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Last active March 25, 2023 13:23
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Force-Directed Tree
license: gpl-3.0
redirect: https://observablehq.com/@d3/force-directed-tree
{
"nodes": [
{"name": "d3"},
{"name": "d3.svg"},
{"name": "d3.svg.area"},
{"name": "d3.svg.line"},
{"name": "d3.scale"},
{"name": "d3.scale.linear"},
{"name": "d3.scale.ordinal"}
],
"links": [
{"source": 0, "target": 1},
{"source": 1, "target": 2},
{"source": 1, "target": 3},
{"source": 0, "target": 4},
{"source": 4, "target": 5},
{"source": 4, "target": 6}
]
}
<!DOCTYPE html>
<meta charset="utf-8">
<style>
circle {
stroke-width: 1.5px;
}
line {
stroke: #999;
stroke-width: 1.5px;
}
</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>
var width = 960,
height = 500,
radius = 6;
var fill = d3.scale.category20();
var force = d3.layout.force()
.charge(-120)
.linkDistance(30)
.size([width, height]);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
d3.json("graph.json", function(error, json) {
if (error) throw error;
var link = svg.selectAll("line")
.data(json.links)
.enter().append("line");
var node = svg.selectAll("circle")
.data(json.nodes)
.enter().append("circle")
.attr("r", radius - .75)
.style("fill", function(d) { return fill(d.group); })
.style("stroke", function(d) { return d3.rgb(fill(d.group)).darker(); })
.call(force.drag);
force
.nodes(json.nodes)
.links(json.links)
.on("tick", tick)
.start();
function tick(e) {
var k = 6 * e.alpha;
// Push sources up and targets down to form a weak tree.
link
.each(function(d) { d.source.y -= k, d.target.y += k; })
.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return d.target.x; })
.attr("y2", function(d) { return d.target.y; });
node
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
}
});
</script>
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