Tissot's Indicatrix rendered with D3.
NB:- see Jason's comment about these not being "true" Tissot indicatrices.
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<meta charset="utf-8">
<style>
body {
margin: 0;
}
.background {
fill: #bee8ff;
}
.foreground {
fill: none;
stroke: #ccc;
stroke-width: 1.5px;
}
.graticule {
fill: none;
stroke: #aaa;
stroke-width: .5px;
}
.land {
fill: #b7db6e;
stroke: #4f6521;
}
.boundary {
fill: none;
stroke: #7b9545;
}
.tissot {
fill: rgba(255,0,0,0.5);
stroke: none;
}
</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>
var radians = Math.PI / 180.0;
var width = window.innerWidth,
height = window.innerHeight;
var projection = d3.geo.orthographic()
.scale(Math.min(width,height)*0.45)
.translate([width / 2 - .5, height / 2 - .5])
.rotate([-30,-30])
.clipAngle(90 + 1e-6);
var path = d3.geo.path()
.projection(projection);
var graticule = d3.geo.graticule().step([30,30]);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
svg.append("path")
.datum(graticule.outline)
.attr("class", "background")
.attr("d", path);
svg.selectAll(".graticule")
.data(graticule.lines)
.enter().append("path")
.attr("class", "graticule")
.attr("d", path);
svg.append("path")
.datum(graticule.outline)
.attr("class", "foreground")
.attr("d", path);
d3.json("readme-boundaries.json", function(error, collection) {
svg.insert("path", ".graticule")
.datum(collection)
.attr("class", "boundary")
.attr("d", path);
});
d3.json("readme-land.json", function(error, collection) {
svg.insert("path", ".graticule,.boundary")
.datum(collection)
.attr("class", "land")
.attr("d", path);
});
var indicatices = d3.merge(d3.range(-180,181,30).map(function(lon) {
return d3.range(-60,61,30).map(function(lat) {
return d3.geo.circle().origin([ lon, lat ]).angle(7.0)();
});
}));
svg.selectAll("path.tissot")
.data(indicatices)
.enter().append("path")
.attr("class", "tissot")
.attr("d", path);
</script>
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js