You can use the calc function too, based on the same example Roman gave library(raster) set.seed(1) r1 <- raster(matrix(runif(9), ncol = 3)) r2 <- raster(matrix(runif(9), ncol = 3)) r3 <- raster(matrix(runif(9), ncol = 3)) r <- stack(r1, r2, r3)
res1 <- calc(r, fun = max) ## maximum value of all 3 rasters res2 <- calc(r, fun = function(x) which.max(x)) ### number of the layer with maximum value On Sat, Mar 8, 2014 at 2:01 PM, Roman LuÅ¡trik <[email protected]>wrote: > You mean something like this? Basically I just wrapped a function around > extract. > > library(raster) > > r1 <- raster(matrix(runif(9), ncol = 3)) > r2 <- raster(matrix(runif(9), ncol = 3)) > r3 <- raster(matrix(runif(9), ncol = 3)) > r <- stack(r1, r2, r3) > > cellvals <- extract(r, 3) > which(cellvals == max(cellvals)) > > getStats <- function(cell, x, fun) { > getvals <- extract(x, cell) > ind <- which(getvals == fun(getvals)) > getvals[, ind, drop = FALSE] > } > > sapply(1:3, getStats, fun = max, x = r) > > Cheers, > Roman > > > > On Sat, Mar 8, 2014 at 2:21 PM, Maurizio Marchi > <[email protected]>wrote: > > > Hallo everybody. > > Is there a way to see in a rasterstack with the raster package which > layer > > has the higer value for a selected pixel? > > I have a rasterstack with 22 raster layers and I would like to have an > > unique raster with, for each pixel, the maximum value of 22 rasters. > > For example: > > Pixel number 12345 , maximum value is 9876 from layer number XX. > > > > I hope to be clear enough... > > Bests, > > Maurizio > > > > > > -- > > Maurizio Marchi > > ID skype: maurizioxyz > > *Ubuntu 12.04 LTS* > > *"Il bello dell'open-source è che le domande possono essere poste alla > > fonte"* > > *utente linux 552.742* > > > > [[alternative HTML version deleted]] > > > > > > _______________________________________________ > > R-sig-Geo mailing list > > [email protected] > > 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 > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > -- Ahmadou H. DICKO statistician economist (Ingénieur Statisticien Ãconomiste) PhD candidate in Climate change economics Faculty of economics and managment - Cheikh Anta Diop University West African Science Service Center on Climate Change and Adaptated Land Use (WASCAL) Center for Development Research (ZEF) - University of Bonn email : [email protected] twitter : @dickoah github : github/dickoa <https://github.com/dickoa> tel : +221 33 827 55 16 portable: +221 77 123 81 69 [[alternative HTML version deleted]]
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