I've just spent an hour fighting with setting the region in GRASS 7.
Finally I discovered that the display region and computational region
are now independent. Is there a way to have the computational region
automatically set to the display region, or do we now have to explicitly
link them each time one or the other changes? If there's no way to link
them automatically, is there a way to 'set computational region extent
from display' from the command line?
* Tyler Smith <tyler@plantarum.ca> [2015-04-13 16:43:05 -0400]:
Hi,
I've just spent an hour fighting with setting the region in GRASS 7.
Finally I discovered that the display region and computational region
are now independent. Is there a way to have the computational region
automatically set to the display region, or do we now have to explicitly
link them each time one or the other changes? If there's no way to link
them automatically, is there a way to 'set computational region extent
from display' from the command line?
Hi Tyler,
I don't think something has been changed. Computational region (extent +
resolution) was always a GRASS core concept. And the "display" region
(using your "term") was always different, meaning, zoom in/out and
pan-ing maps in a display never altered the actual region extent and
resolution.
In the newer GUI there is a nice button for this, right after the
classic button "Zoom to selected map layer(s)" which is, of course,
labeled "Zoom to computational region extent".
The other relevant nice feature is to activate the "Show comp. extent"
in the bottom bar (in any wx Map Display window).
What else is there? After playing with a map in a wx Map Disaply window,
there are a few options "Set computational region from...". Well, not
something that you wouldn't know about. I just mention them for the sake
of completeness.
All in all, I don't think there is a way to link automatically any
change in the display only (zoom actions, panning) with the actual
computational region. If there is, I'd be happy to learn something new.
In fact, I don't think it would be smart. That is, I am used to it,
so maybe I am just too blind to see in another way. The user has to know
when he wants to change the computational region's extent, which will be
the extent of the output of *any* raster operation.
* Tyler Smith <tyler@plantarum.ca> [2015-04-13 16:43:05 -0400]:
> Hi,
>
> I've just spent an hour fighting with setting the region in GRASS 7.
> Finally I discovered that the display region and computational region
> are now independent. Is there a way to have the computational region
> automatically set to the display region, or do we now have to explicitly
> link them each time one or the other changes? If there's no way to link
> them automatically, is there a way to 'set computational region extent
> from display' from the command line?
Right, I forgot the cli part: that's what the g.region module is doing.
* Tyler Smith <tyler@plantarum.ca> [2015-04-13 16:43:05 -0400]:
Hi,
I've just spent an hour fighting with setting the region in GRASS 7.
Finally I discovered that the display region and computational region
are now independent. Is there a way to have the computational region
automatically set to the display region, or do we now have to explicitly
link them each time one or the other changes?
This has to be done explicitely, except for the fact that you can ask for the display to always use the computational region's resolution ('Display resolution' in the drop-down menu of the Map Display).
And there is the 'Show comp. extent' that Nikos already mentioned.
If there's no way to link
them automatically, is there a way to 'set computational region extent
from display' from the command line?
Not that I know of. AFAIK, currently the CLI does not have access to the information about the display extent in the Map Display.
Hi Tyler,
I don't think something has been changed. Computational region (extent +
resolution) was always a GRASS core concept. And the "display" region
(using your "term") was always different, meaning, zoom in/out and
pan-ing maps in a display never altered the actual region extent and
resolution.
In the d.mon world this is exactly how things worked: zooming and panning changed the region. The fact that display and region became independent was a little revolution in GRASS history
On Tue, Apr 14, 2015, at 07:41 AM, Moritz Lennert wrote:
In the d.mon world this is exactly how things worked: zooming and
panning changed the region. The fact that display and region became
independent was a little revolution in GRASS history
Ok, thanks for the clarification. I don't know that one way is
necessarily any better than the other, but its going to remain confusing
until I switch all my locations to GRASS 7.
On Tue, Apr 14, 2015 at 5:19 PM, Tyler Smith <tyler@plantarum.ca> wrote:
On Tue, Apr 14, 2015, at 07:41 AM, Moritz Lennert wrote:
In the d.mon world this is exactly how things worked: zooming and
panning changed the region. The fact that display and region became
independent was a little revolution in GRASS history
Ok, thanks for the clarification. I don't know that one way is
necessarily any better than the other, but its going to remain confusing
until I switch all my locations to GRASS 7.
Do you have any suggestions where to add better information? Extend
the bubble help of the zoom icons with a hint?
On Wed, Apr 15, 2015, at 02:11 AM, Markus Neteler wrote:
Do you have any suggestions where to add better information? Extend
the bubble help of the zoom icons with a hint?
Thanks for asking!
