| license: gpl-3.0 |
For continuous data such as time series, a streamgraph can be used in place of stacked bars. This example also demonstrates path transitions to interpolate between different layouts. Streamgraph algorithm, colors, and data generation inspired by Byron and Wattenberg.
forked from mbostock's block: Streamgraph
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <title>Streamgraph</title> | |
| <style> | |
| body { | |
| font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; | |
| margin: auto; | |
| position: relative; | |
| width: 960px; | |
| } | |
| button { | |
| position: absolute; | |
| right: 10px; | |
| top: 10px; | |
| } | |
| </style> | |
| <button onclick="transition()">Update</button> | |
| <script src="//d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var n = 20, // number of layers | |
| m = 20, // number of samples per layer | |
| stack = d3.stack() | |
| .keys(d3.range(n)) | |
| .offset(d3.stackOffsetWiggle), | |
| layers0 = stack(d3.range(n) | |
| .reduce(function(last, layerIdx) { | |
| var layer = bumpLayer(m); | |
| return last.map( | |
| function(v, i){ v[layerIdx] = layer[i].y; return v;} | |
| ); | |
| }, Array(m).fill({}))), | |
| layers1 = stack(d3.range(n) | |
| .reduce(function(last, layerIdx) { | |
| var layer = bumpLayer(m); | |
| return last.map( | |
| function(v, i){ v[layerIdx] = layer[i].y; return v;} | |
| ); | |
| }, Array(m).fill({}))); | |
| var width = 960; | |
| var height = 500; | |
| var x = d3.scaleLinear() | |
| .domain([0, m - 1]) | |
| .range([0, width]); | |
| var y = d3.scaleLinear() | |
| .domain([ | |
| 0, | |
| d3.max(layers0.concat(layers1), | |
| function(layer) { | |
| return d3.max(layer, function(d){ return d[1];}); | |
| }) | |
| ]) | |
| .range([height, 0]); | |
| var color = d3.scaleLinear() | |
| .range(["#aad", "#556"]); | |
| var area = d3.area() | |
| .x(function(d, i) { return x(i); }) | |
| .y0(function(d) { return y(d[0]); }) | |
| .y1(function(d) { return y(d[1]); }) | |
| .curve(d3.curveBasis);; | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| svg.selectAll("path") | |
| .data(layers0) | |
| .enter().append("path") | |
| .attr("d", area) | |
| .style("fill", function() { return color(Math.random()); }); | |
| function transition() { | |
| d3.selectAll("path") | |
| .data(function() { | |
| var d = layers1; | |
| layers1 = layers0; | |
| return layers0 = d; | |
| }) | |
| .transition() | |
| .duration(2500) | |
| .attr("d", area); | |
| } | |
| // Inspired by Lee Byron's test data generator. | |
| function bumpLayer(n) { | |
| function bump(a) { | |
| var x = 1 / (.1 + Math.random()), | |
| y = 2 * Math.random() - .5, | |
| z = 10 / (.1 + Math.random()); | |
| for (var i = 0; i < n; i++) { | |
| var w = (i / n - y) * z; | |
| a[i] += x * Math.exp(-w * w); | |
| } | |
| } | |
| var a = [], i; | |
| for (i = 0; i < n; ++i) a[i] = 0; | |
| for (i = 0; i < 5; ++i) bump(a); | |
| return a.map(function(d, i) { return {y: Math.max(0, d)}; }); | |
| } | |
| </script> |