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@HarryStevens
Last active Jun 11, 2017
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Sankey from CSV III
license: gpl-3.0

Create a Sankey diagram from a CSV file. I got most of this code from d3noob's block, but I added the code to convert the CSV data into the format required by d3-sankey.

In this version, the links are colored as a linear gradient, transitioning from the color of the source to that of the target. In version 1, the links were not colored. In version 2, the links were colored according to this source.

My verdict: A single color is the easiest to read.

source target value
Bob Jimmy 30000000
Joey Bunk 632000000
Joey Lester 100000000
Joey Kima 541000000
Joey Sidnor 7500000
Joey Roland 15000000
Joey Cedric 20000000
Steve Kima 30000000
Steve Cedric 10000000
Ross Jay 15384115
Ross Bunk 21000034
Ross Lester 52563320
Ross Kima 99039298
Ross Phoebe 5910000
Ross Sidnor 18872439
Ross Chandler 6797000
Ross Cedric 13105704
John Bunk 1072500000
John Lester 2500000
John Kima 187500000
John Phoebe 10000000
John Monica 10000000
John Chandler 10000000
John Rachel 10000000
Tim Bunk 20000000
Tim Rachel 10000000
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
body {
margin: 0;
font-family: "Helvetica Neue", sans-serif;
}
.node rect {
cursor: move;
fill-opacity: .9;
shape-rendering: crispEdges;
}
.node text {
pointer-events: none;
text-shadow: 0px 0px 2px #fff;
font-size: .8em;
}
.link {
fill: none;
stroke: #000;
stroke-opacity: .5;
}
.link:hover {
stroke-opacity: 1;
}
</style>
</head>
<body>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="sankey.js"></script>
<script>
// set the dimensions and margins of the graph
var margin = {top: 10, right: 10, bottom: 10, left: 10},
width = window.innerWidth - margin.left - margin.right,
height = window.innerHeight - margin.top - margin.bottom;
// format variables
var formatNumber = d3.format(",.0f"), // zero decimal places
format = function(d) { return "$" + formatNumber(d); },
color = d3.scaleOrdinal(d3.schemeCategory20);
// append the svg object to the body of the page
var svg = d3.select("body").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 + ")");
// Set the sankey diagram properties
var sankey = d3.sankey()
.nodeWidth(10)
.nodePadding(10)
.size([width, height]);
var path = sankey.link();
// defs for the linear gradients
var defs = svg.append("defs");
// load the data
d3.queue()
.defer(d3.csv, "data.csv")
.await(ready);
function ready(error, csv){
// create an array to push all sources and targets, before making them unique
var arr = [];
csv.forEach(function(d){
arr.push(d.source);
arr.push(d.target);
});
// create nodes array
var nodes = arr.filter(onlyUnique).map(function(d,i){
return {
node: i,
name: d
}
});
// create links array
var links = csv.map(function(csv_row){
return {
source: getNode("source"),
target: getNode("target"),
value: +csv_row.value
}
function getNode(type){
return nodes.filter(function(node_object){ return node_object.name == csv_row[type]; })[0].node;
}
});
sankey
.nodes(nodes)
.links(links)
.layout(32);
// add in the links
var link = svg.append("g").selectAll(".link")
.data(links)
.enter().append("path")
.attr("class", "link")
.attr("d", path)
.style("stroke", function(d, i){
// create the gradient
var gradient_id = "gradient-" + i;
var gradient = defs.append("linearGradient")
.attr("id", gradient_id);
gradient.append("stop")
.attr("offset", "5%")
.attr("stop-color", color(d.source.name.replace(/ .*/, "")));
gradient.append("stop")
.attr("offset", "95%")
.attr("stop-color", color(d.target.name.replace(/ .*/, "")));
// TODO: Figure out what the hell is happening with bob and jimmy
return i == 0 ? color(d.source.name.replace(/ .*/, "")) : "url(#" + gradient_id + ")";
// return "url(#" + gradient_id + ")";
})
.style("stroke-width", function(d) { return Math.max(1, d.dy); })
.sort(function(a, b) { return b.dy - a.dy; });
// add the link titles
link.append("title")
.text(function(d) {
return d.source.name + " → " +
d.target.name + "\n" + format(d.value); });
// add in the nodes
var node = svg.append("g").selectAll(".node")
.data(nodes)
.enter().append("g")
.attr("class", "node")
.attr("transform", function(d) {
return "translate(" + d.x + "," + d.y + ")";
})
.call(d3.drag()
.subject(function(d) {
return d;
})
.on("start", function() {
this.parentNode.appendChild(this);
})
.on("drag", dragmove));
// add the rectangles for the nodes
node.append("rect")
.attr("height", function(d) { return d.dy < 0 ? .1 : 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);
});
// add in the title for the nodes
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");
// the function for moving the nodes
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);
}
}
// unique values of an array
function onlyUnique(value, index, self) {
return self.indexOf(value) === index;
}
</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;
};
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 + d.sy + d.dy / 2,
y1 = d.target.y + 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);
});
}
// 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;
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) {
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;
};
@davo
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davo commented Jun 1, 2017

For some reason, the example is not working anymore.

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