I have just stumbled upon a bit of an issue while using r.proj in
grass6.0. The situation is as follows: I have imported a 10m dem of a
comparatively large scale (zoomed out area) of a 10m dem, and what I
would like to do is import this dem into a location of a smaller region
using r.proj (I have done this successfully in a different scenario),
but it complains that "the input map is outside current region." I
figure that the problem is just as grass reports it, but I am not sure
how to fix it/make it work. The projection converion is from nad83 to
nad27. (On a separate note, is this inverse chronical conversion an
error--is it better to run map projects in the most recent projection
systems?)
I have just stumbled upon a bit of an issue while using r.proj in
grass6.0. The situation is as follows: I have imported a 10m dem of a
comparatively large scale (zoomed out area) of a 10m dem, and what I
would like to do is import this dem into a location of a smaller region
using r.proj (I have done this successfully in a different scenario),
but it complains that "the input map is outside current region."
In all cases I encountered this error message it turned out to be true. Please check (or provide us) your projection info and region settings for both the input map and output location.
Global maps are special. If you are working with global maps you should disable the region/map cropping in r.proj with the -n option, because you have to import and reserve memory for the whole map anyway. But the -n option is not useful if the input map is not global and really is outside your current region.
Maybe you zoomed out from the default region too much so your region edges are now in outer space or otherwise unreasonable for the projection in question? That may give strange results.
Not sure how to cope with r.proj here, but you could:
1 cut the piece od DEM you want with r.mapcalc
2 r.out.gdal to GeoTiff
3 gdalwarp
4 r.in.gdal
A note: as far I was told on this list before by wise folks and as I have confirmed in my experience, reprojecting raster DEM is *not* a good idea for most typical purpose (e.g. you won't be happy with the resulting aspect or slope). Better t.to.vect, v.proj, re-interpolate (say v.surf.rst). Good luck.
Maciek
----- Original Message ----- From: "Michael Kowen" <michael.kowen@case.edu>
To: <grasslist@baylor.edu>
Sent: Monday, June 06, 2005 9:19 PM
Subject: [GRASSLIST:7031] region related issues with r.proj
Hello again,
I have just stumbled upon a bit of an issue while using r.proj in
grass6.0. The situation is as follows: I have imported a 10m dem of a
comparatively large scale (zoomed out area) of a 10m dem, and what I
would like to do is import this dem into a location of a smaller region
using r.proj (I have done this successfully in a different scenario),
but it complains that "the input map is outside current region." I
figure that the problem is just as grass reports it, but I am not sure
how to fix it/make it work. The projection converion is from nad83 to
nad27. (On a separate note, is this inverse chronical conversion an
error--is it better to run map projects in the most recent projection
systems?)
I have just stumbled upon a bit of an issue while using r.proj in
grass6.0. The situation is as follows: I have imported a 10m dem of
a comparatively large scale (zoomed out area) of a 10m dem, and what I
would like to do is import this dem into a location of a smaller
region using r.proj (I have done this successfully in a different
scenario), but it complains that "the input map is outside current
region." I figure that the problem is just as grass reports it,
but I am not sure how to fix it/make it work. The projection
converion is from nad83 to nad27. (On a separate note, is this inverse
chronical conversion an error--is it better to run map projects in the
most recent projection systems?)
Hint for getting the region correct:
Use v.in.region to rectify a box showing where your data will end up,
and then rectify the raster to this fine tuned region.