/d3-geo-projection

Extended geographic projections for D3.js.

Primary LanguageJavaScriptOtherNOASSERTION

Extended Geographic Projections

airy
 aitoff
 albers *
 albersUsa *
armadillo
 august
 azimuthalEqualArea *
 azimuthalEquidistant *
baker
 berghaus
 boggs
 bonne
bromley
 chamberlin
 collignon
 conicEqualArea *
conicConformal *
 conicEquidistant *
 craig
 craster
cylindricalEqualArea
 cylindricalStereographic
 eckert1
 eckert2
eckert3
 eckert4
 eckert5
 eckert6
eisenlohr
 equirectangular *
 fahey
 gilbert
ginzburg4
 ginzburg5
 ginzburg6
 ginzburg8
ginzburg9
 gnomonic *
 gringorten
 guyou
hammer
 hammerRetroazimuthal
 healpix
 hill
homolosine
 kavrayskiy7
 lagrange
 larrivee
laskowski
 littrow
 loximuthal
 mercator *
miller
 modifiedStereographic
 mollweide
 mtFlatPolarParabolic
mtFlatPolarQuartic
 mtFlatPolarSinusoidal
 naturalEarth
 nellHammer
orthographic *
 peirceQuincuncial
 polyconic
 polyhedron.butterfly
polyhedron.waterman
 rectangularPolyconic
 robinson
 satellite
sinuMollweide
 sinusoidal
 stereographic *
 times
twoPointAzimuthal
 twoPointEquidistant
 transverseMercator *
 vanDerGrinten
vanDerGrinten2
 vanDerGrinten3
 vanDerGrinten4
 wagner4
wagner6
 wagner7
 wiechel
 winkel3

Projections:

This plugin also provides d3.geo.interrupt, which can be used to create arbitrary interrupted projections from a given raw projection. For example, see Philbrick’s interrupted Sinu-Mollweide.

This plugin requires D3 3.0 or greater. To use the official hosted version, include the projection plugin after including D3:

<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
<script src="http://d3js.org/d3.geo.projection.v0.min.js" charset="utf-8"></script>

Alternatively, you can clone this repo, download the zipball, or right-click d3.geo.projection.v0.min.js and save.

To use this plugin within a Node.js context, you can npm install d3 d3-geo-projection and then say:

var d3 = require("d3");

require("d3-geo-projection")(d3);

Subsequently, d3.geo will contain all the extended projections.

Defining a New Projection

First define your raw projection function:

function cosinusoidal(λ, φ) {
  return [λ * Math.sin(φ), φ];
}

cosinusoidal.invert = function(x, y) {
  return [x / Math.sin(y), y];
};

Then create a constructor using d3.geo.projection:

d3.geo.cosinusoidal = function() {
  return d3.geo.projection(cosinusoidal);
};

You can optionally expose the raw projection to facilitate composite projections:

(d3.geo.cosinusoidal = function() {
  return d3.geo.projection(cosinusoidal);
}).raw = cosinusoidal;