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Sankey cycle test
sankeyDraw(
{
'nodes': [
{name: "a"},
{name: "b"},
{name: "c"},
{name: "d"},
{name: "e"},
{name: "f"},
{name: "g"},
{name: "h"},
{name: "i"},
{name: "j"},
{name: "k"},
{name: "l"},
{name: "m"},
{name: "n"},
{name: "o"},
{name: "p"},
{name: "q"},
{name: "r"},
{name: "s"},
{name: "t"},
{name: "u"},
{name: "v"},
{name: "w"},
{name: "x"},
{name: "y"},
{name: "z"},
{name: "aa"},
{name: "ab"},
{name: "ac"},
{name: "ad"},
{name: "ae"},
{name: "af"},
{name: "ag"},
{name: "ah"},
{name: "ai"},
{name: "aj"},
{name: "ak"},
{name: "al"},
{name: "am"},
{name: "an"},
{name: "ao"},
{name: "ap"},
{name: "aq"},
{name: "ar"},
{name: "as"},
{name: "at"},
{name: "au"},
{name: "av"},
{name: "aw"},
{name: "ax"}
],
'links': [
{"source": 1, "target": 2, "value": 74},
{"source": 2, "target": 3, "value": 64},
{"source": 2, "target": 4, "value": 46},
{"source": 4, "target": 5, "value": 45},
{"source": 5, "target": 6, "value": 45},
{"source": 7, "target": 8, "value": 45},
{"source": 8, "target": 9, "value": 65},
{"source": 10, "target": 11, "value": 42},
{"source": 12, "target": 13, "value": 20},
{"source": 12, "target": 14, "value": 32},
{"source": 14, "target": 15, "value": 42},
{"source": 12, "target": 16, "value": 427},
{"source": 16, "target": 17, "value": 111},
{"source": 16, "target": 19, "value": 304},
{"source": 19, "target": 20, "value": 133},
{"source": 19, "target": 21, "value": 155},
{"source": 21, "target": 22, "value": 155},
{"source": 22, "target": 23, "value": 155},
{"source": 19, "target": 24, "value": 62},
{"source": 26, "target": 27, "value": 51},
{"source": 26, "target": 28, "value": 552},
{"source": 28, "target": 29, "value": 552},
{"source": 29, "target": 30, "value": 99},
{"source": 29, "target": 31, "value": 443},
{"source": 31, "target": 32, "value": 431},
{"source": 32, "target": 33, "value": 431},
{"source": 26, "target": 34, "value": 73},
{"source": 34, "target": 35, "value": 34},
{"source": 35, "target": 36, "value": 52},
{"source": 26, "target": 37, "value": 607},
{"source": 37, "target": 38, "value": 138},
{"source": 37, "target": 39, "value": 75},
{"source": 37, "target": 40, "value": 456},
{"source": 40, "target": 41, "value": 181},
{"source": 40, "target": 42, "value": 250},
{"source": 40, "target": 43, "value": 34},
{"source": 43, "target": 44, "value": 45},
{"source": 44, "target": 45, "value": 74},
{"source": 42, "target": 46, "value": 249},
{"source": 46, "target": 47, "value": 249},
{"source": 40, "target": 48, "value": 73},
{"source": 48, "target": 49, "value": 53},
{"source": 48, "target": 12, "value": 43},
{"source": 16, "target": 3, "value": 43},
{"source": 46, "target": 33, "value": 43},
{"source": 26, "target": 8, "value": 63},
{"source": 31, "target": 16, "value": 43},
{"source": 15, "target": 7, "value": 43},
{"source": 25, "target": 14, "value": 80},
{"source": 16, "target": 48, "value": 80},
{"source": 15, "target": 12, "value": 100},
{"source": 38, "target": 39, "value": 53},
{"source": 39, "target": 37, "value": 54},
{"source": 33, "target": 41, "value": 80},
{"source": 32, "target": 28, "value": 235},
{"source": 14, "target": 1, "value": 34},
{"source": 0, "target": 10, "value": 34},
{"source": 25, "target": 0, "value": 60},
{"source": 41, "target": 47, "value": 60},
{"source": 47, "target": 3, "value": 23},
{"source": 41, "target": 40, "value": 45},
{"source": 6, "target": 18, "value": 90}
],
'sinksRight': false
}
);
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Sankey Diagram Example</title>
<style>
body {
font-family: sans-serif;
}
.node rect {
fill-opacity: .9;
shape-rendering: crispEdges;
}
.link {
fill: none;
stroke: #024;
stroke-opacity: .2;
}
.link:hover {
stroke-opacity: .5;
}
.link.backwards {
stroke: #402;
stroke-dasharray: 9,1;
}
</style>
</head>
<body>
<div id="data-set-select"></div>
<div id="chart"></div>
<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
<script src="sankey.js"></script>
<script>
// Some setup stuff.
