[GRASS-dev] MASK seems to be ignored
michael.barton at asu.edu
Tue Feb 5 11:10:51 EST 2008
On Feb 5, 2008, at 8:20 AM, grass-dev-request at lists.osgeo.org wrote:
> Date: Tue, 5 Feb 2008 10:20:02 -0500
> From: "Patton, Eric" <epatton at nrcan.gc.ca>
> Subject: [GRASS-dev] MASK seems to be ignored
> To: <grass-user at lists.osgeo.org>
> Cc: grass-dev at lists.osgeo.org
> <CA803441152AAE40935609509953BAD201075FB6 at s0-ott-x4.nrn.nrcan.gc.ca>
> Content-Type: text/plain; charset="iso-8859-1"
> I'm having problems getting a MASK to actually mask anything.
> $ r.mask in=Diff_Nov2007_Oct2007_1m
> MASK created. All subsequent raster operations
> will be limited to MASK area
> Removing or renaming raster file named MASK will
> restore raster operations to normal
> [Raster MASK present]
> Yet all refreshes of the gis.m map display window do not clip the
> display extents
> based on the new mask(see attached png). In the screenshot, the
> mask is the pink raster,
> and underneath it is another raster in my mapset. Shouldn't the
> underlying raster's display
> be clipped to that of the mask?
> Using r.mapcalc while the mask exists also doesn't seem to obey the
> extents of the mask, i.e.:
> r.mapcalc test = 'Diff_Oct2007_Mar2007_1m'
> This creates the raster 'test' with data extents that match
> Diff_Oct2007_Mar2007_1m, not the mask's
> I'm using svn-trunk compiled from today's source.
> ~ Eric.
The way I understand it is that a MASK will affect all subsequent
*read* operations for processing a raster map. That is...
...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.
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