There may be a problem. mapply(function(a, b, c) exp(a), A, B, C)
alas > exp(A[[1]]) > class : RasterLayer > dimensions : 2, 2, 4 (nrow, ncol, ncell) > resolution : 0.5, 0.5 (x, y) > extent : 0, 1, 0, 1 (xmin, xmax, ymin, ymax) > coord. ref. : NA > data source : in memory > names : layer > values : 2.718282, 54.59815 (min, max) Looks like exp() doesn't work from inside `mapply`. Robert? # I changed c to d, because it's hell to debug `c` D <- mapply(function(a, b, d) { > browser() 1/(1 - exp(-exp(-((a - b)/d)))) > }, A, B, C) Browse[1]> class(a) > [1] "RasterLayer" > attr(,"package") > [1] "raster" > Browse[1]> exp(a) > Error in as.character(sys.call(sys.parent())[[1]]) : > cannot coerce type 'closure' to vector of type 'character' Cheers, Roman On Mon, Feb 11, 2013 at 2:14 PM, Lorenzo Alfieri <alfio...@hotmail.com>wrote: > > Dear list, > I'm trying to apply a function to lists of rasters, but without success. > I'm not sure if it feasible of if I should use a for loop. > Let's say a, b and c are three lists of argument to my function > 1/(1-exp(-exp(-((a - b)/c)))) (2 rasters each) > I'd like this function to be applied to these arguments, so that I get as > result a list D of 2 rasters, where for example > D[[1]] = 1/(1-exp(-exp(-((A[[1]] - B[[1]])/C[[1]])))) and the same for > D[[2]] > > I tryed with this but didn't work: > > library(raster) > > aa<-matrix(c(2,1,3,4),nrow=2,ncol=2) > bb<-matrix(c(5,7,4,6),nrow=2,ncol=2) > cc<-matrix(c(12,13,17,16),nrow=2,ncol=2) > A<-list(raster(aa),raster(t(aa))) > B<-list(raster(bb),raster(t(bb))) > C<-list(raster(cc),raster(t(cc))) > > D<-mapply(function(a,b,c) 1/(1-exp(-exp(-((a - b)/c)))), A,B,C) > > Any suggestions? > > Lorenzo > > > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > -- In God we trust, all others bring data. [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo