jkz/README.md

## README.md

      
    Raw
  

              README.md
            
          
    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.

  
## index.html
<!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="http://d3js.org/d3.v3.min.js"></script>
<script>

var n = 20, // number of layers
    m = 200, // number of samples per layer
    stack = d3.layout.stack().offset("wiggle"),
    layers0 = stack(d3.range(n).map(function() { return bumpLayer(m); })),
    layers1 = stack(d3.range(n).map(function() { return bumpLayer(m); }));

var width = 960,
    height = 500;

var x = d3.scale.linear()
    .domain([0, m - 1])
    .range([0, width]);

var y = d3.scale.linear()
    .domain([0, d3.max(layers0.concat(layers1), function(layer) { return d3.max(layer, function(d) { return d.y0 + d.y; }); })])
    .range([height, 0]);

var color = d3.scale.linear()
    .range(["#aad", "#556"]);

var area = d3.svg.area()
    .x(function(d) { return x(d.x); })
    .y0(function(d) { return y(d.y0); })
    .y1(function(d) { return y(d.y0 + d.y); });

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 {x: i, y: Math.max(0, d)}; });
}

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	<!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="http://d3js.org/d3.v3.min.js"></script>
	<script>

	var n = 20, // number of layers
	m = 200, // number of samples per layer
	stack = d3.layout.stack().offset("wiggle"),
	layers0 = stack(d3.range(n).map(function() { return bumpLayer(m); })),
	layers1 = stack(d3.range(n).map(function() { return bumpLayer(m); }));

	var width = 960,
	height = 500;

	var x = d3.scale.linear()
	.domain([0, m - 1])
	.range([0, width]);

	var y = d3.scale.linear()
	.domain([0, d3.max(layers0.concat(layers1), function(layer) { return d3.max(layer, function(d) { return d.y0 + d.y; }); })])
	.range([height, 0]);

	var color = d3.scale.linear()
	.range(["#aad", "#556"]);

	var area = d3.svg.area()
	.x(function(d) { return x(d.x); })
	.y0(function(d) { return y(d.y0); })
	.y1(function(d) { return y(d.y0 + d.y); });

	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 {x: i, y: Math.max(0, d)}; });
	}

	</script>