如何在D3.js中添加自定义SVG图形替换图表圆形为飞机形状

实现方案 #

你可以通过SVG的defs标签定义可复用的自定义图形模板，再通过D3调用模板替换原有圆形标记，具体修改后的完整代码如下：

<!-- Code from d3-graph-gallery.com -->
<!DOCTYPE html>
<meta charset="utf-8">

<!-- Load d3.js -->
<script src="https://d3js.org/d3.v4.js"></script>

<!-- Create a div where the graph will take place -->
<div id="my_dataviz"></div>

<script>
// set the dimensions and margins of the graph
var margin = {top: 10, right: 30, bottom: 90, left: 40},
    width = 460 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

// append the svg object to the body of the page
var svg = d3.select("#my_dataviz")
  .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 + ")");

// 定义飞机图形模板
svg.append("defs")
  .append("symbol")
  .attr("id", "airplane")
  .attr("viewBox", "0 0 313 305")
  .append("path")
  .attr("d", "m2,106h28l24,30h72l-44,-133h35l80,132h98c21,0 21,34 0,34l-98,0 -80,134h-35l43,-133h-71l-24,30h-28l15,-47");

// Parse the Data
d3.csv("https://raw.githubusercontent.com/holtzy/data_to_viz/master/Example_dataset/7_OneCatOneNum_header.csv", function(data) {

// X axis
var x = d3.scaleBand()
  .range([ 0, width ])
  .domain(data.map(function(d) { return d.Country; }))
  .padding(1);
svg.append("g")
  .attr("transform", "translate(0," + height + ")")
  .call(d3.axisBottom(x))
  .selectAll("text")
    .attr("transform", "translate(-10,0)rotate(-45)")
    .style("text-anchor", "end");

// Add Y axis
var y = d3.scaleLinear()
  .domain([0, 13000])
  .range([ height, 0]);
svg.append("g")
  .call(d3.axisLeft(y));

// Lines
svg.selectAll("myline")
  .data(data)
  .enter()
  .append("line")
    .attr("x1", function(d) { return x(d.Country); })
    .attr("x2", function(d) { return x(d.Country); })
    .attr("y1", function(d) { return y(d.Value); })
    .attr("y2", y(0))
    .attr("stroke", "grey")

// 替换原有圆形为飞机标记
svg.selectAll(".airplane-icon")
  .data(data)
  .enter()
  .append("use")
  .attr("xlink:href", "#airplane")
  .attr("width", 20)
  .attr("height", 20)
  .attr("transform", function(d) {
    // 调整偏移让飞机中心对准数据点
    return "translate(" + (x(d.Country) - 10) + "," + (y(d.Value) - 10) + ")"
  })
  .style("fill", "#69b3a2")
  .attr("stroke", "black")
})
</script>

如果需要调整飞机的大小，直接修改width和height属性即可，同步调整transform中的偏移值为宽高的一半，就能保证飞机中心始终和数据点位置对齐。

内容的提问来源于stack exchange，提问作者melanzane