Cleveland dot plot in d3.js





This post describes how to build a Cleveland dot plot with d3.js. It is basically a lollipop plot with 2 data series represented for each group.


Lollipop section

Steps:

  • You probably want to understand how to build a basic lollipop plot first.

  • Then the idea is pretty much the same, building one circle per variable, and joining them with a line
<!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: 30, left: 30},
    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 + ")");

// Parse the Data
d3.csv("https://raw.githubusercontent.com/holtzy/D3-graph-gallery/master/DATA/data_cleveland.csv", function(data) {


  // Add X axis
  var x = d3.scaleLinear()
    .domain([-1, 6])
    .range([ 0, width]);
  svg.append("g")
    .attr("transform", "translate(0," + height + ")")
    .call(d3.axisBottom(x))

  // Y axis
  var y = d3.scaleBand()
    .range([ 0, height ])
    .domain(data.map(function(d) { return d.group; }))
    .padding(1);
  svg.append("g")
    .call(d3.axisLeft(y))

  // Lines
  svg.selectAll("myline")
    .data(data)
    .enter()
    .append("line")
      .attr("x1", function(d) { return x(d.value1); })
      .attr("x2", function(d) { return x(d.value2); })
      .attr("y1", function(d) { return y(d.group); })
      .attr("y2", function(d) { return y(d.group); })
      .attr("stroke", "grey")
      .attr("stroke-width", "1px")

  // Circles of variable 1
  svg.selectAll("mycircle")
    .data(data)
    .enter()
    .append("circle")
      .attr("cx", function(d) { return x(d.value1); })
      .attr("cy", function(d) { return y(d.group); })
      .attr("r", "6")
      .style("fill", "#69b3a2")

  // Circles of variable 2
  svg.selectAll("mycircle")
    .data(data)
    .enter()
    .append("circle")
      .attr("cx", function(d) { return x(d.value2); })
      .attr("cy", function(d) { return y(d.group); })
      .attr("r", "6")
      .style("fill", "#4C4082")
})

</script>

Related blocks →

  • The most basic barplot with d3.js - link

  • Lollipop chart - link

  • Most basic lollipop chart - link