Dear Guillaume, This probably happened because the aggregate function tests if the output raster can be stored in memory. This is a mistake as it should do the test for the input raster (which is, in this case, 16 times larger). I have just fixed that. For now, you can use this (otherwise *not* recommended (or necessary), as it slows things down) option, to force processing the file in chunks :
setOptions(todisk=TRUE) wam<-aggregate(wam, fact=4, fun=mean, expand=FALSE, filename="wam_ag4", progress='tcltk') setOptions(todisk=FALSE) Robert On Mon, May 17, 2010 at 10:15 AM, Guillaume Blanchet <gblanchet.l...@gmail.com> wrote: > Hi ! > > I recently started to use the raster package to play with a file that I > consider fairly big. Since file size is subjective, following is the > summary output R gives of the data I am working with : > > > wam > class : RasterLayer > filename : w001001.adf > nrow : 14143 > ncol : 11733 > ncell : 165939819 > min value : 0 > max value : 36.3769 > projection : +proj=utm +zone=11 +ellps=GRS80 +datum=NAD83 +units=m > +no_defs +towgs84=0,0,0 > xmin : 410133 > xmax : 421866 > ymin : 6287971 > ymax : 6302114 > xres : 1 > yres : 1 > > I would like to aggregate the information of that RasterLayer. I tried > to use the function aggregate() without any real success. Following is > the code line I use to perform that procedure and the error message I get: > > > wam<-aggregate(wam, fact=4, fun=mean, expand=FALSE, filename="wam_ag4") > > Erreur : impossible d'allouer un vecteur de taille 633.0 Mo (A loose > translation would be : "Error: allocating a vector of 633.0 Mb in size > is impossible") > De plus : Messages d'avis : > 1: In .local(x, ...) : > Reached total allocation of 3061Mb: see help(memory.size) > 2: In .local(x, ...) : > Reached total allocation of 3061Mb: see help(memory.size) > 3: In .local(x, ...) : > Reached total allocation of 3061Mb: see help(memory.size) > 4: In .local(x, ...) : > Reached total allocation of 3061Mb: see help(memory.size) > > I understood while reading help files and various posting that the > raster package can handle files larger than the RAM memory of the > computer. The computer I am using has 3Gb of RAM and the file I want to > read is only 633 Mb. I suppose there something I am not doing right. > > Any help would be much appreciated ! > > Thank you in advance ! > > Guillaume Blanchet > > [[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 > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
