On 09/17/2010 09:47 AM, Arnald Marcer wrote: > Dear listers, > > Can anybody help me with this ? > > How can I mask a 1km UTM grid raster with a list of coordinates > which represent the center of 10km UTM grid squares ? Ultimately > I want the 1km grid raster with only the pixels that fall inside > the 10km UTM grid squares.
convert the first to SpatialPointsDataFrame, and create a SpatialPixels object from the second, then use overlay() to get the indexes of the points that lie within the 10km grid cells. > > Also, how can I build a SpatialPolygonsDataFrame representing 10km > UTM grid squares from a list of coordinates which represent their grid > center. first create a SpatialPixelsDataFrame, say sx, then use as(sx, "SpatialPolygonsDataFrame") > > I will appreciate if you can give me some hints on how to do this. > > Arnald Marcer > CREAF > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of Münster Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebe...@wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