var margin = {top: 20, right: 20, bottom: 20, left: 20};
var width = 960 - margin.left - margin.right;
var height = 500 - margin.top - margin.bottom;
var color = d3.scale.category20();
// SVG (group) to draw in.
var svg = d3.select("#chart").append("svg")
.attr({
width: width + margin.left + margin.right,
height: height + margin.top + margin.bottom
})
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var linksGroup = svg.append("g").attr('class', 'links');
var nodesGroup = svg.append("g").attr('class', 'nodes');
// Set up Sankey object.
var sankey = d3.sankey()
.nodeWidth(30)
.nodePadding(5)
.size([width, height]);
// Get path data generator
var path = sankey.link();
// Callback to draw on a data set.
function sankeyDraw(data) {
sankey.nodes(data.nodes)
.links(data.links)
.sinksRight('sinksRight' in data ? data.sinksRight : true)
.layout(32);
// Draw the links.
var links = linksGroup.selectAll('.link').data(data.links);
// Enter
links.enter()
.append("path")
.attr('class', 'link');
// Enter + Update
links.attr('d', path)
.style("stroke-width", function (d) {
return Math.max(1, d.dy);
});
links.classed('backwards', function (d) { return d.target.x < d.source.x; });
links.append("title")
.text(function (d) {
return d.source.name + " to " + d.target.name + " = " + d.value;
});
// Exit
links.exit().remove();
// Draw the nodes.
var nodes = nodesGroup.selectAll('.node').data(data.nodes);
// Enter
var nodesEnterSelection = nodes.enter()
.append("g")
.attr('class', 'node');
nodesEnterSelection.append("rect")
.attr('width', sankey.nodeWidth())
.append("title");
nodesEnterSelection.append("text")
.attr('x', sankey.nodeWidth() / 2)
.attr('dy', ".35em")
.attr("text-anchor", "middle")
.attr('transform', null);
// Enter + Update
nodes
.attr('transform', function (d) {
return "translate(" + d.x + "," + d.y + ")";
});
nodes.select('rect')
.attr('height', function (d) {
return d.dy;
})
.style('fill', function (d) {
return d.color = color(d.name.replace(/ .*/, ""));
})
.style('stroke', function (d) {
return d3.rgb(d.color).darker(2);
});
nodes.select('rect').select('title')
.text(function (d) {
return d.name;
});
nodes.select('text')
.attr('y', function (d) {
return d.dy / 2;
})
.text(function (d) {
return d.name;
});
// Exit
nodes.exit().remove();
}
</script>
<script src="data07-big-with-cycle.js"></script>
</body>
</html>
d3.sankey = function() {
var sankey = {},
nodeWidth = 24,
nodePadding = 8,
size = [1, 1],
nodes = [],
links = [],
sinksRight = true;
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.sinksRight = function (_) {
if (!arguments.length) return sinksRight;
sinksRight = _;
return sankey;
};
sankey.layout = function(iterations) {
computeNodeLinks();
computeNodeValues();
computeNodeBreadths();
computeNodeDepths(iterations);
return sankey;
};
sankey.relayout = function() {
computeLinkDepths();
return sankey;
};
// SVG path data generator, to be used as "d" attribute on "path" element selection.
sankey.link = function() {
var curvature = .5;
function link(d) {
var xs = d.source.x + d.source.dx,
xt = d.target.x,
xi = d3.interpolateNumber(xs, xt),
xsc = xi(curvature),
xtc = xi(1 - curvature),
ys = d.source.y + d.sy + d.dy / 2,
yt = d.target.y + d.ty + d.dy / 2;
if (!d.cycleBreaker) {
return "M" + xs + "," + ys
+ "C" + xsc + "," + ys
+ " " + xtc + "," + yt
+ " " + xt + "," + yt;
} else {
var xdelta = (1.5 * d.dy + 0.05 * Math.abs(xs - xt));
xsc = xs + xdelta;
xtc = xt - xdelta;
var xm = xi(0.5);
var ym = d3.interpolateNumber(ys, yt)(0.5);
var ydelta = (2 * d.dy + 0.1 * Math.abs(xs - xt) + 0.1 * Math.abs(ys - yt)) * (ym < (size[1] / 2) ? -1 : 1);
return "M" + xs + "," + ys
+ "C" + xsc + "," + ys
+ " " + xsc + "," + (ys + ydelta)
+ " " + xm + "," + (ym + ydelta)
+ "S" + xtc + "," + yt
+ " " + xt + "," + yt;
}
}
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) {
// Links that have this node as source.
node.sourceLinks = [];
// Links that have this node as target.
