Wordcloud with proportional font size in d3.js





The previous post described how to build a very basic wordcloud with the d3-cloud javascript plugin. This post shows how to make the size of words proportionnal to their occurence.


Wordcloud section

Steps:

  • See the previous post for a very basic wordcloud and a few customization with the d3-cloud plugin.

  • Here the idea is to make the word that have a high occurence bigger.

  • The .word argument of the layout call can recover as many feature as needed. It is thus possible to give it the size (occurence)

  • Thus, this size data can be used to be provided in the .fontSize argument.

<!DOCTYPE html>
<meta charset="utf-8">

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

<!-- Load d3-cloud -->
<script src="https://cdn.jsdelivr.net/gh/holtzy/D3-graph-gallery@master/LIB/d3.layout.cloud.js"></script>

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

<script>

// List of words
var myWords = [{word: "Running", size: "10"}, {word: "Surfing", size: "20"}, {word: "Climbing", size: "50"}, {word: "Kiting", size: "30"}, {word: "Sailing", size: "20"}, {word: "Snowboarding", size: "60"} ]

// set the dimensions and margins of the graph
var margin = {top: 10, right: 10, bottom: 10, left: 10},
    width = 450 - margin.left - margin.right,
    height = 450 - 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 + ")");

// Constructs a new cloud layout instance. It run an algorythm to find the position of words that suits your requirements
// Wordcloud features that are different from one word to the other must be here
var layout = d3.layout.cloud()
  .size([width, height])
  .words(myWords.map(function(d) { return {text: d.word, size:d.size}; }))
  .padding(5)        //space between words
  .rotate(function() { return ~~(Math.random() * 2) * 90; })
  .fontSize(function(d) { return d.size; })      // font size of words
  .on("end", draw);
layout.start();

// This function takes the output of 'layout' above and draw the words
// Wordcloud features that are THE SAME from one word to the other can be here
function draw(words) {
  svg
    .append("g")
      .attr("transform", "translate(" + layout.size()[0] / 2 + "," + layout.size()[1] / 2 + ")")
      .selectAll("text")
        .data(words)
      .enter().append("text")
        .style("font-size", function(d) { return d.size; })
        .style("fill", "#69b3a2")
        .attr("text-anchor", "middle")
        .style("font-family", "Impact")
        .attr("transform", function(d) {
          return "translate(" + [d.x, d.y] + ")rotate(" + d.rotate + ")";
        })
        .text(function(d) { return d.text; });
}
</script>

Related blocks →

  • Example section of d3-cloud documentation - by Jason Davies