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@d3indepth
Last active November 20, 2019 08:05
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d3.geoInterpolate example
license: gpl-3.0
height: 420
border: no
<!DOCTYPE html>
<meta charset="utf-8">
<head>
<title>Geo interpolator</title>
</head>
<style>
body {
font-family: "Helvetica Neue", Helvetica, sans-serif;
font-size: 14px;
color: #333;
}
</style>
<body>
<div id="content">
<canvas width="800" height="400"></canvas>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.2/d3.min.js"></script>
<script>
var geojson = {}
var context = d3.select('#content canvas')
.node()
.getContext('2d');
var projection = d3.geoOrthographic()
.scale(500)
.rotate([30, -45]);
var geoGenerator = d3.geoPath()
.projection(projection)
.pointRadius(4)
.context(context);
var londonLonLat = [0.1278, 51.5074];
var newYorkLonLat = [-74.0059, 40.7128];
var geoInterpolator = d3.geoInterpolate(londonLonLat, newYorkLonLat);
var u = 0;
function update() {
context.clearRect(0, 0, 800, 600);
context.lineWidth = 0.5;
context.strokeStyle = '#333';
context.beginPath();
geoGenerator({type: 'FeatureCollection', features: geojson.features})
context.stroke();
// Graticule
var graticule = d3.geoGraticule();
context.beginPath();
context.strokeStyle = '#ccc';
geoGenerator(graticule());
context.stroke();
// London - New York
context.beginPath();
context.strokeStyle = 'red';
geoGenerator({type: 'Feature', geometry: {type: 'LineString', coordinates: [londonLonLat, newYorkLonLat]}});
context.stroke();
// Point
context.beginPath();
context.fillStyle = 'red';
geoGenerator({type: 'Feature', geometry: {type: 'Point', coordinates: geoInterpolator(u)}});
context.fill();
u += 0.01
if(u > 1) u = 0
}
// REQUEST DATA
d3.json('https://gist.githubusercontent.com/d3indepth/f28e1c3a99ea6d84986f35ac8646fac7/raw/c58cede8dab4673c91a3db702d50f7447b373d98/ne_110m_land.json', function(err, json) {
geojson = json;
window.setInterval(update, 50);
// update(json);
})
</script>
</body>
</html>
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