[GRASS-dev] MASK seems to be ignored

[Michael Barton]

On Feb 5, 2008, at 9:48 AM, Patton, Eric wrote:

>> The way I understand it is that a MASK will affect all subsequent
>> *read* operations for processing a raster map. That is...
>>
>> r.mapcalc 'newmap=oldmap'
>>
>> ...will just produce an unaltered copy of oldmap without a MASK; with
>> a MASK it will produce a copy of oldmap only in the area of MASK.
>>
>> MASK will not affect the display. It is for map processing.
>
>> Michael
>
> It seems that the current mask does affect the display, though.  
> I've placed three
> screenshots on ftp://gsca.nrcan.gc.ca/outgoing/Patton. The 'Before'  
> image is the
> full extent of my input raster; I zoomed into a small region in the  
> display,
> set the region to that of the display extent, and created a mask  
> using r.mapcalc !isnull(MAP).
> I then zoomed back to my original display extent, set the region  
> back to that of
> the display, and redrew the display, the output of which is the  
> 'After' image.
>
> The display is being clipped by the current mask.


Eric,

You are right. I stand corrected (or sit in this case).

Michael


>
> ~ Eric.
>
>
>