Import raster stack and return new layer

Question

I am trying to import about 50 .tif files into a stack using the rasters package. Because of the large number of files I don't want to list them all out. I have tried a few methods but have been unsuccessful, including this code:

test<-stack(choose.files(),values=T) Error in .local(x, ...) : Arguments should be Raster* objects or filenames

In addition I want to classify a new raster based on the 50 I import. For example I have a group of polygons with the same extent (could convert to raster) and want to count the number of times a value "1" occurs in each polygon. I figure the "overlay" function would be best for this but am having trouble thinking of how to code the associated function. Any help would be appreciated.

it matters not that it's 50, do a test with just two, list them all out, test that they really are files that can be seen with file.exists() - my bet is your file paths are not right, or the files are raster-readable, demonstrate to yourself that it works with 1 by raster(x) — mdsumner

Robert Hijmans Robert Hijmans · Accepted Answer · 2013-05-11T19:12:18

The easier way with many files should be to use (with some modifications)

f <- list.files(path='???', pattern='.tif$', full.names=TRUE)
s <- stack(f)

But if you want to do it interactively:

f <- choose.files()
s <- stack(f)

The error occurred because you use "values=TRUE" (which is not an argument to stack and gets interpreted as a file name)

Import raster stack and return new layer

1 Answers