Yes, agreed... I realized that after having formulated the question and posted it!!!!
Tim Keitt a écrit : > 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] > <mailto:[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 <mailto: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]]
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