block by Fil 96be4e4e8106992e32fa4fa253b115d0

Hexagonal Binning in d3v4

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This example shows how to use the d3.hexbin plugin for hexagonal binning. 2,000 random points with a normal distribution are binned into hexagons; color encodes the number of points that fall into each bin. You can also use area encoding. Inspired by earlier work by Zachary Forest Johnson.

forked from mbostock‘s block: Hexagonal Binning

index.html

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

.axis text {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.hexagon {
  fill: none;
  stroke: #000;
  stroke-width: .5px;
}

</style>
<body>
<script src="//d3js.org/d3.v4.min.js"></script>
<script src="d3.hexbin.min.js"></script>
<script>

var margin = {top: 20, right: 20, bottom: 30, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var randomX = d3.randomNormal(width / 2, 80),
    randomY = d3.randomNormal(height / 2, 80),
    points = d3.range(2000).map(function() { return [randomX(), randomY()]; });

var color = d3.scaleLinear()
    .domain([0, 20])
    .range(["white", "steelblue"])
    .interpolate(d3.interpolateLab);

var hexbin = d3.hexbin()
    .size([width, height])
    .radius(20);

var x = d3.scaleIdentity()
    .domain([0, width]);

var y = d3.scaleLinear()
    .domain([0, height])
    .range([height, 0]);

var xAxis = d3.axisBottom()
    .scale(x)
    .tickSize(6, -height);

var yAxis = d3.axisLeft()
    .scale(y)
    .tickSize(6, -width);

var svg = d3.select("body").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 + ")");

svg.append("clipPath")
    .attr("id", "clip")
  .append("rect")
    .attr("class", "mesh")
    .attr("width", width)
    .attr("height", height);

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

svg.append("g")
    .attr("class", "y axis")
    .call(yAxis);

svg.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + height + ")")
    .call(xAxis);

</script>

d3.hexbin.min.js

!function(){d3.hexbin=function(){function u(n){var r={};return n.forEach(function(n,t){var a=s.call(u,n,t)/o,e=Math.round(a),c=h.call(u,n,t)/i-(1&e?.5:0),f=Math.round(c),l=a-e;if(3*Math.abs(l)>1){var v=c-f,g=f+(f>c?-1:1)/2,m=e+(e>a?-1:1),M=c-g,d=a-m;v*v+l*l>M*M+d*d&&(f=g+(1&e?1:-1)/2,e=m)}var j=f+"-"+e,p=r[j];p?p.push(n):(p=r[j]=[n],p.i=f,p.j=e,p.x=(f+(1&e?.5:0))*i,p.y=e*o)}),d3.values(r)}function a(r){var t=0,u=0;return n.map(function(n){var a=Math.sin(n)*r,e=-Math.cos(n)*r,i=a-t,o=e-u;return t=a,u=e,[i,o]})}var e,i,o,c=1,f=1,h=r,s=t;return u.x=function(n){return arguments.length?(h=n,u):h},u.y=function(n){return arguments.length?(s=n,u):s},u.hexagon=function(n){return arguments.length<1&&(n=e),"m"+a(n).join("l")+"z"},u.centers=function(){for(var n=[],r=0,t=!1,u=0;f+e>r;r+=o,t=!t,++u)for(var a=t?i/2:0,h=0;c+i/2>a;a+=i,++h){var s=[a,r];s.i=h,s.j=u,n.push(s)}return n},u.mesh=function(){var n=a(e).slice(0,4).join("l");return u.centers().map(function(r){return"M"+r+"m"+n}).join("")},u.size=function(n){return arguments.length?(c=+n[0],f=+n[1],u):[c,f]},u.radius=function(n){return arguments.length?(e=+n,i=2*e*Math.sin(Math.PI/3),o=1.5*e,u):e},u.radius(1)};var n=d3.range(0,2*Math.PI,Math.PI/3),r=function(n){return n[0]},t=function(n){return n[1]}}();