Using particles to indicate flow between reservoirs in a sankey diagram. This time with particles moving at varying speeds and maintaining the color of the source node. You can drag the reservoirs (the rectangles) to adjust the path of the flows.
Other examples of sankeys with particles:
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<html lang="en">
<head>
<meta charset="utf-8" />
<title>Sankey Particles</title>
<style>
.node rect {
cursor: move;
fill-opacity: .9;
shape-rendering: crispEdges;
}
.node text {
pointer-events: none;
text-shadow: 0 1px 0 #fff;
}
.link {
fill: none;
stroke: #000;
stroke-opacity: .15;
}
.link:hover {
stroke-opacity: .25;
}
svg {
position: absolute;
}
canvas {
position: absolute;
}
</style>
</head>
<body>
<canvas width="1000" height="1000" ></canvas>
<svg width="1000" height="1000" ></svg>
<script src="https://d3js.org/d3.v3.min.js" charset="utf-8" type="text/javascript"></script>
<script src="d3.sankey.js" charset="utf-8" type="text/javascript"></script>
<script type="text/javascript">
var margin = {top: 1, right: 1, bottom: 6, left: 1},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var formatNumber = d3.format(",.0f"),
format = function(d) { return formatNumber(d) + " TWh"; },
color = d3.scale.category20();
var svg = d3.select("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var sankey = d3.sankey()
.nodeWidth(15)
.nodePadding(10)
.size([width, height]);
var path = sankey.link();
var freqCounter = 1;
d3.json("energy.json", function(energy) {
sankey
.nodes(energy.nodes)
.links(energy.links)
.layout(32);
var link = svg.append("g").selectAll(".link")
.data(energy.links)
.enter().append("path")
.attr("class", "link")
.attr("d", path)
.style("stroke-width", function(d) { return Math.max(1, d.dy); })
.sort(function(a, b) { return b.dy - a.dy; });
link.append("title")
.text(function(d) { return d.source.name + " → " + d.target.name + "\n" + format(d.value); });
var node = svg.append("g").selectAll(".node")
.data(energy.nodes)
.enter().append("g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; })
.call(d3.behavior.drag()
.origin(function(d) { return d; })
.on("dragstart", function() { this.parentNode.appendChild(this); })
.on("drag", dragmove));
node.append("rect")
.attr("height", function(d) { return d.dy; })
.attr("width", sankey.nodeWidth())
.style("fill", function(d) { return d.color = color(d.name.replace(/ .*/, "")); })
.style("stroke", "none")
.append("title")
.text(function(d) { return d.name + "\n" + format(d.value); });
node.append("text")
.attr("x", -6)
.attr("y", function(d) { return d.dy / 2; })
.attr("dy", ".35em")
.attr("text-anchor", "end")
.attr("transform", null)
.text(function(d) { return d.name; })
.filter(function(d) { return d.x < width / 2; })
.attr("x", 6 + sankey.nodeWidth())
.attr("text-anchor", "start");
function dragmove(d) {
d3.select(this).attr("transform", "translate(" + d.x + "," + (d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))) + ")");
sankey.relayout();
link.attr("d", path);
}
var linkExtent = d3.extent(energy.links, function (d) {return d.value});
var frequencyScale = d3.scale.linear().domain(linkExtent).range([0.05,1]);
var particleSize = d3.scale.linear().domain(linkExtent).range([1,5]);
energy.links.forEach(function (link) {
link.freq = frequencyScale(link.value);
link.particleSize = 2;
link.particleColor = d3.scale.linear().domain([0,1])
.range([link.source.color, link.target.color]);
})
var t = d3.timer(tick, 1000);
var particles = [];
function tick(elapsed, time) {
particles = particles.filter(function (d) {return d.current < d.path.getTotalLength()});
d3.selectAll("path.link")
.each(
function (d) {
// if (d.freq < 1) {
for (var x = 0;x<2;x++) {
var offset = (Math.random() - .5) * (d.dy - 4);
if (Math.random() < d.freq) {
var length = this.getTotalLength();
particles.push({link: d, time: elapsed, offset: offset, path: this, length: length, animateTime: length, speed: 0.5 + (Math.random())})
}
}
// }
/* else {
for (var x = 0; x<d.freq; x++) {
var offset = (Math.random() - .5) * d.dy;
particles.push({link: d, time: elapsed, offset: offset, path: this})
}
} */
});
particleEdgeCanvasPath(elapsed);
}
function particleEdgeCanvasPath(elapsed) {
var context = d3.select("canvas").node().getContext("2d")
context.clearRect(0,0,1000,1000);
context.fillStyle = "gray";
context.lineWidth = "1px";
for (var x in particles) {
var currentTime = elapsed - particles[x].time;
// var currentPercent = currentTime / 1000 * particles[x].path.getTotalLength();
particles[x].current = currentTime * 0.15 * particles[x].speed;
var currentPos = particles[x].path.getPointAtLength(particles[x].current);
context.beginPath();
context.fillStyle = particles[x].link.particleColor(0);
context.arc(currentPos.x,currentPos.y + particles[x].offset,particles[x].link.particleSize,0,2*Math.PI);
context.fill();
}
}
});
</script>
</body>
</html>
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js