Just to confirm my understanding of regions and mapsets I'll ask this
final question on the subject. The PERMANENT mapset holds the base data with
maximum regions for each map. The project mapset has a smaller region, so
when I'm working within that mapset on copies of the maps stored in
PERMANENT, all actions are within the smaller region. With raster maps, too,
like the DEM, all calculations are on the visible portion only. So, when I'm
finished, the original bounds for each map in PERMANENT remain unchanged. I
believe that this is correct.
Thanks,
Rich
--
Richard B. Shepard, Ph.D. | Integrity Credibility
Applied Ecosystem Services, Inc. | Innovation
<http://www.appl-ecosys.com> Voice: 503-667-4517 Fax: 503-667-8863
Just to confirm my understanding of regions and mapsets I'll ask this
final question on the subject. The PERMANENT mapset holds the base data with
maximum regions for each map. The project mapset has a smaller region, so
when I'm working within that mapset on copies of the maps stored in
PERMANENT, all actions are within the smaller region. With raster maps, too,
like the DEM, all calculations are on the visible portion only. So, when I'm
finished, the original bounds for each map in PERMANENT remain unchanged. I
believe that this is correct.
Yes. Any new maps will be created with the bounds and resolution
determined by the current region.
And raster commands don't normally modify existing maps. Some vector
commands modify maps in-place, but raster commands (with very few
exceptions, e.g. r.null) don't.
Yes. Any new maps will be created with the bounds and resolution
determined by the current region.
And raster commands don't normally modify existing maps. Some vector
commands modify maps in-place, but raster commands (with very few
exceptions, e.g. r.null) don't.
Thanks for the confirmation, Glynn.
Now I need to search for a mail list to help me figure out why three
points within the project drainage basin are not within those bounds when I
try to add them to the map.
It's a re-projection issue, not directly a GRASS issue, but I've not found
an answer on the proj.4 Web site ... yet. I'll do some reading today to
ensure I correctly ask the questions.
The PERMANENT mapset holds the base data with
maximum regions for each map. The project mapset has a smaller region,
so when I'm working within that mapset on copies of the maps stored in
PERMANENT, all actions are within the smaller region.
While it is correct that each mapset maintains its own region settings/
bounds, for the record these do not necessarily have to lie exactly
within PERMANENT's region/bounds. It is just a handy way to think about
what the default region might be.
Your grass session will not write outside of the currently loaded mapset.
So anything you do in $MAPSET will not have an effect on PERMANENT. Some-
times it just refuses to go on (like g.setproj) other times it works
around it (eg r.colors keeps a colr2/ color table local override for
maps from other mapsets). The exception is i.rectify which exports X,Y
images to new georeferenced maps in other mapsets.
With raster maps, too, like the DEM, all calculations are on the visible
portion only.
right. An extra complication is that a MASK map (if it exists) is filtered
in the same way, but only applies to the reading of existing map data from
the disk.
So, when I'm finished, the original bounds for each map in
PERMANENT remain unchanged.
yup. thus multi-user or multi-session (but-different-mapsets) can share
the common mapset (in this case PERMANENT) while being protected from
clobbering each other unawares.
yup. thus multi-user or multi-session (but-different-mapsets) can share
the common mapset (in this case PERMANENT) while being protected from
clobbering each other unawares.