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@billierinaldi
Created September 25, 2012 02:11
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Overlapping Sankey links
{"nodes":[
{"name":"Agricultural 'waste'"},
{"name":"Bio-conversion"},
{"name":"Liquid"},
{"name":"Losses"},
{"name":"Solid"},
{"name":"Gas"},
{"name":"Biofuel imports"},
{"name":"Biomass imports"},
{"name":"Coal imports"},
{"name":"Coal"},
{"name":"Coal reserves"},
{"name":"District heating"},
{"name":"Industry"},
{"name":"Heating and cooling - commercial"},
{"name":"Heating and cooling - homes"},
{"name":"Electricity grid"},
{"name":"Over generation / exports"},
{"name":"H2 conversion"},
{"name":"Road transport"},
{"name":"Agriculture"},
{"name":"Rail transport"},
{"name":"Lighting & appliances - commercial"},
{"name":"Lighting & appliances - homes"},
{"name":"Gas imports"},
{"name":"Ngas"},
{"name":"Gas reserves"},
{"name":"Thermal generation"},
{"name":"Geothermal"},
{"name":"H2"},
{"name":"Hydro"},
{"name":"International shipping"},
{"name":"Domestic aviation"},
{"name":"International aviation"},
{"name":"National navigation"},
{"name":"Marine algae"},
{"name":"Nuclear"},
{"name":"Oil imports"},
{"name":"Oil"},
{"name":"Oil reserves"},
{"name":"Other waste"},
{"name":"Pumped heat"},
{"name":"Solar PV"},
{"name":"Solar Thermal"},
{"name":"Solar"},
{"name":"Tidal"},
{"name":"UK land based bioenergy"},
{"name":"Wave"},
{"name":"Wind"}
],
"links":[
{"source":0,"target":1,"value":124.729},
{"source":1,"target":2,"value":0.597},
{"source":1,"target":3,"value":26.862},
{"source":1,"target":4,"value":280.322},
{"source":1,"target":5,"value":81.144},
{"source":6,"target":2,"value":35},
{"source":7,"target":4,"value":35},
{"source":8,"target":9,"value":11.606},
{"source":10,"target":9,"value":63.965},
{"source":9,"target":4,"value":75.571},
{"source":11,"target":12,"value":10.639},
{"source":11,"target":13,"value":22.505},
{"source":11,"target":14,"value":46.184},
{"source":15,"target":16,"value":104.453},
{"source":15,"target":14,"value":113.726},
{"source":15,"target":17,"value":27.14},
{"source":15,"target":12,"value":342.165},
{"source":15,"target":18,"value":37.797},
{"source":15,"target":19,"value":4.412},
{"source":15,"target":13,"value":40.858},
{"source":15,"target":3,"value":56.691},
{"source":15,"target":20,"value":7.863},
{"source":15,"target":21,"value":90.008},
{"source":15,"target":22,"value":93.494},
{"source":23,"target":24,"value":40.719},
{"source":25,"target":24,"value":82.233},
{"source":5,"target":13,"value":0.129},
{"source":5,"target":3,"value":1.401},
{"source":5,"target":26,"value":151.891},
{"source":5,"target":19,"value":2.096},
{"source":5,"target":12,"value":48.58},
{"source":27,"target":15,"value":7.013},
{"source":17,"target":28,"value":20.897},
{"source":17,"target":3,"value":6.242},
{"source":28,"target":18,"value":20.897},
{"source":29,"target":15,"value":6.995},
{"source":2,"target":12,"value":121.066},
{"source":2,"target":30,"value":128.69},
{"source":2,"target":18,"value":135.835},
{"source":2,"target":31,"value":14.458},
{"source":2,"target":32,"value":206.267},
{"source":2,"target":19,"value":3.64},
{"source":2,"target":33,"value":33.218},
{"source":2,"target":20,"value":4.413},
{"source":34,"target":1,"value":4.375},
{"source":24,"target":5,"value":122.952},
{"source":35,"target":26,"value":839.978},
{"source":36,"target":37,"value":504.287},
{"source":38,"target":37,"value":107.703},
{"source":37,"target":2,"value":611.99},
{"source":39,"target":4,"value":56.587},
{"source":39,"target":1,"value":77.81},
{"source":40,"target":14,"value":193.026},
{"source":40,"target":13,"value":70.672},
{"source":41,"target":15,"value":59.901},
{"source":42,"target":14,"value":19.263},
{"source":43,"target":42,"value":19.263},
{"source":43,"target":41,"value":59.901},
{"source":4,"target":19,"value":0.882},
{"source":4,"target":26,"value":400.12},
{"source":4,"target":12,"value":46.477},
{"source":26,"target":15,"value":525.531},
{"source":26,"target":3,"value":787.129},
{"source":26,"target":11,"value":79.329},
{"source":44,"target":15,"value":9.452},
{"source":45,"target":1,"value":182.01},
{"source":46,"target":15,"value":19.013},
{"source":47,"target":15,"value":289.366}
]}
<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>Sankey Diagram</title>
<style>
@import url(http://bost.ocks.org/mike/style.css?20120521);
#chart {
