
force counter-clockwise polygons
forceCCW.RdAssure that the nodes of outer rings of polygons are in counter-clockwise order.
Examples
p <- vect("POLYGON ((2 45, 2 55, 18 55, 18 45, 2 45))")
pcc <- forceCCW(p)
geom(pcc, wkt=TRUE)
#> [1] "POLYGON ((2.0000000000000000 45.0000000000000000, 18.0000000000000000 45.0000000000000000, 18.0000000000000000 55.0000000000000000, 2.0000000000000000 55.0000000000000000, 2.0000000000000000 45.0000000000000000))"