Reverse the coordinate order of geometries

Reverses the order of the coordinates in every line and ring, keeping the geometry type of the input. ga_reverse() leaves the order of the parts of a multi part geometry unchanged.

Usage

ga_reverse(geometry)

Arguments

geometry

a GeoArrow geometry array

Value

a GeoArrow array of the same geometry type as geometry

Details

ga_reverse() returns points and multipoints, which have no order to reverse, as they are. It flips a polygon's winding; use ga_orient() to set a winding direction instead. It keeps a null geometry null.

See also

Other winding: ga_is_ccw(), ga_orient(), ga_winding_order()

Examples

g <- geoarrow::as_geoarrow_array(sf::st_sfc(
  sf::st_linestring(rbind(c(0, 0), c(1, 1), c(2, 0)))
))

sf::st_as_sfc(geoarrow::as_geoarrow_vctr(ga_reverse(g)))
#> Geometry set for 1 feature 
#> Geometry type: LINESTRING
#> Dimension:     XY
#> Bounding box:  xmin: 0 ymin: 0 xmax: 2 ymax: 1
#> CRS:           NA
#> LINESTRING (2 0, 1 1, 0 0)