Would it be possible to have an alert pop up when you open the
wx-Window, with a checkbox to suppress it in future? Something like:
"""
Note that in GRASS 7 panning and zooming no longer changes the
computational extent, it must be changed explicitly using the button.
don't show this again
"""
That would have the advantages of having the information delivered
exactly when needed, being very hard to miss, and also easily removed
once the message has been received.
The tooltip is also a good idea, but the message may be large enough to
become cumbersome.
On Wed, Apr 15, 2015, at 02:11 AM, Markus Neteler wrote:
Do you have any suggestions where to add better information? Extend
the bubble help of the zoom icons with a hint?
Thanks for asking!
Would it be possible to have an alert pop up when you open the
wx-Window, with a checkbox to suppress it in future? Something like:
"""
Note that in GRASS 7 panning and zooming no longer changes the
computational extent, it must be changed explicitly using the button.
don't show this again
"""
Not to argue against such a popup, but note that this is not something new since grass7. This behaviour is actually quite old and was already present in the preceding GUI, gis.m.
On Wed, Apr 15, 2015, at 04:40 PM, Moritz Lennert wrote:
Not to argue against such a popup, but note that this is not something
new since grass7. This behaviour is actually quite old and was already
present in the preceding GUI, gis.m.
Did the gis.m and d.mon interface differ in grass6 then? I never used
gis.m. Perhaps my use case (calling d.mon from grass-mode in emacs) is
too unusual to warrant making an explicit pop-up/tool-tip.
On Wed, Apr 15, 2015 at 10:57 PM, Tyler Smith <tyler@plantarum.ca> wrote:
On Wed, Apr 15, 2015, at 04:40 PM, Moritz Lennert wrote:
>
> Not to argue against such a popup, but note that this is not something
> new since grass7. This behaviour is actually quite old and was already
> present in the preceding GUI, gis.m.
Did the gis.m and d.mon interface differ in grass6 then? I never used
gis.m.
I am using GRASS GIS for quite a while, and I can't even remember it
(gis.m) behaving differently (might be my poor memory of course), and I am
also very happy it behaves like it does.
Perhaps my use case (calling d.mon from grass-mode in emacs) is
too unusual to warrant making an explicit pop-up/tool-tip.
If one would find such a popup useful (I don't), I would suggest to make it
more general, e.g., "zoom out - only affects display, region remains
unaffected", or just "zoom out - only affects display".
Or, better, "promote" somehow the "Schow comp. region" feature, set by
default or else.
As far as I can tell, (using mostly the command line), appart from the
d.mon related modules in GRASS6.x, which I forgot to
mention and Moritz brought in the discussion, there is nothing new in
GRASS dealing with the region.
[difficult too sort discussion below]
Nikos
--%<---
Moritz Lennert:
> > Not to argue against such a popup, but note that this is not something
> > new since grass7. This behaviour is actually quite old and was already
> > present in the preceding GUI, gis.m.
Paulo van Breugel:
> Did the gis.m and d.mon interface differ in grass6 then? I never used
> gis.m.
Tyler Smith:
I am using GRASS GIS for quite a while, and I can't even remember it
(gis.m) behaving differently (might be my poor memory of course), and I am
also very happy it behaves like it does.
> Perhaps my use case (calling d.mon from grass-mode in emacs) is
> too unusual to warrant making an explicit pop-up/tool-tip.
If one would find such a popup useful (I don't), I would suggest to make it
more general, e.g., "zoom out - only affects display, region remains
unaffected", or just "zoom out - only affects display".
On Thu, Apr 16, 2015, at 02:36 AM, Nikos Alexandris wrote:
Or, better, "promote" somehow the "Show comp. region" feature, set by
default or else.
As far as I can tell, (using mostly the command line), appart from the
d.mon related modules in GRASS6.x, which I forgot to
mention and Moritz brought in the discussion, there is nothing new in
GRASS dealing with the region.
Yes, I understand now that this is not a change between grass6 and
grass7, but the difference between d.mon and gis.m/wx0. The only change
now is that d.mon in grass7 produces a wx window that behaves like the
old gis.m with respect to regions. Changing the computational region on
the command line no longer changes the displayed region in the window,
or vice versa. That was the case with d.mon in grass6 (I've just
confirmed it), but given the comments here I suppose I was an outlier in
not using the gis.m interface.
If that's the case then perhaps no new messages or pop-ups are
necessary, as the main target (me) is now well informed on the issue!
Incidentally, I just tried out the gis.m interface for the first time in
years. I never used it, as my installation always ended up broken in one
way or another, with frequent crashes. Just now, using the default
Debian installation of grass6.4, gis.m couldn't open until I manually
moved some icon gifs into /usr/lib/grass64/etc/gui/icons/grass, and then
the map-chooser dialog failed to open. I know it does work for other
people, and have used it successfully in workshops run on Suse machines,
so I assume I just have very bad luck with this particular interface.
