[GRASS-user] Rotate raster map?

[Markus Neteler]

On Tue, Sep 24, 2019 at 4:28 PM Rich Shepard <rshepard at appl-ecosys.com> wrote:
>
> Looking through the r.* in the core and extensions lists I don't see a
> module that rotates a raster map.

See
https://grass.osgeo.org/grass78/manuals/r.in.gdal.html#notes
"Georeferencing If the dataset has affine georeferencing information,
this will be used to set the north, south, east and west edges.
Rotational coefficients will be ignored, resulting in incorrect
positioning for rotated datasets."

https://grass.osgeo.org/grass78/manuals/r.in.gdal.html#error-messages
"... the image must be first externally rotated, applying the rotation
info stored in the metadata field of the raster image file. For
example, the gdalwarp software can be used to transform the map to
North-up (note, there are several gdalwarp parameters to select the
resampling algorithm):

gdalwarp rotated.tif northup.tif
"

Markus