Write multiple rasters in R

Question

I am trying to write a series of raster files into a new folder (after doing some image processing). However, when using my code, the files are but are not in the folder that I have created for that purpose.

I say they are but they are not because when I run my code and take a look inside the folder that I have created, a file pops-up, disappears, pops-up, disappears and this goes until I hit stop the R console.

Here is my code

Img.Raster <- list()
for (k in 1:length(list.pics)){
  Img.Raster[[k]] <- raster(list.pics[k])
  extent(Img.Raster[[k]])=c(coordinate.one.Image$CenterLeftx[[k]], coordinate.one.Image$CenterRightx[[k]],
                            coordinate.one.Image$CenterBottomy[[k]], coordinate.one.Image$CenterTopy[[k]])
  proj4string(Img.Raster[[k]]) <- "+proj=utm +zone=15 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0"
  writeRaster(Img.Raster[[k]],filename =paste0("/Users/Juan/Desktop/Images_Folder/"
                                                , "Img_",names(list.pics[[k]])), format="GTiff",overwrite=TRUE)
}

list.Image is a variable that contains 1745 images

Those anyone know what could be wrong?

Suggestion by @Jul

for (k in 1:length(list.pics)){
  Img.Raster[[k]] <- raster(list.pics[k])
  extent(Img.Raster[[k]])=c(coordinate.one.Image$CenterLeftx[[k]], coordinate.one.Image$CenterRightx[[k]],
                            coordinate.one.Image$CenterBottomy[[k]], coordinate.one.Image$CenterTopy[[k]])
  proj4string(Img.Raster[[k]]) <- "+proj=utm +zone=15 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0"
  writeRaster(Img.Raster[[k]],filename =paste0("/Users/Juan/Desktop/Images_Folder/"
                                                , "Img_",stringr::str_pad(string = k,width = 4,side = "left",pad=0),
                                               format="GTiff",overwrite=T)
}

Answer 1

Try changing the names(list.pics[[k]]) to names(list.pics[k]).

I think you want the names of each element in the list (presumably 1745 unique names in total), not the names within each raster element, which I'd guess are the same for every element. The appearing/disappearing behaviour is probably because every file is being given the same filename and you've set overwrite=TRUE. It will probably throw a 'file already exists' error without the overwrite argument.

EDIT after comment thread: Please ensure you are passing unique filenames to the writeRaster call. Swapping names(list.pics[k]) for stringr::str_pad(string = k,width = 4,side = "left",pad=0) should work.

Suggestion

for (k in 1:length(list.pics)){
  Img.Raster[[k]] <- raster(list.pics[k])
  extent(Img.Raster[[k]])=c(coordinate.one.Image$CenterLeftx[[k]], coordinate.one.Image$CenterRightx[[k]],
                            coordinate.one.Image$CenterBottomy[[k]], coordinate.one.Image$CenterTopy[[k]])
  proj4string(Img.Raster[[k]]) <- "+proj=utm +zone=15 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0"
  writeRaster(Img.Raster[[k]],filename =paste0("/Users/Juan/Desktop/Images_Folder/", "Img_",stringr::str_pad(string = k,width = 4,side = "left",pad=0)),format="GTiff",overwrite=TRUE)
}