index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Adding Labels to the Map</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js"></script>
</head>
<body>
<style>
body {
margin: 0;
}
svg {
background-color: #A7DBD8;
}
.sphere {
fill: #A7DBD8;
stroke: #79A09E;
}
.land {
fill: #E0E4CC;
stroke: #ACAF9F;
stroke-width: 1;
}
.graticule {
fill: none;
stroke: #79A09E;
stroke-width: 1;
stroke-dasharray: 1,2;
}
.label {
font-family: 'Helvetica Neue', Helvetica, sans-serif;
font-size: 11px;
fill: #777;
}
</style>
<div id="map-container"></div>
<script>
var width = 960,
height = 480;
var state = {
x: 0,
y: 0,
scale: height / 2
};
var div = d3.select('#map-container'),
svg = div.append('svg');
svg.attr('width', width).attr('height', height);
var projection = d3.geo.equirectangular()
.translate([width / 2, height / 2]);
var pathGenerator = d3.geo.path()
.projection(projection);
var graticule = d3.geo.graticule();
d3.json('countries.geojson', function(err, data) {
if (err) { throw err; }
var grp = svg.selectAll('g.container').data([data]);
grp.enter().append('g').classed('container', true);
grp.exit().remove();
var sphere = grp.selectAll('path.sphere').data([{type: 'Sphere'}]);
sphere.enter().append('path').classed('sphere', true);
sphere.attr('d', pathGenerator);
sphere.exit().remove();
var lines = grp.selectAll('path.graticule').data([graticule()]);
lines.enter().append('path').classed('graticule', true);
lines.attr('d', pathGenerator);
lines.exit().remove();
var land = grp.selectAll('path.land').data([data]);
land.enter().append('path').classed('land', true);
land.attr('d', pathGenerator);
land.exit().remove();
var labelData = data.features.filter(function(d) {
return d.properties.labelrank < 4;
});
var labels = grp.selectAll('text.label').data(labelData);
labels.enter().append('text')
.classed('label', true);
labels
.attr('x', function(d) { return projection(d3.geo.centroid(d))[0]; })
.attr('y', function(d) { return projection(d3.geo.centroid(d))[1]; })
.attr('text-anchor', function(d, i) {
var idx = Math.round(3 * Math.random());
return ['start', 'middle', 'end'][idx];
})
.text(function(d) { return d.properties.admin; });
labels.exit().remove();
});
</script>
</body>
</html>
Makefile
URL = http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/50m/cultural/ne_50m_admin_0_countries.zip
ne_50m_admin_0_countries.zip:
curl -LO $(URL)
ne_50m_admin_0_countries.shp: ne_50m_admin_0_countries.zip
unzip ne_50m_admin_0_countries.zip
touch ne_50m_admin_0_countries.shp
countries.geojson: ne_50m_admin_0_countries.shp
ogr2ogr -f GeoJSON countries.geojson ne_50m_admin_0_countries.shp
countries.topojson: countries.geojson
topojson -p -o countries.topojson countries.geojson
clean:
rm ne_50m_admin_0_countries*