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Last active July 1, 2023 06:53
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Merging States
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.state {
fill: #ccc;
}
.state-boundary {
fill: none;
stroke: #fff;
}
.state.selected {
fill: orange;
stroke: #000;
}
</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>
var width = 960,
height = 600;
var projection = d3.geo.albersUsa()
.scale(1280)
.translate([width / 2, height / 2]);
var path = d3.geo.path()
.projection(projection);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var selected = d3.set([
9, 10, 12, 13, 17, 18, 19, 21, 23, 24,
25, 26, 29, 31, 33, 34, 36, 37, 39, 42,
44, 45, 47, 50, 51, 54, 55
]);
d3.json("/mbostock/raw/4090846/us.json", function(error, us) {
if (error) throw error;
svg.append("path")
.datum(topojson.feature(us, us.objects.states))
.attr("class", "state")
.attr("d", path);
svg.append("path")
.datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
.attr("class", "state-boundary")
.attr("d", path);
svg.append("path")
.datum(topojson.merge(us, us.objects.states.geometries.filter(function(d) { return selected.has(d.id); })))
.attr("class", "state selected")
.attr("d", path);
});
d3.select(self.frameElement).style("height", height + "px");
</script>
@DDDgfx
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DDDgfx commented Oct 27, 2015

How can I find the centroid of a merged shape?

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