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@mbostock
Last active Aug 17, 2017
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Great Arc
license: gpl-3.0

A simple example drawing a great arc as a LineString. The projection is rotated to avoid interrupting the arc. See also an earlier example with multiple great arcs.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
.graticule {
fill: none;
stroke: #777;
stroke-width: .5px;
stroke-opacity: .5;
}
.land {
fill: #bbb;
}
.arc {
fill: none;
stroke: red;
stroke-width: 3px;
stroke-linecap: round;
}
.boundary {
fill: none;
stroke: #fff;
stroke-width: .5px;
stroke-linejoin: round;
stroke-linecap: round;
}
</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>
var width = 960,
height = 480;
var projection = d3.geo.equirectangular()
.scale(153)
.rotate([160, 0])
.translate([width / 2, height / 2])
.precision(.1);
var path = d3.geo.path()
.projection(projection);
var graticule = d3.geo.graticule();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
svg.append("path")
.datum(graticule)
.attr("class", "graticule")
.attr("d", path);
svg.append("path")
.datum({type: "LineString", coordinates: [[-77.05, 38.91], [116.35, 39.91]]})
.attr("class", "arc")
.attr("d", path);
d3.json("/mbostock/raw/4090846/world-50m.json", function(error, world) {
if (error) throw error;
svg.insert("path", ".graticule")
.datum(topojson.feature(world, world.objects.land))
.attr("class", "land")
.attr("d", path);
svg.insert("path", ".graticule")
.datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
.attr("class", "boundary")
.attr("d", path);
});
d3.select(self.frameElement).style("height", height + "px");
</script>
@sidsamant
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sidsamant commented Aug 13, 2017

Thanks for the nice example. I am new to d3 and the map projections.

Is there any example to draw an uninterrupted great arc without rotating the equirectangular projection?

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