R: Force a POLYGON or MULTIPOLYGON to be clockwise

st_force_polygon_cw {lwgeom} | R Documentation

## Force a POLYGON or MULTIPOLYGON to be clockwise

### Description

Check if a POLYGON or MULTIPOLYGON is clockwise, and if not make it so. According to the 'Right-hand-rule', outer rings should be clockwise, and inner holes should be counter-clockwise

### Usage

    st_force_polygon_cw(x)

### Arguments

`x` | object with polygon geometries

### Value

object of the same class as `x`

### Examples

    library(sf)
    polys <- st_sf(cw = c(FALSE, TRUE),
                   st_as_sfc(c('POLYGON ((0 0, 1 0, 1 1, 0 0))',
                               'POLYGON ((1 1, 2 2, 2 1, 1 1))')))

    st_force_polygon_cw(polys)
    st_force_polygon_cw(st_geometry(polys))
    st_force_polygon_cw(st_geometry(polys)[[1]])

[Package lwgeom version 0.2-7 Index]