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Last active May 14, 2019
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d3-plugins sankey cycle support
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="http://d3js.org/d3.v2.js"></script>
<script type="text/javascript" src="./sankey.js"></script>
<title>Sankey Diagram</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: .2;
}
.cycleLink {
fill: #600;
opacity: .2;
stroke: none;
stroke-linejoin: "round";
}
.cycleLink:hover {
opacity: .5;
}
.link:hover {
stroke-opacity: .5;
}
</style>
</head>
<body>
<p>
The chart below is made from randomly generated data
(largely based on <a href="http://bl.ocks.org/cfergus/3956043">http://bl.ocks.org/cfergus/3956043</a>).
If it looks strange, try refresh.
</p>
<p id="chart"></p>
<script>
var margin = {top: 1, right: 1, bottom: 6, left: 1},
width = 960 - margin.left - margin.right,
height = 450 - margin.top - margin.bottom;
var formatNumber = d3.format(",.0f"),
format = function(d) { return formatNumber(d) + " tuples"; },
color = d3.scale.category20();
var sankey = d3.sankey()
.nodeWidth(15)
.nodePadding(10)
.size([width, height]);
var svg = d3.select("#chart").append("svg")
.attr( "preserveAspectRatio", "xMinYMid meet" )
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom);
var rootGraphic = svg
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var path = sankey.link();
function createChart( energy ) {
sankey
.nodes(energy.nodes)
.links(energy.links)
.layout(32);
var allgraphics = svg.append("g").attr("id", "node-and-link-container" );
var link = allgraphics.append("g").attr("id", "link-container")
.selectAll(".link")
.data(energy.links)
.enter().append("path")
.attr("class", function(d) { return (d.causesCycle ? "cycleLink" : "link") })
.attr("d", path)
.sort(function(a, b) { return b.dy - a.dy; })
;
link.filter( function(d) { return !d.causesCycle} )
.style("stroke-width", function(d) { return Math.max(1, d.dy); })
link.append("title")
.text(function(d) { return d.source.name + " -> " + d.target.name + "\n" + format(d.value); });
var node = allgraphics.append("g").attr("id", "node-container")
.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);
}
// I need to learn javascript
var numCycles = 0;
for( var i = 0; i< sankey.links().length; i++ ) {
if( sankey.links()[i].causesCycle ) {
numCycles++;
}
}
var cycleTopMarginSize = (sankey.cycleLaneDistFromFwdPaths() -
( (sankey.cycleLaneNarrowWidth() + sankey.cycleSmallWidthBuffer() ) * numCycles ) )
var horizontalMarginSize = ( sankey.cycleDistFromNode() + sankey.cycleControlPointDist() );
svg = d3.select("#chart").select("svg")
.attr( "viewBox",
"" + (0 - horizontalMarginSize ) + " " // left
+ cycleTopMarginSize + " " // top
+ (960 + horizontalMarginSize * 2 ) + " " // width
+ (500 + (-1 * cycleTopMarginSize)) + " " ); // height
};
function generateRandomData() {
var dataObject = new Object();
var numNodes = Math.floor(10 + 10 * Math.random());
var numLinks = Math.floor(1.25 * numNodes + 10 * Math.random());
// Generate nodes
dataObject.nodes = d3.range(numNodes).map(function (x) {return {name: "Node-" + x};});
// Generate links
dataObject.links = d3.range(numLinks).map(function (x) {
var target = source = Math.floor(Math.random() * numNodes);
while (target== source) {
target = Math.floor(Math.random() * numNodes);
}
return {source: source, target: target, value: 5 + 20 * Math.random()};
});
return dataObject;
}
var energyData = generateRandomData();
createChart( energyData );
</script>
</body>
</html>
d3.sankey = function() {
var sankey = {},
nodeWidth = 24,
nodePadding = 8,
size = [1, 1],
nodes = [],
links = [];
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.layout = function(iterations) {
computeNodeLinks();
computeNodeValues();
computeNodeBreadths();
computeNodeDepths(iterations);
computeLinkDepths();
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 {
xsc = xi(-0.5*curvature);
xtc = xi(1 + 0.5*curvature);
var xm = xi(0.5);
var ym = d3.interpolateNumber(ys, yt)(-.5);
return "M" + xs + "," + ys
+ "C" + xsc + "," + ys
+ " " + xsc + "," + ym
+ " " + xm + "," + ym
+ "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) {
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) {
console.warn('Detected cycles in the graph.');
findAndMarkCycleBreaker(nextNodes);
}
else {
remainingNodes = nextNodes;
++x;
}
}
// Move pure sinks always to the right.
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 makes a cycle with current path.
target = link.target;
if (path.indexOf(target) > -1) {
// Mark this link as a known cycle breaker.
link.cycleBreaker = true;
// Stop further search if we found a cycle breaker.
return link;
}
// Recurse deeper.
path.push(cursorNode);
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();
for (var alpha = 1; iterations > 0; --iterations) {
relaxRightToLeft(alpha *= .99);
resolveCollisions();
relaxLeftToRight(alpha);
resolveCollisions();
}
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 center(link.source) * 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 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;
}
}
// 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;
};
@hamxiaoz

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@hamxiaoz hamxiaoz commented Jan 14, 2018

I got error saying: Uncaught TypeError: sankey.cycleLaneDistFromFwdPaths is not a function.
If you search the code I don't see cycleLaneDistFromFwdPaths is defined anywhere.

UPDATE: I found out I can get those functions from this one: http://bl.ocks.org/cfergus/3956043

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