D3

Conic projections ​

Conic projections project the sphere onto a cone, and then unroll the cone onto the plane. Conic projections have two standard parallels.

conic.parallels(parallels) ​

Source · The two standard parallels that define the map layout in conic projections.

geoConicConformal() ​

Source · The conic conformal projection. The parallels default to [30°, 30°] resulting in flat top.

geoConicEqualArea() ​

Source · The Albers’ equal-area conic projection.

geoConicEquidistant() ​

Source · The conic equidistant projection.

geoAlbers() ​

Source · The Albers’ equal area-conic projection. This is a U.S.-centric configuration of geoConicEqualArea.

geoAlbersUsa() ​

Source · This is a U.S.-centric composite projection of three geoConicEqualArea projections: geoAlbers is used for the lower forty-eight states, and separate conic equal-area projections are used for Alaska and Hawaii. The scale for Alaska is diminished: it is projected at 0.35× its true relative area. See Albers USA with Territories for an extension to all US territories, and d3-composite-projections for more examples.

The constituent projections have fixed clip, center and rotation, and thus this projection does not support projection.center, projection.rotate, projection.clipAngle, or projection.clipExtent.