Most basic example to center and scale your map with d3.geoBounds(), d3.geoCentroid() and d3.geoDistance().
Created
October 7, 2017 23:07
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Center and Scale your map
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<!DOCTYPE html> | |
<html> | |
<head> | |
<meta charset="utf-8"> | |
<title></title> | |
<script src="//d3js.org/d3.v4.js" charset="utf-8"></script> | |
<script src="//d3js.org/topojson.v1.js"></script> | |
<style> | |
path { | |
stroke-linejoin: round; | |
} | |
.city { | |
fill: rgb(240, 240, 240); | |
stroke: rgb(0, 0, 0); | |
stroke-width: .2; | |
} | |
svg { | |
background-color: #D0E4E7 | |
} | |
.land { | |
fill: rgb(245, 245, 245); | |
} | |
.coast { | |
fill: none; | |
stroke: #76aeb6; | |
stroke-width: 1.5; | |
} | |
</style> | |
</head> | |
<body> | |
<svg width="960" height="500"></svg> | |
<script> | |
d3.queue() | |
.defer(d3.json, 'map.json') | |
.await(function(error, map) { | |
if(error) throw error; | |
var svg = d3.select("svg"), | |
width = +svg.attr("width"), | |
height = +svg.attr("height"); | |
var topology = topojson.feature(map, map.objects.coruna), | |
coast = topojson.feature(map, map.objects.border) | |
var projection = d3.geoMercator() | |
.translate([width / 2, height / 2]); | |
var path = d3.geoPath() | |
.projection(projection) | |
var bounds = d3.geoBounds(topology), | |
center = d3.geoCentroid(topology); | |
// Compute the angular distance between bound corners | |
var distance = d3.geoDistance(bounds[0], bounds[1]), | |
scale = height / distance / Math.sqrt(2); | |
// Update the projection scale and centroid | |
projection.scale(scale).center(center); | |
svg.append("path") | |
.datum(coast) | |
.attr("class", "land") | |
.attr("d", path); | |
svg.append("path") | |
.datum(topology) | |
.attr("class", "city") | |
.attr("d", path); | |
svg.append("path") | |
.datum(coast) | |
.attr("class", "coast") | |
.attr("d", path); | |
}); | |
</script> | |
</body> | |
</html> |
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#!/usr/bin/env bash | |
topojson \ | |
shp/border.shp shp/coruna.shp \ | |
-q 8000 \ | |
-o map.json \ |
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