rast() - using the win argument when reading in multiple files causes problems

[dfriend21]

I've run into an issue where using the win argument when reading in several raster files into a single SpatRaster causes problems later on. See the example below.

library(terra)
#> terra 1.6.47

# save out 10 rasters, each to different files
ext <- ext(0, 10, 0, 10)
paths <- sapply(1:10, function(i){
  path_i <- tempfile(fileext = ".tif") # also tried .nc, .grd, and .asc - results were the same
  mat <- matrix(i, nrow = 10, ncol = 10)
  writeRaster(rast(mat, extent = ext), path_i)
  return(path_i)
})

# read them in, making use of the 'win' argument to specify a spatial subset
sub_ext <- ext(2, 6, 2, 6)
rasts <- rast(paths, win = sub_ext)

# check the results
rasts[[1]] # correct
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> window      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source      : file8ace2e40c17d.tif 
#> name        : lyr.1 
#> min value   :    >1 
#> max value   :    1<

rasts[[2]] # incorrect - has extent 'sub_ext' but dimensions 10 x 10 (and therefore resolution 0.4 x 0.4), which is incorrect
#> class       : SpatRaster 
#> dimensions  : 10, 10, 1  (nrow, ncol, nlyr)
#> resolution  : 0.4, 0.4  (x, y)
#> window      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source      : file8ace1d5f0d44.tif 
#> name        : lyr.1 
#> min value   :    >2 
#> max value   :    2<

# try performing some operations on the rasters
rasts + 1          # works
#> class       : SpatRaster 
#> dimensions  : 4, 4, 10  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source(s)   : memory
#> names       : lyr.1, lyr.1, lyr.1, lyr.1, lyr.1, lyr.1, ... 
#> min values  :     2,     3,     4,     5,     6,     7, ... 
#> max values  :     2,     3,     4,     5,     6,     7, ...

rasts[[1:10]] + 1  # works
#> class       : SpatRaster 
#> dimensions  : 4, 4, 10  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source(s)   : memory
#> names       : lyr.1, lyr.1, lyr.1, lyr.1, lyr.1, lyr.1, ... 
#> min values  :     2,     3,     4,     5,     6,     7, ... 
#> max values  :     2,     3,     4,     5,     6,     7, ...

rasts[[1]] + 1     # works
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source(s)   : memory
#> name        : lyr.1 
#> min value   :     2 
#> max value   :     2

rasts[[2]] + 1     # doesn't work
#> Warning: /private/var/folders/w5/21t55k2s2l5g7kj4vvvwhshm0000gn/T/Rtmpk9UmqM/file8ace1d5f0d44.tif:
#> Access window out of range in RasterIO(). Requested (2,4) of size 10x10 on
#> raster of 10x10. (GDAL error 5)
#> class       : SpatRaster 
#> dimensions  : 10, 10, 1  (nrow, ncol, nlyr)
#> resolution  : 0.4, 0.4  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84

(rasts + 1)[[2]]   # works
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source(s)   : memory
#> name        : lyr.1 
#> min value   :     3 
#> max value   :     3


#============================================

# now try the same thing, but save the rasters as a single, multi-layered .tif
rasts2 <- rast(lapply(1:10, function(i){
  mat <- matrix(i, nrow = 10, ncol = 10)
  return(rast(mat, extent = ext))
}))
path2 <- tempfile(fileext = ".tif")
writeRaster(rasts2, path2)

rasts2a <- rast(path2, win = sub_ext)
rasts2a[[1]]      # correct
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> window      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source      : file8ace26cf9f01.tif 
#> name        : lyr.1 
#> min value   :    >1 
#> max value   :    1<

rasts2a[[2]]      # correct
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> window      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source      : file8ace26cf9f01.tif 
#> name        : lyr.1 
#> min value   :    >2 
#> max value   :    2<

rasts2a[[2]] + 1  # correct
#> class       : SpatRaster 
#> dimensions  : 4, 4, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 2, 6, 2, 6  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 
#> source(s)   : memory
#> name        : lyr.1 
#> min value   :     3 
#> max value   :     3

# this time everything works

^{Created on 2023-01-04 with reprex v2.0.2}

Session info

─ Session info ───────────────────────────────────────────────────────
 setting  value
 version  R version 4.2.2 (2022-10-31)
 os       macOS Monterey 12.4
 system   aarch64, darwin20
 ui       RStudio
 language (EN)
 collate  en_US.UTF-8
 ctype    en_US.UTF-8
 tz       America/Chicago
 date     2023-01-04
 rstudio  2022.12.0+353 Elsbeth Geranium (desktop)
 pandoc   NA

─ Packages ───────────────────────────────────────────────────────────
 package     * version date (UTC) lib source
 bench         1.1.2   2021-11-30 [1] CRAN (R 4.2.0)
 cli           3.4.1   2022-09-23 [1] CRAN (R 4.2.0)
 codetools     0.2-18  2020-11-04 [1] CRAN (R 4.2.0)
 Rcpp          1.0.9   2022-07-08 [1] CRAN (R 4.2.0)
 rlang         1.0.6   2022-09-24 [1] CRAN (R 4.2.0)
 rstudioapi    0.14    2022-08-22 [1] CRAN (R 4.2.0)
 sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.2.0)
 terra       * 1.6-47  2022-12-02 [1] CRAN (R 4.2.0)

 [1] /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/library

──────────────────────────────────────────────────────────────────────

[rhijmans]

Thank you very much. I think this has now been fixed. I get

dim(x[[1]])
#[1] 4 4 1
dim(x[[2]])
#[1] 4 4 1
res(x[[1]])
#[1] 1 1
res(x[[2]])
[1] 1 1