Public
Edited
Aug 1, 2023
256 forks
Importers
39 stars
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Sankey diagram
Line chart, percent changeStacked area chartBubble chartArea chartHorizontal bar chartRadial tidy treeCircle packingIcicleStreamgraphTidy treeCluster treeSunburstHorizon chartBox plotScatterplotDifference chartBand chartBar chart transitionsTreemapLine chart, multiple seriesScatterplot matrixBrushable scatterplot matrixPlayfair's Wheat and Wages
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chart = {
// Specify the dimensions of the chart.
const width = 928;
const height = 600;
const format = d3.format(",.0f");

// Create a SVG container.
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.attr("style", "max-width: 100%; height: auto; font: 10px sans-serif;");

// Constructs and configures a Sankey generator.
const sankey = d3.sankey()
.nodeId(d => d.name)
.nodeAlign(d3[nodeAlign]) // d3.sankeyLeft, etc.
.nodeWidth(15)
.nodePadding(10)
.extent([[1, 5], [width - 1, height - 5]]);

// Applies it to the data. We make a copy of the nodes and links objects
// so as to avoid mutating the original.
const {nodes, links} = sankey({
nodes: data.nodes.map(d => Object.assign({}, d)),
links: data.links.map(d => Object.assign({}, d))
});

// Defines a color scale.
const color = d3.scaleOrdinal(d3.schemeCategory10);

// Creates the rects that represent the nodes.
const rect = svg.append("g")
.attr("stroke", "#000")
.selectAll()
.data(nodes)
.join("rect")
.attr("x", d => d.x0)
.attr("y", d => d.y0)
.attr("height", d => d.y1 - d.y0)
.attr("width", d => d.x1 - d.x0)
.attr("fill", d => color(d.category));

// Adds a title on the nodes.
rect.append("title")
.text(d => `${d.name}\n${format(d.value)} TWh`);

// Creates the paths that represent the links.
const link = svg.append("g")
.attr("fill", "none")
.attr("stroke-opacity", 0.5)
.selectAll()
.data(links)
.join("g")
.style("mix-blend-mode", "multiply");

// Creates a gradient, if necessary, for the source-target color option.
if (linkColor === "source-target") {
const gradient = link.append("linearGradient")
.attr("id", d => (d.uid = DOM.uid("link")).id)
.attr("gradientUnits", "userSpaceOnUse")
.attr("x1", d => d.source.x1)
.attr("x2", d => d.target.x0);
gradient.append("stop")
.attr("offset", "0%")
.attr("stop-color", d => color(d.source.category));
gradient.append("stop")
.attr("offset", "100%")
.attr("stop-color", d => color(d.target.category));
}

link.append("path")
.attr("d", d3.sankeyLinkHorizontal())
.attr("stroke", linkColor === "source-target" ? (d) => d.uid
: linkColor === "source" ? (d) => color(d.source.category)
: linkColor === "target" ? (d) => color(d.target.category)
: linkColor)
.attr("stroke-width", d => Math.max(1, d.width));

link.append("title")
.text(d => `${d.source.name} → ${d.target.name}\n${format(d.value)} TWh`);

// Adds labels on the nodes.
svg.append("g")
.selectAll()
.data(nodes)
.join("text")
.attr("x", d => d.x0 < width / 2 ? d.x1 + 6 : d.x0 - 6)
.attr("y", d => (d.y1 + d.y0) / 2)
.attr("dy", "0.35em")
.attr("text-anchor", d => d.x0 < width / 2 ? "start" : "end")
.text(d => d.name);

return svg.node();
}
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data = {
const links = await FileAttachment("energy.csv").csv({typed: true});
const nodes = Array.from(new Set(links.flatMap(l => [l.source, l.target])), name => ({name, category: name.replace(/ .*/, "")}));
return {nodes, links};
}
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// [d3-sankey](https://github.com/d3/d3-sankey) is not part of the D3 bundle
d3 = require("d3@7", "d3-sankey@0.12")
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