Build regular polygons

Construct one or more regular polygons (equal sides and angles) as sfg/sfc POLYGON geometry. sfshape_ngon() builds a single polygon at a given center; sfshape_ngons() builds n polygons, automatically arranged in a compact, non-overlapping grid. Useful for building varied, non-hand-typed node geometries; see the geometry vignette for examples, and sfshape_stars for the star-shaped equivalent.

Usage

sfshape_ngon(cx = 0, cy = 0, sides = 5, radius = 1)

sfshape_ngons(n, sides = c(3, 5, 7), radius = 0.3, spacing = NULL)

Arguments

cx, cy

Numeric. Coordinates of the polygon's center. (sfshape_ngon() only.)

sides

Integer. Number of sides; must be 3 or more. For sfshape_ngons(), may be a vector, recycled across the n polygons to vary shape per polygon.

radius

Numeric. Circumradius – distance from the center to each vertex. For sfshape_ngons(), may be a vector, recycled across the n polygons.

n

Integer. Number of polygons to build. (sfshape_ngons() only.)

spacing

Numeric. Distance between polygon centers in the auto-generated grid. Defaults to max(radius) * 2.5, which guarantees no overlap. (sfshape_ngons() only.)

Value

sfshape_ngon() returns a single sfg object of type POLYGON. sfshape_ngons() returns an sfc of n such polygons.

See also

sfshape_stars

Examples

pentagon <- sfshape_ngon(0, 0, sides = 5, radius = 1)
hexagon  <- sfshape_ngon(2, 0, sides = 6, radius = 1)
plot(sf::st_sfc(pentagon, hexagon))


many <- sfshape_ngons(7, sides = c(3, 5, 8), radius = 0.4)
plot(many)