I have a raster in working directory:
When I read this using terra package, it reads fine
r1 <- terra::rast(my_rast)
r1
class : SpatRaster
dimensions : 6000, 6000, 8 (nrow, ncol, nlyr)
resolution : 0.0008333333, 0.0008333333 (x, y)
extent : 59.99958, 64.99958, 24.99958, 29.99958 (xmin, xmax, ymin, ymax)
coord. ref. : lon/lat WGS 84 (EPSG:4326)
source : n25e060.tif
names : n25e060_1, n25e060_2, n25e060_3, n25e060_4, n25e060_5, n25e060_6, ...
But If I read the same raster using the raster package, I get the following warning:
r2 <- raster::raster(my_rast)
Warning message:
In .rasterFromGDAL(x, band = band, objecttype, ...) :
data seems flipped. Consider using: flip(x, direction='y')
class : RasterLayer
band : 1 (of 8 bands)
dimensions : 6000, 6000, 3.6e+07 (nrow, ncol, ncell)
resolution : 0.0008333333, 0.0008333333 (x, y)
extent : 59.99958, 64.99958, 25.00042, 30.00042 (xmin, xmax, ymin, ymax)
crs : +proj=longlat +datum=WGS84 +no_defs
source : n25e060.tif
names : n25e060
values : 0, 255 (min, max)
Why is this happening?
That suggests that either {terra} can directly use "flipped" raster data, whereas that {raster} cannot or that {terra} does not notice that the data are flipped. I believe the former to be true, but, while this would be easy for you to verify, I do not have the file so I cannot be 100% sure.