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Zoom/Pan Map Example

Demonstrates using d3.behavior.zoom with a geographic projection. Based on an example by Iain Dillingham.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
path {
fill: #E5F5F9;
stroke: #2CA25F;
stroke-width: 0.5;
}
#axes {
stroke: #BDBDBD;
stroke-width: 0.5;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var width = 960,
height = 500,
projection = d3.geo.mercator(),
path = d3.geo.path().projection(projection);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.call(d3.behavior.zoom()
.translate(projection.translate())
.scale(projection.scale())
.on("zoom", redraw));
var axes = svg.append("g").attr("id", "axes"),
xAxis = axes.append("line").attr("y2", height),
yAxis = axes.append("line").attr("x2", width);
d3.json("uk.json", function(error, json) {
svg.selectAll("path")
.data(json.features)
.enter().append("path");
redraw();
});
function redraw() {
if (d3.event) {
projection
.translate(d3.event.translate)
.scale(d3.event.scale);
}
svg.selectAll("path").attr("d", path);
var t = projection.translate();
xAxis.attr("x1", t[0]).attr("x2", t[0]);
yAxis.attr("y1", t[1]).attr("y2", t[1]);
}
</script>
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