height: 500px;
}
.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: .2;
}
.link:hover {
stroke-opacity: .5;
}
</style>
<body>
<h1><a href="http://bost.ocks.org/mike/sankey/">Original</a></h1>
<p id="chart1">
<h1>Overlapping Links at Targets</h1>
<p id="chart2">
<h1>Overlapping Links at Sources</h1>
<p id="chart3">
<h1>Overlapping at Sources and Targets</h1>
<p id="chart4">
<script src="http://d3js.org/d3.v2.js"></script>
<script src="sankey.js"></script>
<script>
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();
function addSankey(overlapSources,overlapTargets,parent) {
var svg = d3.select("#"+parent).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 + ")");
var sankey = d3.sankey()
.nodeWidth(15)
.nodePadding(10)
.size([width, height])
.overlapLinksAtSources(overlapSources)
.overlapLinksAtTargets(overlapTargets);
var path = sankey.link();
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", function(d) { return d3.rgb(d.color).darker(2); })
.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);
}
});
}
addSankey(false,false,"chart1");
addSankey(false,true,"chart2");
addSankey(true,false,"chart3");
addSankey(true,true,"chart4");
</script>
</html>
d3.sankey = function() {
var sankey = {},
nodeWidth = 24,
nodePadding = 8,
size = [1, 1],
nodes = [],
links = [],
overlapLinksAtSources = false,
overlapLinksAtTargets = false,
minValue = 1;
sankey.nodeWidth = function(_) {
if (!arguments.length) return nodeWidth;
nodeWidth = +_;
return sankey;
};
sankey.nodePadding = function(_) {
if (!arguments.length) return nodePadding;
nodePadding = +_;
return sankey;
};
sankey.nodes = function(_) {
if (!arguments.length) return nodes;
nodes = _;
return sankey;
};
sankey.links = function(_) {
if (!arguments.length) return links;
links = _;
return sankey;
};
sankey.size = function(_) {
if (!arguments.length) return size;
size = _;
return sankey;
};
sankey.overlapLinksAtSources = function(_) {
if (!arguments.length) return overlapLinksAtSources;
overlapLinksAtSources = _;
return sankey;
};
sankey.overlapLinksAtTargets = function(_) {
if (!arguments.length) return overlapLinksAtTargets;
overlapLinksAtTargets = _;
return sankey;
};
sankey.minValue = function(_) {
if (!arguments.length) return minValue;
minValue = _;
return sankey;
};
sankey.layout = function(iterations) {
computeNodeLinks();
computeNodeValues();
computeNodeBreadths();
computeNodeDepths(iterations);
computeLinkDepths();
return sankey;
};
sankey.relayout = function() {
computeLinkDepths();
return sankey;
};
sankey.link = function() {
var curvature = .5;
function link(d) {
var x0 = d.source.x + d.source.dx,
x1 = d.target.x,
xi = d3.interpolateNumber(x0, x1),
x2 = xi(curvature),
x3 = xi(1 - curvature),
y0 = d.source.y + (overlapLinksAtSources ? 0 : d.sy) + d.dy / 2,
y1 = d.target.y + (overlapLinksAtTargets ? 0 : d.ty) + d.dy / 2;
return "M" + x0 + "," + y0
+ "C" + x2 + "," + y0
+ " " + x3 + "," + y1
+ " " + x1 + "," + y1;
}
link.curvature = function(_) {
if (!arguments.length) return curvature;
curvature = +_;
return link;
};
return link;
};
// Populate the sourceLinks and targetLinks for each node.
// Also, if the source and target are not objects, assume they are indices.
function computeNodeLinks() {
nodes.forEach(function(node) {
node.sourceLinks = [];
node.targetLinks = [];
});
links.forEach(function(link) {
var source = link.source,
target = link.target;
if (typeof source === "number") source = link.source = nodes[link.source];
if (typeof target === "number") target = link.target = nodes[link.target];
source.sourceLinks.push(link);
target.targetLinks.push(link);
if ("value" in link)
link.value = Math.max(link.value, minValue);
else
link.value = minValue;
});
}
// Compute the value (size) of each node by summing the associated links.
function computeNodeValues() {
nodes.forEach(function(node) {
if ("value" in node)
node.value = Math.max(node.value, minValue);
else
node.value = minValue;
if (node.sourceLinks.length > 0) {
if (overlapLinksAtSources)
node.value = Math.max(node.value, d3.max(node.sourceLinks, value));
else
node.value = Math.max(node.value, d3.sum(node.sourceLinks, value));
}
if (node.targetLinks.length > 0) {
if (overlapLinksAtTargets)
node.value = Math.max(node.value, d3.max(node.targetLinks, value));
else
node.value = Math.max(node.value, d3.sum(node.targetLinks, value));
}
});
}
// Iteratively assign the breadth (x-position) for each node.
