Dear Robert ! Thank you very much for your quick answer !
I just ran the bits of code you gave me and it worked perfectly ! Have a good day ! Guillaume Le 10-05-17 11:50, Robert J. Hijmans a écrit :
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
