Question

我想将图例添加到我的日历热图中。但是，目前图例只包含两个元素> 0%和> NaN%。我尝试了不同的方法来设置图例，但仍无法解决问题。

如何定义值应来自colorScale？为什么我的值为> 0%和> NaN%而不是colorScale中定义的值？

<!DOCTYPE html>
<meta charset="utf-8">
<html>
  <head>
    <style>
      rect.bordered {
        stroke: #E6E6E6;
        stroke-width:2px;   
      }

      text.mono {
        font-size: 10pt;
        font-family: Consolas, courier;
        fill: #000;
      }

      text    {
        font-family: Consolas, courier;
        font-size:1.0em;
      }

      text.axis-workweek {
        fill: #000;
      }

      text.axis-worktime {
        fill: #000;
      }
    </style>
    <script src="http://d3js.org/d3.v3.js"></script>
  </head>
  <body>
    <div id="chart"></div>
    </div>
    <script type="text/javascript">
     var title="";
      var margin = { top: 90, right: 0, bottom: 80, left: 30 },
          width = 960 - margin.left - margin.right,
          height = 900 - margin.top - margin.bottom,
          gridSize = Math.floor(width / 42),
          legendElementWidth = gridSize*2,
          buckets = 5,
          colors = ["#c7e9b4","#41b6c4","#1d91c0","#225ea8"], // alternatively colorbrewer.YlGnBu[9]
          days = ["1", "2", "3", "4", "5", "6", "7","8", "9", "10", "11", "12","13", "14", "15", "16", "17","18", "19", "20", 
"21", "22","23", "24", "25", "26", "27","28", "29", "30", "31"],
          times = ["7:00", "8:00", "9:00", "10:00", "11:00", "12:00", "13:00", "14:00", "15:00", "16:00", "17:00", "18:00", "19:00", "20:00", "21:00"];
          datasets = ["data.tsv"];

      var svg = d3.select("#chart").append("svg")
          .attr("width", width + margin.left + margin.right)
          .attr("height", height + margin.top + margin.bottom)
          .append("g")
          .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

      svg.append("text")
        .attr("x",0)
        .attr("y",-40)
        .text(title);

      var dayLabels = svg.selectAll(".dayLabel")
          .data(days)
          .enter().append("text")
            .text(function (d) { return d; })
            .attr("x", 0)
            .attr("y", function (d, i) { return i * gridSize; })
            .style("text-anchor", "end")
            .attr("transform", "translate(-6," + gridSize / 1.5 + ")")
            .attr("class", function (d, i) { return ((i >= 0 && i <= 4) ? "dayLabel mono axis axis-workweek" : "dayLabel mono axis"); });

      var timeLabels = svg.selectAll(".timeLabel")
          .data(times)
          .enter().append("text")
            .text(function(d) { return d; })
            .attr("x", function(d, i) { return i * gridSize * 2.1; })
            .attr("y", 0)
            .style("text-anchor", "middle")
            .attr("transform", "translate(" + gridSize / 2 + ", -6)")
            .attr("class", function(d, i) { return ((i >= 7 && i <= 16) ? "timeLabel mono axis axis-worktime" : "timeLabel mono axis"); });

      var heatmapChart = function(tsvFile) {
        d3.tsv(tsvFile,
        function(d) {
          return {
            day: +d.day,
            hour: +d.hour,
            value: +d.value
          };
        },
        function(error, data) {
      var colorScale = d3.scale.threshold()
             .domain([5, 10, 15])
             .range(colors);

          var cards = svg.selectAll(".hour")
              .data(data, function(d) {return d.day+':'+d.hour;});

          cards.append("title");

          cards.enter().append("rect")
              .attr("x", function(d) { return (d.hour - 7) * gridSize * 2.05; })
              .attr("y", function(d) { return (d.day - 1) * gridSize; })
              .attr("rx", 4)
              .attr("ry", 4)
              .attr("class", "hour bordered")
              .attr("width", gridSize*2)
              .attr("height", gridSize)
              .style("fill", colors[0]);

          cards.transition().duration(1000)
              .style("fill", function(d) { return colorScale(d.value); });

          cards.select("title").text(function(d) { return d.value; });

          cards.exit().remove();

          var legend = svg.selectAll(".legend")
              .data([0].concat(colorScale), function(d) { return d; });

          legend.enter().append("g")
              .attr("class", "legend");

          legend.append("rect")
            .attr("x", height)
            .attr("y", function(d, i) { return legendElementWidth * (i-0.5); })
            .attr("width", gridSize / 2 )
            .attr("height", legendElementWidth)
            .style("fill", function(d, i) { return colors[i]; });

          legend.append("text")
            .attr("class", "mono")
            .text(function(d) { return "≥ " + Math.round(d) + "%"; })
            .attr("x", (height) + gridSize)
            .attr("y", function(d, i) { return legendElementWidth*i; } );

          legend.exit().remove();

        });  
      };

      heatmapChart(datasets[0]);

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

这是我目前的结果：

Answer 1

它只是代码中的一个小错误。您为图例提供的数据是一个包含零和colorScale函数的数组：

var legend = svg.selectAll(".legend")
  .data([0].concat(colorScale), function(d) { return d; });

你可能想要这样的东西：

var colorScaleDomain = [5, 10, 15]
var colorScale = d3.scale.threshold()
  .domain(colorScaleDomain)
  .range(colors);
(...)

var legend = svg.selectAll(".legend")
  .data([0].concat(colorScaleDomain));

如何将图例添加到日历热图

1 个答案: