Dear list, I think I've found a bug with the stackApply() function of the raster package. The bug was already pointed out at : http://r-sig-geo.2731867.n2.nabble.com/raster-stackApply-problems-td7589291.html
It says that it was fixed, however I think it wasn't 100% fixed. I've experienced the same problem with a raster the isn't in memory. Here an example. (I'm sorry you have to download files, I've couldn't manage to reproduce the problem with R-made rasters) ################ ## download these four rasters: https://www.dropbox.com/sh/aoxou1qiqxdiskk/AAAMHeDio6FW6eLDqjMshP2Ka?dl=0 library(raster) sta <- stack("G:\\ layer_1.tif","G:\\ layer_2.tif","G:\\ layer_3.tif","G:\\ layer_4.tif") indices <- c(1,2,2,3) stackApply(sta, indices, fun=sum) indices <- c(3,2,2,1) stackApply(sta, indices, fun=sum) ## If you compare the max-min, you'll see it's not the same between the two calls of stackApply(). ## However, the way the function is described in the help, only the names should be different, not the max-min ## Interestingly, this problem doesn't happen if we crop the file small enough the stack become in memory e <- extent(-515000,-460000,635420,708890) sta.crop <- crop(sta,e) indices <- c(1,2,2,3) stackApply(sta.crop, indices, fun=sum) ### This one works fine! indices <- c(3,2,2,1) stackApply(sta.crop, indices, fun=sum) ## This time is the same (and good) results between the two calls! ############## BTW, I'm using R 3.3.2 64bits and the latest raster package version from CRAN. Is it really a bug or I'm doing something wrong? Thanks for your help, Bastien Ferland-Raymond Division des orientations et des projets spéciaux Direction des inventaires forestiers Ministère des Forêts, de la Faune et des Parcs _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo