This simply forks the d3noob example to allow a csv as the data source. I am sure that this is probably the ugliest way to do it, but it does work. Please let me know if you have any comments.
This is an example of a Sankey diagram made using d3.js and the sankey plugin.
It has a point of differenc from other Sankey diagrams I have seen in that the nodes can be moved horizontally and vertically.
A description of how it was put together and techniques for implimenting Sankey diagrams in general with d3.js can be found at d3noob.org or you can download the full text in the D3 Tips and Tricks book (for free) from Leanpub.
The data is sourced from the World Resources Institute (http://www.wri.org/chart/world-greenhouse-gas-emissions-2005). Open in full window for full effect.
<!DOCTYPE html>
<meta charset="utf-8">
<title>SANKEY Experiment</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;
}
.link:hover {
stroke-opacity: .5;
}
</style>
<body>
<p id="chart">
<script src="//d3js.org/d3.v3.js"></script>
<script src="sankey.js"></script>
<script>
var units = "Units";
var margin = {top: 10, right: 10, bottom: 10, left: 10},
width = 1400 - margin.left - margin.right,
height = 740 - margin.top - margin.bottom;
var formatNumber = d3.format(",.0f"), // zero decimal places
format = function(d) { return formatNumber(d) + " " + units; },
color = d3.scale.category20();
// append the svg canvas to the page
var svg = d3.select("#chart").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(36)
.nodePadding(10)
.size([width, height]);
var path = sankey.link();
// load the data with d3.csv instead of d3.json
//for another much simpler example uncomment the below
// d3.csv("d3noob_example.csv", function(error, data) {
d3.csv("d3noob_energy.csv", function(error, data) {
//set up graph in same style as original example but empty
graph = {"nodes" : [], "links" : []};
data.forEach(function (d) {
graph.nodes.push({ "name": d.source });
graph.nodes.push({ "name": d.target });
graph.links.push({ "source": d.source, "target": d.target, "value": +d.value });
});
//thanks Mike Bostock https://groups.google.com/d/msg/d3-js/pl297cFtIQk/Eso4q_eBu1IJ
//this handy little function returns only the distinct / unique nodes
graph.nodes = d3.keys(d3.nest()
.key(function (d) { return d.name; })
.map(graph.nodes));
//it appears d3 with force layout wants a numeric source and target
//so loop through each link replacing the text with its index from node
graph.links.forEach(function (d, i) {
graph.links[i].source = graph.nodes.indexOf(graph.links[i].source);
graph.links[i].target = graph.nodes.indexOf(graph.links[i].target);
});
//now loop through each nodes to make nodes an array of objects rather than an array of strings
graph.nodes.forEach(function (d, i) {
graph.nodes[i] = { "name": d };
});
sankey
.nodes(graph.nodes)
.links(graph.links)
.layout(32);
// add in the links
var link = svg.append("g").selectAll(".link")
.data(graph.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; });
// 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(graph.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));
// add the rectangles for the nodes
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); });
// 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 = Math.max(0, Math.min(width - d.dx, d3.event.x))
) + "," + (
d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))
) + ")");
sankey.relayout();
link.attr("d", path);
}
});
</script>
</body>
</html>source,target,value
Agricultural Energy Use,Carbon Dioxide,1.4
Agriculture,Agriculture Soils,5.2
Agriculture,Livestock and Manure,5.4
Agriculture,Other Agriculture,1.7
Agriculture,Rice Cultivation,1.5
Agriculture Soils,Nitrous Oxide,5.2
Air,Carbon Dioxide,1.7
Aluminium Non-Ferrous Metals,Carbon Dioxide,1
Aluminium Non-Ferrous Metals,HFCs - PFCs,0.2
Cement,Carbon Dioxide,5
Chemicals,Carbon Dioxide,3.4
Chemicals,HFCs - PFCs,0.5
Chemicals,Nitrous Oxide,0.2
Coal Mining,Carbon Dioxide,0.1
Coal Mining,Methane,1.2
Commercial Buildings,Carbon Dioxide,6.3
Deforestation,Carbon Dioxide,10.9
Electricity and heat,Agricultural Energy Use,0.4
Electricity and heat,Aluminium Non-Ferrous Metals,0.4
Electricity and heat,Cement,0.3
Electricity and heat,Chemicals,1.3
Electricity and heat,Commercial Buildings,5
Electricity and heat,Food and Tobacco,0.5
Electricity and heat,Iron and Steel,1
Electricity and heat,Machinery,1
Electricity and heat,Oil and Gas Processing,0.4
Electricity and heat,Other Industry,2.7
Electricity and heat,Pulp - Paper and Printing,0.6
Electricity and heat,Residential Buildings,5.2
Electricity and heat,T and D Losses,2.2
Electricity and heat,Unallocated Fuel Combustion,2
Energy,Electricity and heat,24.9
Energy,Fugitive Emissions,4
Energy,Industry,14.7
Energy,Other Fuel Combustion,8.6
Energy,Transportation,14.3
Food and Tobacco,Carbon Dioxide,1
Fugitive Emissions,Coal Mining,1.3
Fugitive Emissions,Oil and Gas Processing,3.2
Harvest \/ Management,Carbon Dioxide,1.3
Industrial Processes,Aluminium Non-Ferrous Metals,0.4
Industrial Processes,Cement,2.8
Industrial Processes,Chemicals,1.4
Industrial Processes,Other Industry,0.5
Industry,Aluminium Non-Ferrous Metals,0.4
Industry,Cement,1.9
Industry,Chemicals,1.4
Industry,Food and Tobacco,0.5
Industry,Iron and Steel,3
Industry,Oil and Gas Processing,2.8
Industry,Other Industry,3.8
Industry,Pulp - Paper and Printing,0.5
Iron and Steel,Carbon Dioxide,4
Land Use Change,Deforestation,10.9
Land Use Change,Harvest \/ Management,1.3
Landfills,Methane,1.7
Livestock and Manure,Methane,5.1
Livestock and Manure,Nitrous Oxide,0.3
Machinery,Carbon Dioxide,1
Oil and Gas Processing,Carbon Dioxide,3.6
Oil and Gas Processing,Methane,2.8
Other Agriculture,Methane,1.4
Other Agriculture,Nitrous Oxide,0.3
Other Fuel Combustion,Agricultural Energy Use,1
Other Fuel Combustion,Commercial Buildings,1.3
Other Fuel Combustion,Residential Buildings,5
Other Fuel Combustion,Unallocated Fuel Combustion,1.8
Other Industry,Carbon Dioxide,6.6
Other Industry,HFCs - PFCs,0.4
Pulp - Paper and Printing,Carbon Dioxide,1.1
Rail - Ship and Other Transport,Carbon Dioxide,2.5
Residential Buildings,Carbon Dioxide,10.2
Rice Cultivation,Methane,1.5
Road,Carbon Dioxide,10.5
T and D Losses,Carbon Dioxide,2.2
Transportation,Air,1.7
Transportation,Rail - Ship and Other Transport,2.5
Transportation,Road,10.5
Unallocated Fuel Combustion,Carbon Dioxide,3
Unallocated Fuel Combustion,Methane,0.4
Unallocated Fuel Combustion,Nitrous Oxide,0.4
Waste,Landfills,1.7
Waste,Waste water - Other Waste,1.5
Waste water - Other Waste,Methane,1.2
Waste water - Other Waste,Nitrous Oxide,0.3
source,target,value
Barry,Elvis,2
Frodo,Elvis,2
Frodo,Sarah,2
Barry,Alice,2
Elvis,Sarah,2
Elvis,Alice,2
Sarah,Alice,4//from Mike Bostock
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) {
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;
};