d3.geoRectangularPolyconic() d3.geoRectangularPolyconicRaw(phi0) The rectangular (War Office) polyconic projection.

d3.geoQuincuncial(project) Defines a new quincuncial projection for the specified raw projection function project. The default rotation is [-90°, -90°, 45°] and the default clip angle is 180° - ε.

d3.geoQuantize(object, digits) Quantizes the specified GeoJSON object, modifying it in-place, rounding x and y coordinates according to number.toFixed. Typically this is done after projecting. See also geoproject --precision and geo2svg --precision.

d3.geoProjectionMutator(factory) Constructs a new projection from the specified raw projection factory and returns a mutate function to call whenever the raw projection changes. The factory must return a raw projection. The returned mutate function returns the wrapped projection. For example, a conic projection typically has two configurable parallels. A suitable factory function, such as d3.geoConicEqualAreaRaw, would have the form: // y0 and y1 represent two parallels function conicFactory(

d3.geoProjection(project) Constructs a new projection from the specified raw projection, project. The project function takes the longitude and latitude of a given point in radians, often referred to as lambda (λ) and phi (φ), and returns a two-element array [x, y] representing its unit projection. The project function does not need to scale or translate the point, as these are applied automatically by projection.scale, projection.translate, and projection.center. Likewise, the project functio

geoproject [options…] projection [file] Projects the GeoJSON object in the specified input file using the specified projection, outputting a new GeoJSON object with projected coordinates. For example, to project standard WGS 84 input using d3.geoAlbersUsa: geoproject 'd3.geoAlbersUsa()' us.json \ > us-albers.json For geometry that crosses the antimeridian or surrounds a pole, you will want to pass input through geostitch first: geostitch world.json \ | geoproject 'd3.geoMercator()' \

d3.geoPolyhedralWaterman() Steve Waterman’s butterfly projection.

d3.geoPolyhedralCollignon() The Collignon butterfly projection.

d3.geoPolyhedralButterfly() The gnomonic butterfly projection.

d3.geoPolyhedral(root, face[, angle]) Defines a new polyhedral projection. The root is a spanning tree of polygon face nodes; each node is assigned a node.transform matrix. The face function returns the appropriate node for a given lambda and phi in radians. The specified rotation angle is applied to the polyhedron; if an angle is not specified, it defaults to -π / 6 (for butterflies).