Koen, That's a bug. You can, indeed, avoid it by using expand=TRUE (perhaps followed by crop to remove the expanded area). This will be fixed in next version of raster. Robert
On Mon, Jul 1, 2013 at 5:49 AM, Koen Hufkens <[email protected]> wrote: > Hi everyone, > > I've been experiencing errors using the aggregate() raster function on > large files. It only seems to happen when using the expand=FALSE option. > > The warning I get reads: > > Warning message: > In .rasterFromRasterFile(grdfile, band = band, objecttype) : > size of values file does not match the number of cells (given the data > type) > > And most of the time the bottom rows of the resulting aggregated image > contains values that read -3.4e+38 (which to me is rather arbitrairy). > > I'm running: > R version 3.0.1 (2013-05-16) -- "Good Sport" > Platform: x86_64-pc-linux-gnu (64-bit) > raster 2.1-37 > > Any clues on how to solve this would be appreciated. The error also seems > to be limited to large files > 5000 x 5000 pixels or so. > > Best, > Koen > > > -------------- > a copy of the example code: > > >> # aggregate error on large files >> >> # read image >> img <- mean(brick('/home/khufkens/virton.tif')) >> # show image info >> img > class : RasterLayer > dimensions : 10342, 10342, 106956964 (nrow, ncol, ncell) > resolution : 0.7464698, 0.7464698 (x, y) > extent : 611736.7, 619456.7, 6379237, 6386957 (xmin, xmax, ymin, ymax) > coord. ref. : +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 > +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs > data source : > /tmp/R_raster_tmp/khufkens/raster_tmp_2013-07-01_142516_99728.grd > names : layer > values : 0, 213.3333 (min, max) > >> # set window size >> windowsize <- 81 > >> zones <- aggregate(img,fact=windowsize,fun=mean,expand=TRUE,na.rm=TRUE) >> # show results info >> zones > class : RasterLayer > dimensions : 128, 128, 16384 (nrow, ncol, ncell) > resolution : 60.46405, 60.46405 (x, y) > extent : 611736.7, 619476.1, 6379218, 6386957 (xmin, xmax, ymin, ymax) > coord. ref. : +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 > +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs > data source : > /tmp/R_raster_tmp/khufkens/raster_tmp_2013-07-01_142555_110676.grd > names : layer > values : 24.63222, 138.7439 (min, max) > >> zones <- aggregate(img,fact=windowsize,fun=mean,expand=FALSE,na.rm=TRUE) >> # BAM! > Warning message: > In .rasterFromRasterFile(grdfile, band = band, objecttype) : > size of values file does not match the number of cells (given the data > type) > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
