treemap.js

// set the dimensions and margins of the graph
var margin = { top: 0, right: 0, bottom: 0, left: 0 },
  width = 960 - 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 + ")");

// Read data
d3.csv("./treemap.csv", function (data) {
  // stratify the data: reformatting for d3.js
  var root = d3
    .stratify()
    .id(function (d) {
      return d.name;
    }) // Name of the entity (column name is name in csv)
    .parentId(function (d) {
      return d.parent;
    })(
    // Name of the parent (column name is parent in csv)
    data
  );
  root.sum(function (d) {
    return +d.value;
  }); // Compute the numeric value for each entity

  // Then d3.treemap computes the position of each element of the hierarchy
  // The coordinates are added to the root object above
  d3.treemap().size([width, height]).padding(10)(root);

  console.log(root.leaves());
  // use this information to add rectangles:
  svg
    .selectAll("rect")
    .data(root.leaves())
    .enter()
    .append("rect")
    .attr("x", function (d) {
      return d.x0;
    })
    .attr("y", function (d) {
      return d.y0;
    })
    .attr("width", function (d) {
      return d.x1 - d.x0;
    })
    .attr("height", function (d) {
      return d.y1 - d.y0;
    })
    .style("stroke", "black")
    .style("fill", "#ffcc99");

  // and to add the text labels
  svg
    .selectAll("text")
    .data(root.leaves())
    .enter()
    .append("text")
    .attr("x", function (d) {
      return d.x0 + 10;
    }) // +10 to adjust position (more right)
    .attr("y", function (d) {
      return d.y0 + 20;
    }) // +20 to adjust position (lower)
    .text(function (d) {
      return d.data.name;
    })
    .attr("font-size", "10px")
    .attr("fill", "black");
});