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);
});
}
// Compute the value (size) of each node by summing the associated links.
function computeNodeValues() {
nodes.forEach(function(node) {
node.value = Math.max(
d3.sum(node.sourceLinks, 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;
// Work from left to right.
// Keep updating the breath (x-position) of nodes that are target of recently updated nodes.
while (remainingNodes.length && x < nodes.length) {
nextNodes = [];
remainingNodes.forEach(function(node) {
node.x = x;
node.dx = nodeWidth;
node.sourceLinks.forEach(function(link) {
if (nextNodes.indexOf(link.target) < 0 && !link.cycleBreaker) {
nextNodes.push(link.target);
}
});
});
if (nextNodes.length == remainingNodes.length) {
// There must be a cycle here. Let's search for a link that breaks it.
findAndMarkCycleBreaker(nextNodes);
// Start over.
// TODO: make this optional?
return computeNodeBreadths();
}
else {
remainingNodes = nextNodes;
++x;
}
}
// Optionally move pure sinks always to the right.
if (sinksRight) {
moveSinksRight(x);
}
scaleNodeBreadths((size[0] - nodeWidth) / (x - 1));
}
// Find a link that breaks a cycle in the graph (if any).
function findAndMarkCycleBreaker(nodes) {
// Go through all nodes from the given subset and traverse links searching for cycles.
var link;
for (var n=nodes.length - 1; n >= 0; n--) {
link = depthFirstCycleSearch(nodes[n], []);
if (link) {
return link;
}
}
// Depth-first search to find a link that is part of a cycle.
function depthFirstCycleSearch(cursorNode, path) {
var target, link;
for (var n = cursorNode.sourceLinks.length - 1; n >= 0; n--) {
link = cursorNode.sourceLinks[n];
if (link.cycleBreaker) {
// Skip already known cycle breakers.
continue;
}
// Check if target of link makes a cycle in current path.
target = link.target;
for (var l = 0; l < path.length; l++) {
if (path[l].source == target) {
// We found a cycle. Search for weakest link in cycle
var weakest = link;
for (; l < path.length; l++) {
if (path[l].value < weakest.value) {
weakest = path[l];
}
}
// Mark weakest link as (known) cycle breaker and abort search.
weakest.cycleBreaker = true;
return weakest;
}
}
// Recurse deeper.
path.push(link);
link = depthFirstCycleSearch(target, path);
path.pop();
// Stop further search if we found a cycle breaker.
if (link) {
return link;
}
}
}
}
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;
});
}
// Compute the depth (y-position) for each node.
function computeNodeDepths(iterations) {
// Group nodes by breath.
var nodesByBreadth = d3.nest()
.key(function(d) { return d.x; })
.sortKeys(d3.ascending)
.entries(nodes)
.map(function(d) { return d.values; });
//
initializeNodeDepth();
resolveCollisions();
computeLinkDepths();
for (var alpha = 1; iterations > 0; --iterations) {
relaxRightToLeft(alpha *= .99);
resolveCollisions();
computeLinkDepths();
relaxLeftToRight(alpha);
resolveCollisions();
computeLinkDepths();
}
function initializeNodeDepth() {
// Calculate vertical scaling factor.
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) {
// Value-weighted average of the y-position of source node centers linked to this node.
var y = d3.sum(node.targetLinks, weightedSource) / d3.sum(node.targetLinks, value);
node.y += (y - center(node)) * alpha;
}
});
});
function weightedSource(link) {
return (link.source.y + link.sy + link.dy / 2) * link.value;
}
}
function relaxRightToLeft(alpha) {
nodesByBreadth.slice().reverse().forEach(function(nodes) {
nodes.forEach(function(node) {
if (node.sourceLinks.length) {
// Value-weighted average of the y-positions of target nodes linked to this node.
var y = d3.sum(node.sourceLinks, weightedTarget) / d3.sum(node.sourceLinks, value);
node.y += (y - center(node)) * alpha;
}
});
});
function weightedTarget(link) {
return (link.target.y + link.ty + link.dy / 2) * 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;
}
}
// Compute y-offset of the source endpoint (sy) and target endpoints (ty) of links,
// relative to the source/target node's y-position.
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;
}
}
// Y-position of the middle of a node.
function center(node) {
return node.y + node.dy / 2;
}
// Value property accessor.
function value(x) {
return x.value;
}
return sankey;
};
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