[GRASS-user] mask in PERMANENT affect on other mapsets during reprojection

Jarekj jarekj at amu.edu.pl
Mon Jun 30 00:43:32 EDT 2008

So as I understand the problem will heppen when I have mask in mapset in 
source which is named as my target mapset in target location: ussually 
it will concern PERMANENT?

Thanks for information

Glynn Clements pisze:
> [CC to grass-dev]
> Jarekj wrote:
>> The situation is as follows:
>> In location GRS mapset PERMANET I have MASK (with projection of 2180 
>> based on GRS elipsoid)
>> in second mapset let say jarekjaI have map which is to be reprojected to 
>> other location (WGS). In that mapset no MASK is present.
>> In location WGS mapset PERMANENT  I reporject map from location GRS and 
>> I have only fragment allowed by MASK from GRS PERMANENT It is intended 
>> or some bug?
> The MASK file has to exist in the current mapset in the current
> location.
> However: r.proj keeps switching the current location between the two
> locations. It switches to the source location when opening and reading
> the input map, and switches back to the target location when opening
> and writing the output map.
> Where it looks for the mask is determined by which is the current one
> at the point that it looks. This point isn't well defined; it normally
> happens as a side effect of some other function.
> AFAICT, it uses the source location when looking for the mask. 
> However, it doesn't change the mapset; i.e. it uses the current mapset
> (not the mapset= value), which may not even exist in the source
> location.
> This is quite clearly a bug; it should switch mapsets when it switches
> locations. At present the code only uses the mapset= value when
> opening the input map, overlooking the fact that it is also used
> internally, e.g. when looking for the mask.

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