Create a gist now

Instantly share code, notes, and snippets.

@mbostock /.block
Last active Feb 9, 2016

Merging States
license: gpl-3.0
.DS_Store
build
node_modules

Using topojson.merge to merge states & provinces into a single feature from the Natural Earth 1:10,000,000 Admin 1 dataset.

The orange arc is an artifact of the merge that might either be a bug in the merge algorithm or in the dataset (or both).

<!DOCTYPE html>
<meta charset="utf-8">
<style>
.graticule {
fill: none;
stroke: #777;
stroke-opacity: .5;
stroke-width: .5px;
pointer-events: none;
}
.land {
fill: #222;
stroke: orange;
}
.border {
fill: none;
stroke: #fff;
stroke-width: .5px;
}
</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 = 960;
var projection = d3.geo.mercator()
.scale(width / 2 / Math.PI)
.translate([width / 2, height / 2])
.precision(.1);
var path = d3.geo.path()
.projection(projection);
var graticule = d3.geo.graticule();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
svg.append("path")
.datum(graticule)
.attr("class", "graticule")
.attr("d", path);
d3.json("world.json", function(error, world) {
if (error) throw error;
svg.insert("path", ".graticule")
.datum(topojson.merge(world, world.objects.states.geometries))
.attr("class", "land")
.attr("d", path);
svg.insert("path", ".graticule")
.datum(topojson.mesh(world, world.objects.states, function(a, b) { return a !== b; }))
.attr("class", "border")
.attr("d", path);
});
d3.select(self.frameElement).style("height", height + "px");
</script>
GENERATED_FILES = \
world.json
all: $(GENERATED_FILES)
clean:
rm -rf -- $(GENERATED_FILES)
.PHONY: all clean
build/ne_10m_%.zip:
mkdir -p $(dir $@)
curl -o $@ "http://www.nacis.org/naturalearth/10m/cultural/ne_10m_$*.zip"
build/ne_%_admin_1_states_provinces.shp: build/ne_%_admin_1_states_provinces_shp.zip
mkdir -p $(dir $@)
unzip -od $(dir $@) $<
for file in $(dir $@)/ne_$*_admin_1_states_provinces_shp.*; do mv $$file $(dir $@)/ne_$*_admin_1_states_provinces"$${file#*_shp}"; done
touch $@
world.json: build/ne_10m_admin_1_states_provinces.shp
node_modules/.bin/topojson \
-o $@ \
-q 1e5 \
--simplify-proportion .1 \
-- states=$<
{
"name": "anonymous",
"version": "0.0.1",
"private": true,
"dependencies": {
"topojson": "1"
}
}
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment