// set the dimensions and margins of the graph
var margin = {top: 10, right: 30, bottom: 30, left: 40},
    width = 460 - margin.left - margin.right,
    height = 400 - 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("https://raw.githubusercontent.com/holtzy/D3-graph-gallery/master/DATA/data_for_density2d.csv", function(data) {

// Add X axis
  var x = d3.scaleLinear()
    .domain([5, 18])
    .range([ 0, width ]);
  svg.append("g")
    .attr("transform", "translate(0," + height + ")")
    .call(d3.axisBottom(x));

// Add Y axis
  var y = d3.scaleLinear()
    .domain([5, 20])
    .range([ height, 0 ]);
  svg.append("g")
    .call(d3.axisLeft(y));

// Reformat the data: d3.hexbin() needs a specific format
  var inputForHexbinFun = []
  data.forEach(function(d) {
    inputForHexbinFun.push( [x(d.x), y(d.y)] )  // Note that we had the transform value of X and Y !
  })

// Prepare a color palette
  var color = d3.scaleLinear()
      .domain([0, 600]) // Number of points in the bin?
      .range(["transparent",  "#69b3a2"])

// Compute the hexbin data
  var hexbin = d3.hexbin()
    .radius(9) // size of the bin in px
    .extent([ [0, 0], [width, height] ])

// Plot the hexbins
  svg.append("clipPath")
      .attr("id", "clip")
    .append("rect")
      .attr("width", width)
      .attr("height", height)

svg.append("g")
    .attr("clip-path", "url(#clip)")
    .selectAll("path")
    .data( hexbin(inputForHexbinFun) )
    .enter().append("path")
      .attr("d", hexbin.hexagon())
      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; })
      .attr("fill", function(d) { return color(d.length); })
      .attr("stroke", "black")
      .attr("stroke-width", "0.1")
})

Liveweave: Generative AI Web Editor & HTML/CSS/JS Playground