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Interrupted Mollweide Oceans

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In “Selecting a Map Projection” (Sep. 2012), the National Geographic presented an ocean-centric aspect of an interrupted Mollweide projection.

See also Interrupted Homolosine Oceans.

index.html

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<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/d3-geo-projection.v2.min.js"></script>
<script src="https://d3js.org/topojson.v1.min.js"></script>
<script>

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var lobes = [
  [
    [[-180, 0], [-130, 90], [-90, 5]],
    [[-90, 5], [-30, 90], [60, 5]],
    [[60, 5], [120, 90], [180, 0]]
  ],
  [
    [[-180, 0], [-120, -90], [-60, -5]],
    [[-60, -5], [20, -90], [90, -5]],
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  ]
];
var projection = d3.geoInterrupt(d3.geoMollweideRaw, lobes)
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    .fitExtent([[10,10], [width-30, height-10]], {type: "Sphere"});

  
var graticule = d3.geoGraticule();

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svg.append("use")
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svg.append("path")
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    .attr("class", "graticule")
    .attr("clip-path", "url(#clip)")
    .attr("d", path);

var marker = svg.append("path")
  .attr("fill", "red")

svg.on('mousemove', function() {
  var mouse = d3.mouse(this);
  marker.attr("d", path({type:"Point", coordinates: projection.invert(mouse)}));
});


d3.json("https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/world-50m.json", function(error, world) {
  if (error) throw error;

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      .datum(topojson.feature(world, world.objects.land))
      .attr("class", "land")
      .attr("clip-path", "url(#clip)")
      .attr("d", path);

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      .datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
      .attr("class", "boundary")
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      .attr("d", path);
});

</script>