0

I have 20 rasters stored in a list called allrasters. They have different extents (see below). I want to stack them so first I use lapply to crop all list items to the raster with the smallest extent - the 10th list item.

library(raster)
rastlist <- list.files(path = "C:/Users/bhauptman/Box/Ch2/R/data/tif_shp", pattern='.tif$', all.files=TRUE, full.names=T)
allrasters <- lapply(rastlist, raster)
crop_allrasters <-lapply(allrasters, FUN = crop, allrasters[[10]])

It runs but when I check to see if they all now have the same extent, no:

compareRaster(crop_allrasters)
>Error in compareRaster(crop_allrasters) : different extent

Here are the original extents of the 20 rasters:

    > extent(allrasters[[1]])
class      : Extent 
xmin       : -223287.4 
xmax       : 122512.6 
ymin       : -340387.9 
ymax       : 298012.1 
> extent(allrasters[[2]])
class      : Extent 
xmin       : -459600.8 
xmax       : 335249.2 
ymin       : -503894.5 
ymax       : 449855.5 
> extent(allrasters[[3]])
class      : Extent 
xmin       : -459600.8 
xmax       : 335249.2 
ymin       : -503894.5 
ymax       : 449855.5 
> extent(allrasters[[4]])
class      : Extent 
xmin       : -260723.4 
xmax       : 150713.8 
ymin       : -350863.2 
ymax       : 305266.8 
> extent(allrasters[[5]])
class      : Extent 
xmin       : -260740.3 
xmax       : 150709.6 
ymin       : -350843.9 
ymax       : 305286.1 
> extent(allrasters[[6]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[7]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[8]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[9]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[10]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[11]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[12]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[13]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[14]])
class      : Extent 
xmin       : -223300 
xmax       : 129000 
ymin       : -344600 
ymax       : 298550 
> extent(allrasters[[15]])
class      : Extent 
xmin       : -421253.8 
xmax       : 293346.2 
ymin       : -463338.6 
ymax       : 411561.4 
> extent(allrasters[[16]])
class      : Extent 
xmin       : -421253.8 
xmax       : 293346.2 
ymin       : -463338.6 
ymax       : 411561.4 
> extent(allrasters[[17]])
class      : Extent 
xmin       : -260776 
xmax       : 150724 
ymin       : -350868.1 
ymax       : 305331.9 
> extent(allrasters[[18]])
class      : Extent 
xmin       : -260776 
xmax       : 150724 
ymin       : -350868.1 
ymax       : 305331.9 
> extent(allrasters[[19]])
class      : Extent 
xmin       : -260776 
xmax       : 150724 
ymin       : -350868.1 
ymax       : 305331.9 
> extent(allrasters[[20]])
class      : Extent 
xmin       : -260776 
xmax       : 150724 
ymin       : -350868.1 
ymax       : 305331.9
BHope
  • 135
  • 9

1 Answers1

1

In principle that should work, illustrated here with some example data and with terra instead of raster

library(terra)
f <- system.file("ex/elev.tif", package="terra")
x = list(r, r, crop(r, c(5,6,49,50)))
y = lapply(x, crop, y=x[[3]])

sapply(x, \(i) as.vector(ext(i))) |> t()
#         xmin     xmax     ymin     ymax
#[1,] 5.741667 6.533333 49.44167 50.19167
#[2,] 5.741667 6.533333 49.44167 50.19167
#[3,] 5.741667 6.000000 49.44167 50.00000

sapply(y, \(i) as.vector(ext(i))) |> t()
#         xmin xmax     ymin ymax
#[1,] 5.741667    6 49.44167   50
#[2,] 5.741667    6 49.44167   50
#[3,] 5.741667    6 49.44167   50

It seems that this does not work for some of the input rasters in your case. You could try to use crop directly on those rasters to find out why.

Robert Hijmans
  • 40,301
  • 4
  • 55
  • 63
  • Thank you for the suggestion I tried to directly copy raster with another and still did not work. I then used resample_allrasters10 <- lapply(allrasters, FUN=resample, allrasters[[10]]) and now the extends match. I had already checked the CRS before messing with extents and they were the same so not sure why resample worked? – BHope Apr 01 '22 at 02:34
  • that suggest that the spatial resolution and/or origins were also different. – Robert Hijmans Apr 01 '22 at 16:23
  • Correct on checking crs was ok but origin was not. – BHope Apr 01 '22 at 19:44