#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
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Reporter: mlennert | Owner: grass-dev@lists.osgeo.org
Type: defect | Status: new
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Keywords: wxgrass resolution zoom |
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When you set a resolution with g.region and then use the "Zoom to
computational region" option, the resolution indicated in the display is
not equal to the computational region's resolution. See http://geog-
pc40.ulb.ac.be/grass/misc/wxgrass_resolution.png.
It is a feature. The display extent is always aligned to display window
size. "Zoom to computational region" is not exception. Change statusbar
mode to "Comp. extent" and enable "Show". The red colored box representing
computational extent will be centered in the display.
The issue is not only the extent, but also the resolution.
I think it would be useful to have the same system as in gis.m, i.e. with
one display mode aligning to window size and another mode showing the
exact computation region, i.e. respecting extent and resolution.
BTW, would also be nice to add "Zoom to default region" to the menu.
#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
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Reporter: mlennert | Owner: martinl
Type: enhancement | Status: assigned
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Resolution: | Keywords: wxgrass resolution zoom
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Comment (by martinl):
Replying to [comment:3 mlennert]:
> The issue is not only the extent, but also the resolution.
Well, you are speaking about resolution used for the display, the
computational region settings are not changed.
> I think it would be useful to have the same system as in gis.m, i.e.
with one display mode aligning to window size and another mode showing the
exact computation region, i.e. respecting extent and resolution.
Yes, just to find time (now it has low priority in my TODO list) or more
contributors.
> BTW, would also be nice to add "Zoom to default region" to the menu.
#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
--------------------------+-------------------------------------------------
Reporter: mlennert | Owner: martinl
Type: enhancement | Status: assigned
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Resolution: | Keywords: wxgrass resolution zoom
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Comment (by martinl):
From grass-dev ML:
mbarton:
> Martin has implemented something that I think is much more useful and
> easier to understand, and that serves the same purpose. As mentioned
> above, the display always fills the window and has a constant
> resolution. However, the computational region is shown by a red box
> outline. This means you can always tell the region in which map
> modification operations will take place, without having a very
> strange-looking map in the display window, with a lot of white space
> around it.
>
mlennert:
But that brings us back to my original response ("The issue is not only
the extent, but also the resolution."). Yes, the red box is very useful
(although the functionality is maybe a hidden - maybe the "show" text
box should always be visible and read "show extent of computational
region", but a visual information about the resolution is also very
important. It has happened to me often enought that I launch a command
which then takes much longer than expected, only to find out that the
computational region's resolution was much higher than the display's.
Having a mode which allows seeing the exact computational region
settings is, thus, very helpful...No need to make it the default, and
you could possibly hide it a bit to not confuse users, but IMHO, it
should be an option for power users.
----
For now I added new mode to the statusbar called "Comp. region". It shows
extent and resolution of computational region settings. "Comp. extent"
contains only checkbox to show computational extent outline in the
display.
#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
--------------------------+-------------------------------------------------
Reporter: mlennert | Owner: martinl
Type: enhancement | Status: assigned
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Resolution: | Keywords: wxgrass resolution zoom
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Comment (by mlennert):
More info is always better (could be formatted a bit better, with at least
two more commas, but possibly spaces to make coordinates readable), but I
do think a visualisation mode showing the exact computational region would
be far superior. I won't insist though, as I seem to be the only one
asking for this...
#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
--------------------------+-------------------------------------------------
Reporter: mlennert | Owner: martinl
Type: enhancement | Status: assigned
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Resolution: | Keywords: wxgrass resolution zoom
--------------------------+-------------------------------------------------
Comment (by martinl):
Replying to [comment:7 mlennert]:
> More info is always better (could be formatted a bit better, with at
least two more commas, but possibly spaces to make coordinates readable),
Now display region extent is drawn as a blue box inside the computational
region extent, computational region extent inside a display region extent
as a red box. See r30816.
> a check box to turn the computational guide on|off would be nice.
#106: wxgrass: zoom to computational region does not respect resolution set with
g.region
--------------------------+-------------------------------------------------
Reporter: mlennert | Owner: martinl
Type: enhancement | Status: assigned
Priority: major | Milestone: 6.4.0
Component: Python | Version: svn-trunk
Resolution: | Keywords: wxgrass resolution zoom
--------------------------+-------------------------------------------------
Comment (by mlennert):
Michael:
> But there is no point in making the display itself have the same
> resolution (xy pixels) as the map.
Either we are not speaking about the same thing, or I disagree. I do think
that it can be very useful to display the map at more or less the same
resolution as the computation region.
As images sometimes make things clearer, please look at http://geog-
pc40.ulb.ac.be/grass/misc/wxgrass_resolution.png.
As you can see, the computational region's resolution is set to 300. The
xmon-display makes it immediately obvious at which resolution we are
working, whereas the wxgrass-display remains at a resolution of 30, even
after zooming to the computational region.
I think that seeing the resolution used can be very helpful in many
applications, so I still maintain that having a second viewing mode, just
as in gis.m which totally respects the region settings, including
resolution, would be very useful.