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@jonsadka /.block
Last active Feb 13, 2017

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TopoJSON Map of Los Angeles
license: mit
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/topojson.v2.min.js"></script>
<style>
body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
path {
stroke: gray;
fill: none;
}
</style>
</head>
<body>
<script>
const width = 960;
const height = 960;
const svg = d3.select('body').append('svg')
.attr('height', width)
.attr('width', height);
d3.queue()
.defer(d3.json, 'la.json')
.await(render)
function render(error, la) {
if (error) return console.warn(error);
// Create a unit projection.
const laProjection = d3.geoAlbers()
.scale(1)
.translate([0, 0]);
// Create a path generator
const path = d3.geoPath()
.projection(laProjection);
// Compute the bounds of a feature of interest,
// then derive scale & translate.
const laBounds = path.bounds(la);
const laScale = 0.95 / Math.max(
(laBounds[1][0] - laBounds[0][0]) / width,
(laBounds[1][1] - laBounds[0][1]) / height
);
const laTranslate = [
(width - laScale * (laBounds[1][0] + laBounds[0][0])) / 2,
(height - laScale * (laBounds[1][1] + laBounds[0][1])) / 2
];
// Update the projection to use computed scale & translate.
console.log(laBounds);
console.log(laScale, laTranslate)
laProjection.scale(laScale)
.translate(laTranslate);
svg.append('path')
.datum(la)
.attr('d', path);
}
</script>
</body>
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