terra (version 1.9-25)

tessellate: Create a tesselation

Description

Create a tessellation of polygons with no gaps or overlaps that cover constant area. The polygons can be hexagons or rectangles. For lon/lat coordinates it is also possible to use (Goldberg) polyhedrons with 12 pentagonal cells and 10*(n^2-1) hexagonal cells, of approximately equal size. Hexagons have constant area, but varying shape with lon/lat coordinates.

Usage

# S4 method for ANY
tessellate(x, size, n, type="hexagon", flat_top=FALSE, align="fit", geo=NULL)

Value

SpatVector of polygons

See Also

as.polygons

Examples

# planar hexagons (exact tiling, equal Cartesian area)
e <- ext(0, 100, 0, 100)
h <- tessellate(e, size=10)
plot(h)

# flat-top hexagons over a raster's extent
r <- rast(nrows=10, ncols=10, xmin=0, xmax=100, ymin=0, ymax=80, crs="local")
h2 <- tessellate(r, size=15, flat_top=TRUE)
plot(h2)

# rectangles
r1 <- tessellate(r, size=15, type="rect", geo=FALSE)
r2 <- tessellate(ext(r), size=1000000, type="rect", geo=TRUE)
r3 <- tessellate(ext(r), size=1000000, type="rect", align="equal", geo=TRUE)
r4 <- tessellate(ext(r), size=1000000, type="rect", align="cube", geo=TRUE)

# global lon/lat equal-area hexagon tessellation
g <- tessellate(size=1000000, geo=TRUE)
g

# global polyhedron, frequency 10 -> 12 pentagons + 990 hexagons
g1 <- tessellate(n=10, type="polyhedron")
g1$size <- expanse(g1)
plot(g1, "type", col=c("tomato", "skyblue"))
plot(g1, "size")


# the truncated icosahedron ("football"): n=1, 12 pentagons + 0 hexagons
g2 <- tessellate(n=1, type="polyhedron")

# specify cell size in meters instead of frequency
g3 <- tessellate(size=1000000, type="polyhedron")