Do you mean the flat-plane area or the area projected onto the surface of the ellipsoid? In either case, the computation is likely non-trivial. It makes much more sense to project to UTM and do the calculation there.
THK On 5/31/06, Patrick Giraudoux <[EMAIL PROTECTED]> wrote: > > Dear Listers, > > The function areapl() of the package splancs computes polygon areas in > the coordinate units. This means in square meters when using UTM or > Lambert projections but in "square degrees" when using longlat degrees. > > Does anybody knows a R function (or an algorithm) to compute the area > directly (without projecting or projecting internally), eg in square > meters, of a polygon whose node coordinates are given in decimal degrees? > > Thanks for any hint, > > Patrick > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > -- Timothy H. Keitt http://www.keittlab.org/ [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
