如何使用d3.js在饼图转换图中显示标签？

Question

我正在使用 d3.js 的饼图转换图来可视化潜在客户。图已绘制，但图上未显示标签。

代码如下：

var w = 400,
h = 400,
r = Math.min(w, h) / 2,
data = [25,45],            // Data values
color = d3.scale.category20(),
arc = d3.svg.arc().outerRadius(r),
donut = d3.layout.pie();

var vis = d3.select("#pie-chart-div").append("svg")  // Place the chart in 'pie-chart-div'
    .data([data])
    .attr("width", w)
    .attr("height", h);

var arcs = vis.selectAll("g.arc")
    .data(donut)
  .enter().append("g")
    .attr("class", "arc")
    .attr("transform", "translate(" + r + "," + r + ")");

var paths = arcs.append("path")
    .attr("fill", function(d, i) { return color(i); });

paths.transition()
    .ease("bounce")
    .duration(2000)
    .attrTween("d", tweenPie);

paths.transition()
    .ease("elastic")
    .delay(function(d, i) { return 2000 + i * 50; })
    .duration(750)
    .attrTween("d", tweenDonut);

function tweenPie(b) {
  b.innerRadius = 0;
  var i = d3.interpolate({startAngle: 0, endAngle: 0}, b);
  return function(t) {
    return arc(i(t));
  };
}

function tweenDonut(b) {
  b.innerRadius = r * .6;
  var i = d3.interpolate({innerRadius: 0}, b);
  return function(t) {
    return arc(i(t));
  };
}

如何在饼图转换中显示标签？

Answer 1

要显示 "exact location" 中的文本（我认为它在圆弧的中间），您可以使用 centroid() 函数：

var labels = arcs.append("text")
    .attr("transform", function(d) { 
        d.innerRadius = 120;
        return "translate(" + arc.centroid(d) + ")"; 
    })
    .attr("dy", ".35em")
    .text(function(d) { return d.value; });

查看此演示：

var w = 400,
h = 400,
r = Math.min(w, h) / 2,
data = [25,45],            // Data values
color = d3.scale.category20(),
arc = d3.svg.arc().outerRadius(r),
donut = d3.layout.pie();

var vis = d3.select("body").append("svg")  // Place the chart in 'pie-chart-div'
    .data([data])
    .attr("width", w)
    .attr("height", h);

var arcs = vis.selectAll("g.arc")
    .data(donut)
  .enter().append("g")
    .attr("class", "arc")
    .attr("transform", "translate(" + r + "," + r + ")");

var paths = arcs.append("path")
    .attr("fill", function(d, i) { return color(i); });
  
var labels = arcs.append("text")
      .attr("transform", function(d) { d.innerRadius = 120; return "translate(" + arc.centroid(d) + ")"; })
      .attr("dy", ".35em")
      .text(function(d) { return d.value; });

paths.transition()
    .ease("bounce")
    .duration(2000)
    .attrTween("d", tweenPie);

paths.transition()
    .ease("elastic")
    .delay(function(d, i) { return 2000 + i * 50; })
    .duration(750)
    .attrTween("d", tweenDonut);

function tweenPie(b) {
  b.innerRadius = 0;
  var i = d3.interpolate({startAngle: 0, endAngle: 0}, b);
  return function(t) {
    return arc(i(t));
  };
}

function tweenDonut(b) {
  b.innerRadius = r * .6;
  var i = d3.interpolate({innerRadius: 0}, b);
  return function(t) {
    return arc(i(t));
  };
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

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javascript

charts

d3.js

pie-chart