sfg2gpc: Convert polygonal '"sfg"' to '"gpc.poly"'

In WastlM/polyCub: Cubature over Polygonal Domains

Convert polygonal "sfg" to "gpc.poly"

Description

Package polyCub implements a converter from class "(MULTI)POLYGON" of package sf to "gpc.poly" of package gpclib such that polyCub.exact.Gauss can be used with simple feature polygons.

Usage

sfg2gpc(object)

Arguments

object

a "POLYGON" or "MULTIPOLYGON" "sfg" object.

Value

The converted polygon of class "gpc.poly". If package gpclib is not available, sfg2gpc will just return the pts slot of the "gpc.poly" (no formal class) with a warning.

Note

Package gpclib is required for the formal class definition of a "gpc.poly".

Author(s)

Sebastian Meyer

See Also

xylist

Examples

## use example polygons from
example(plotpolyf, ask = FALSE)
letterR  # a simple "xylist"

letterR.sfg <- sf::st_polygon(lapply(letterR, function(xy)
    rbind(cbind(xy$x, xy$y), c(xy$x[1], xy$y[1]))))
letterR.sfg
stopifnot(identical(letterR, xylist(letterR.sfg)))

## convert sf "POLYGON" to a "gpc.poly"
letterR.gpc_from_sfg <- sfg2gpc(letterR.sfg)
letterR.gpc_from_sfg

WastlM/polyCub documentation built on July 18, 2024, 1:38 p.m.