d3.geoDistance(a, b) Returns the great-arc distance in

projection.clipAngle([angle]) If angle is specified, sets the projection’s clipping circle radius to the specified

graticule.extent([extent]) If extent is specified, sets the major and minor extents of this graticule. If extent

projection.translate([translate]) If translate is specified, sets the projection’s translation offset to the

circle(arguments…) Returns a new GeoJSON geometry object of type “Polygon” approximating a circle on the surface of a sphere

circle.center([center]) If center is specified, sets the circle center to the specified point [longitude

projection.fitSize(size, object) A convenience method for

circle.precision([angle]) If precision is specified, sets the circle precision to the specified angle in degrees

d3.geoCentroid(feature) Returns the spherical centroid of the specified GeoJSON feature. See also

graticule.step([step]) If step is specified, sets the major and minor step for this graticule. If step