I have more than 50 raster files (ASCII format) that I need to crop. I already exported the mask from ArcMap in ASCII format as well and loaded it into R. How can I make it work for all rasters in a row and export them with the same name as before (of course in a different folder to not overwrite)?
I know there is a crop function in the raster package, but I never used it so far. I only stacked them for further habitat analysis.
My Code so far:
#### Use only part of area
files2 <- list.files(path="D:/",full.names=TRUE, pattern = "\\.asc$")
files2
# Create a RasterLayer from first file
mask_raster <- raster(files2[1])
# Crop. But how??
crop(x = , y=mask_raster)
writeRaster(...)`
I did not find an easy solution to crop multiple rasters by a raster, but by a shape file. So I just went back to ArcMap and converted the raster into a shapefile. Then in R, crop and mask were the crucial steps. See code below (modified from Mauricio Zambrano-Bigiarini's code). Hope this helps.
# Reading the shapefile (mask to crop later)
Maskshp <- readOGR("mask.shp")
# Getting the spatial extent of the shapefile
e <- extent(Maskshp)
# for loop with (in this case) 60 runs
for (i in 1:60) {
# Reading the raster to crop
files <- list.files(path="...your path",full.names=TRUE, pattern = "\\.asc$")
Env_raster <- raster(files[i])
# Save the filename
filename <- (paste(basename(files[i]), sep=""))
# Crop the raster
Env_raster.crop <- crop(Env_raster, e, snap="out")
# Dummy raster with a spatial extension equal to the cropped raster,
# but full of NA values
crop <- setValues(Env_raster.crop, NA)
# Rasterize the catchment boundaries, with NA outside the catchment boundaries
Maskshp.r <- rasterize(Maskshp, crop)
# Putting NA values in all the raster cells outside the shapefile boundaries
Maskshp.masked <- mask(x=Env_raster.crop, mask=Maskshp.r)
plot(Maskshp.masked)
#Export file to working directory with original name as new name
writeRaster(Maskshp.masked, filename)
}