polygauss(xy, nw_MN, alpha = NULL, rotation = FALSE, engine = "C")"x" and "y" containing the
polygon vertices in anticlockwise order (otherwise the result of the
cubature will have a negative sign) with first vertex not repeated at the
end (like owin.object$bdrgauss.quad): list(s_M, w_M, s_N, w_N).NULL (default),
the midpoint of the x-range of each polygon is chosen if no rotation
is performed, and otherwise the $xFALSE) or a list of points
"P" and "Q" describing the preferred direction. If
TRUE, the polygon is rotated according to the vertices "P" and
"Q", which are farengine = "R".
The new C-implementation i