// Nodes are assigned the maximum breadth of incoming neighbors plus one;
// nodes with no incoming links are assigned breadth zero, while
// nodes with no outgoing links are assigned the maximum breadth.
function computeNodeBreadths() {
var remainingNodes = nodes,
nextNodes,
x = 0;
while (remainingNodes.length) {
nextNodes = [];
remainingNodes.forEach(function(node) {
node.x = x;
node.dx = nodeWidth;
node.sourceLinks.forEach(function(link) {
nextNodes.push(link.target);
});
});
remainingNodes = nextNodes;
++x;
}
//
moveSinksRight(x);
scaleNodeBreadths((size[0] - nodeWidth) / (x - 1));
}
function moveSourcesRight() {
nodes.forEach(function(node) {
if (!node.targetLinks.length) {
node.x = d3.min(node.sourceLinks, function(d) { return d.target.x; }) - 1;
}
});
}
function moveSinksRight(x) {
nodes.forEach(function(node) {
if (!node.sourceLinks.length) {
node.x = x - 1;
}
});
}
function scaleNodeBreadths(kx) {
nodes.forEach(function(node) {
node.x *= kx;
});
}
function computeNodeDepths(iterations) {
var nodesByBreadth = d3.nest()
.key(function(d) { return d.x; })
.sortKeys(d3.ascending)
.entries(nodes)
.map(function(d) { return d.values; });
//
initializeNodeDepth();
resolveCollisions();
for (var alpha = 1; iterations > 0; --iterations) {
relaxRightToLeft(alpha *= .99);
resolveCollisions();
relaxLeftToRight(alpha);
resolveCollisions();
}
function initializeNodeDepth() {
var ky = d3.min(nodesByBreadth, function(nodes) {
return (size[1] - (nodes.length - 1) * nodePadding) / d3.sum(nodes, value);
});
nodesByBreadth.forEach(function(nodes) {
nodes.forEach(function(node, i) {
node.y = i;
node.dy = node.value * ky;
});
});
links.forEach(function(link) {
link.dy = link.value * ky;
});
}
function relaxLeftToRight(alpha) {
nodesByBreadth.forEach(function(nodes, breadth) {
nodes.forEach(function(node) {
if (node.targetLinks.length) {
var y = d3.sum(node.targetLinks, weightedSource) / d3.sum(node.targetLinks, value);
node.y += (y - center(node)) * alpha;
}
});
});
function weightedSource(link) {
return center(link.source) * link.value;
}
}
function relaxRightToLeft(alpha) {
nodesByBreadth.slice().reverse().forEach(function(nodes) {
nodes.forEach(function(node) {
if (node.sourceLinks.length) {
var y = d3.sum(node.sourceLinks, weightedTarget) / d3.sum(node.sourceLinks, value);
node.y += (y - center(node)) * alpha;
}
});
});
function weightedTarget(link) {
return center(link.target) * link.value;
}
}
function resolveCollisions() {
nodesByBreadth.forEach(function(nodes) {
var node,
dy,
y0 = 0,
n = nodes.length,
i;
// Push any overlapping nodes down.
nodes.sort(ascendingDepth);
for (i = 0; i < n; ++i) {
node = nodes[i];
dy = y0 - node.y;
if (dy > 0) node.y += dy;
y0 = node.y + node.dy + nodePadding;
}
// If the bottommost node goes outside the bounds, push it back up.
dy = y0 - nodePadding - size[1];
if (dy > 0) {
y0 = node.y -= dy;
// Push any overlapping nodes back up.
for (i = n - 2; i >= 0; --i) {
node = nodes[i];
dy = node.y + node.dy + nodePadding - y0;
if (dy > 0) node.y -= dy;
y0 = node.y;
}
}
});
}
function ascendingDepth(a, b) {
return a.y - b.y;
}
}
function computeLinkDepths() {
nodes.forEach(function(node) {
node.sourceLinks.sort(ascendingTargetDepth);
node.targetLinks.sort(ascendingSourceDepth);
});
nodes.forEach(function(node) {
var sy = 0, ty = 0;
node.sourceLinks.forEach(function(link) {
link.sy = sy;
sy += link.dy;
});
node.targetLinks.forEach(function(link) {
link.ty = ty;
ty += link.dy;
});
});
function ascendingSourceDepth(a, b) {
return a.source.y - b.source.y;
}
function ascendingTargetDepth(a, b) {
return a.target.y - b.target.y;
}
}
function center(node) {
return node.y + node.dy / 2;
}
function value(link) {
return link.value;
}
return sankey;
};
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