chart = {
const root = d3.hierarchy(data);
root.x0 = dy / 2;
root.y0 = 0;
root.descendants().forEach((d, i) => {
d.id = i;
d._children = d.children;
if (d.depth && d.data.name.length !== 7) d.children = null;
});
const svg = d3
.create("svg")
.attr("viewBox", [-margin.left, -margin.top, width, dx])
.style("font", "10px sans-serif")
.style("user-select", "none");
const gLink = svg
.append("g")
.attr("fill", "none")
.attr("stroke", "#555")
.attr("stroke-opacity", 0.4)
.attr("stroke-width", 1.5);
const gNode = svg
.append("g")
.attr("cursor", "pointer")
.attr("pointer-events", "all");
function update(event, source) {
const duration = event && event.altKey ? 2500 : 250;
const nodes = root.descendants().reverse();
const links = root.links();
// Compute the new tree layout.
tree(root);
let left = root;
let right = root;
root.eachBefore((node) => {
if (node.x < left.x) left = node;
if (node.x > right.x) right = node;
});
const height = right.x - left.x + margin.top + margin.bottom;
const transition = svg
.transition()
.duration(duration)
.attr("viewBox", [-margin.left, left.x - margin.top, width, height])
.tween(
"resize",
window.ResizeObserver ? null : () => () => svg.dispatch("toggle")
);
// Update the nodes…
const node = gNode.selectAll("g").data(nodes, (d) => d.id);
// Enter any new nodes at the parent's previous position.
const nodeEnter = node
.enter()
.append("g")
.attr("transform", (d) => `translate(${source.y0},${source.x0})`)
.attr("fill-opacity", 0)
.attr("stroke-opacity", 0)
.on("click", (event, d) => {
d.children = d.children ? null : d._children;
update(event, d);
});
nodeEnter
.append("circle")
.attr("r", 2.5)
.attr("fill", (d) => (d._children ? "#555" : "#999"))
.attr("stroke-width", 10);
nodeEnter
.append("text")
.attr("dy", "0.31em")
.attr("x", (d) => (d._children ? -6 : 6))
.attr("text-anchor", (d) => (d._children ? "end" : "start"))
.text((d) => d.data.name)
.clone(true)
.lower()
.attr("stroke-linejoin", "round")
.attr("stroke-width", 3)
.attr("stroke", "white");
// Transition nodes to their new position.
const nodeUpdate = node
.merge(nodeEnter)
.transition(transition)
.attr("transform", (d) => `translate(${d.y},${d.x})`)
.attr("fill-opacity", 1)
.attr("stroke-opacity", 1);
// Transition exiting nodes to the parent's new position.
const nodeExit = node
.exit()
.transition(transition)
.remove()
.attr("transform", (d) => `translate(${source.y},${source.x})`)
.attr("fill-opacity", 0)
.attr("stroke-opacity", 0);
// Update the links…
const link = gLink.selectAll("path").data(links, (d) => d.target.id);
// Enter any new links at the parent's previous position.
const linkEnter = link
.enter()
.append("path")
.attr("d", (d) => {
const o = { x: source.x0, y: source.y0 };
return diagonal({ source: o, target: o });
});
// Transition links to their new position.
link.merge(linkEnter).transition(transition).attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link
.exit()
.transition(transition)
.remove()
.attr("d", (d) => {
const o = { x: source.x, y: source.y };
return diagonal({ source: o, target: o });
});
// Stash the old positions for transition.
root.eachBefore((d) => {
d.x0 = d.x;
d.y0 = d.y;
});
}
update(event, root);
return svg.node();
}
diagonal = d3.linkHorizontal().x(d => d.y).y(d => d.x)
tree = d3.tree().nodeSize([dx, dy])
data = FileAttachment("flare-2.json").json()
dx = 10
dy = width / 6
margin = ({top: 10, right: 120, bottom: 10, left: 40})
d3 = require("d3@7")
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.
