Calculate area of raster cells
On Wed, 28 Apr 2010, Paul Hiemstra wrote:
Tim Erbrecht wrote:
Dear all, having data in a SpatialGridDataFrame with geographic coordinates, is there a simple method to calculate the spatial area for each cell? I wasn't able to find anything in the list archives ... Thanks and best regards Tim ------------------------------------------------------------------------
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with the meuse dataset: library(sp) data(meuse.grid) gridded(meuse.grid) = ~x+y fullgrid(meuse.grid) = TRUE bla = gridparameters(meuse.grid) area = bla$cellsize[1] * bla$cellsize[2] area
These are projected, not geographical coordinates, unfortunately. The case for calculating areas on an ellipsoid is much harder, I'm afraid. Roger
cheers, Paul
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no