Public
Edited
Aug 1, 2023
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15 stars
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Directed chord diagram
chart = {
const width = 1080;
const height = width;
const innerRadius = Math.min(width, height) * 0.5 - 20;
const outerRadius = innerRadius + 6;
// Compute a dense matrix from the weighted links in data.
const names = Array.from(d3.union(data.flatMap(d => [d.source, d.target])));
const index = new Map(names.map((name, i) => [name, i]));
const matrix = Array.from(index, () => new Array(names.length).fill(0));
for (const {source, target, value} of data) matrix[index.get(source)][index.get(target)] += value;
const chord = d3.chordDirected()
.padAngle(12 / innerRadius)
.sortSubgroups(d3.descending)
.sortChords(d3.descending);
const arc = d3.arc()
.innerRadius(innerRadius)
.outerRadius(outerRadius);
const ribbon = d3.ribbonArrow()
.radius(innerRadius - 0.5)
.padAngle(1 / innerRadius);
const colors = d3.schemeCategory10;
const formatValue = x => `${x.toFixed(0)}B`;
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [-width / 2, -height / 2, width, height])
.attr("style", "width: 100%; height: auto; font: 10px sans-serif;");
const chords = chord(matrix);
const textId = DOM.uid("text");
svg.append("path")
.attr("id", textId.id)
.attr("fill", "none")
.attr("d", d3.arc()({outerRadius, startAngle: 0, endAngle: 2 * Math.PI}));
svg.append("g")
.attr("fill-opacity", 0.75)
.selectAll()
.data(chords)
.join("path")
.attr("d", ribbon)
.attr("fill", d => colors[d.target.index])
.style("mix-blend-mode", "multiply")
.append("title")
.text(d => `${names[d.source.index]} owes ${names[d.target.index]} ${formatValue(d.source.value)}`);
const g = svg.append("g")
.selectAll()
.data(chords.groups)
.join("g");
g.append("path")
.attr("d", arc)
.attr("fill", d => colors[d.index])
.attr("stroke", "#fff");
g.append("text")
.attr("dy", -3)
.append("textPath")
.attr("xlink:href", textId.href)
.attr("startOffset", d => d.startAngle * outerRadius)
.text(d => names[d.index]);
g.append("title")
.text(d => `${names[d.index]}
owes ${formatValue(d3.sum(matrix[d.index]))}
is owed ${formatValue(d3.sum(matrix, row => row[d.index]))}`);
return svg.node();
}
data = FileAttachment("debt.csv").csv({typed: true})
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
