| license: gpl-3.0 |
This chart shows a histogram of a Bates distribution. The data is randomly generated. The values are then binned at regular intervals using D3’s histogram layout. The x-axis uses a linear scale, such that the tick values appear between bars; this provides better indication that each bar represents the count of values between its surrounding tick values.
See also this histogram of a log-normal distribution of time durations.
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> | |
| .bar rect { | |
| fill: steelblue; | |
| } | |
| .bar text { | |
| fill: #fff; | |
| font: 10px sans-serif; | |
| } | |
| </style> | |
| <svg width="960" height="500"></svg> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var data = d3.range(1000).map(d3.randomBates(10)); | |
| var formatCount = d3.format(",.0f"); | |
| var svg = d3.select("svg"), | |
| margin = {top: 10, right: 30, bottom: 30, left: 30}, | |
| width = +svg.attr("width") - margin.left - margin.right, | |
| height = +svg.attr("height") - margin.top - margin.bottom, | |
| g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")"); | |
| var x = d3.scaleLinear() | |
| .rangeRound([0, width]); | |
| var bins = d3.histogram() | |
| .domain(x.domain()) | |
| .thresholds(x.ticks(20)) | |
| (data); | |
| var y = d3.scaleLinear() | |
| .domain([0, d3.max(bins, function(d) { return d.length; })]) | |
| .range([height, 0]); | |
| var bar = g.selectAll(".bar") | |
| .data(bins) | |
| .enter().append("g") | |
| .attr("class", "bar") | |
| .attr("transform", function(d) { return "translate(" + x(d.x0) + "," + y(d.length) + ")"; }); | |
| bar.append("rect") | |
| .attr("x", 1) | |
| .attr("width", x(bins[0].x1) - x(bins[0].x0) - 1) | |
| .attr("height", function(d) { return height - y(d.length); }); | |
| bar.append("text") | |
| .attr("dy", ".75em") | |
| .attr("y", 6) | |
| .attr("x", (x(bins[0].x1) - x(bins[0].x0)) / 2) | |
| .attr("text-anchor", "middle") | |
| .text(function(d) { return formatCount(d.length); }); | |
| g.append("g") | |
| .attr("class", "axis axis--x") | |
| .attr("transform", "translate(0," + height + ")") | |
| .call(d3.axisBottom(x)); | |
| </script> |