.sqrt(rec.zymotic_diseases * scalar) / Math.PI
              },
              {
                key: 'Other Causes',
                value: Math.sqrt(rec.all_other_causes * scalar) / Math.PI
              },
              {
                key: 'Wounds & Injuries',
                value: Math.sqrt(rec.wounds_and_injuries * scalar) / Math.PI
              }
            ]
          };
          return values;
        })
        .filter(function(d) {
          return d.datetime < new Date("1855-04-01T07:00:00.000Z");
        });
​
      // Create chart base
      var myChart = d3.ez.base()
        .width(750)
        .height(400)
        .chart(chart)
        .legend(legend)
        .title(title)
        .on("customValueMouseOver", function(d) {
          d3.select("#message").text(d.value);
        });
​
      // Add to page
      d3.select("#chartholder")
        .datum(data)
        .call(myChart);
    });
  </script>
</body>
​
</html>
    