Hi,
I am trying to do something with v.digit in new grass and I found that
it is totally useless (or I miss something). It seems to be impossible
to pan screen without ending digitizing the line!
Regars
Zbigniew
Hi Zbyszek
That's right, v.digit is of not much use in it's actual form. The issue you
mention is not the only problem. This has been discussed a bit in both
grasslist and grass-devel. Also check the bugtracker for other complaints on
v.digit.
v.digit needs a volunteer who'd fix it. Nobody by now.
However there's QGIS which has a very nice plugin for digitizing Grass
layers, very similar to v.digit but more functional, because panning (mapped
to space key, cool) and zooming (mapped to middle mouse key, not really
comfortable IMHO) is possible during digitizing. Works well for me.
If you want to give a try you'll need to build QGIS with Grass. Also if you
want to read Grass rasters as backdrop maps you'll need to rebuild your
GDAL --with grass first, or better build a separate Gdal-Grass plugin
(better, yet I still don't know how to accomplish that 
; I hope somebody
will kindly answer my help request I post yesterday to gdal-dev list).
Maciek
----- Original Message ----- From: "Zbigniew Perski" <perski@us.edu.pl>
To: "GRASSLIST" <GRASSLIST@baylor.edu>
Sent: Tuesday, June 28, 2005 12:08 PM
Subject: [GRASSLIST:7337] v.digit in 6.0
Hi,
I am trying to do something with v.digit in new grass and I found that
it is totally useless (or I miss something). It seems to be impossible
to pan screen without ending digitizing the line!Regars
Zbigniew
> I am trying to do something with v.digit in new grass and I found
> that it is totally useless (or I miss something). It seems to be
> impossible to pan screen without ending digitizing the line!
..
That's right, v.digit is of not much use in it's actual form. The
issue you mention is not the only problem. This has been discussed a
bit in both grasslist and grass-devel.
It works just fine for points and cleaning up topology. I think "not
easy to use for your task" is a more accurate representation. If you
want to pan, you have to end the line, pan, draw another, and then snap
the two together apparently. A pain, but possible.
Also check the bugtracker for other complaints on v.digit.
Note that a lot of those will be for v.digit from GRASS 5, an entirely
different program.
v.digit needs a volunteer who'd fix it. Nobody by now.
Correct; but again, I would say "improve" rather than "fix". For many
tasks it is fully adequate.
However there's QGIS which has a very nice plugin for digitizing Grass
layers,
Correct.
Hamish
Hi,
Thanks a lot for all explanations.
If you
want to pan, you have to end the line, pan, draw another, and then snap
the two together apparently. A pain, but possible.
I know. It is the way that I have applied. I just want to know if there
is better way..
> v.digit needs a volunteer who'd fix it. Nobody by now.
Unfortunately my programming skills are very little...
> However there's QGIS which has a very nice plugin for digitizing Grass
> layers,
Thanks I will also try Qgis for that.
regards
Zbigniew
From: "Hamish" <hamish_nospam@yahoo.com>
> I am trying to do something with v.digit in new grass and I found
> that it is totally useless (or I miss something). It seems to be
> impossible to pan screen without ending digitizing the line!..
That's right, v.digit is of not much use in it's actual form. The
issue you mention is not the only problem. This has been discussed a
bit in both grasslist and grass-devel.It works just fine for points and cleaning up topology. I think "not
easy to use for your task" is a more accurate representation. If you
want to pan, you have to end the line, pan, draw another, and then snap
the two together apparently. A pain, but possible.Also check the bugtracker for other complaints on v.digit.
Note that a lot of those will be for v.digit from GRASS 5, an entirely
different program.
Right. I should have pointed to particular reports.
v.digit needs a volunteer who'd fix it. Nobody by now.
Correct; but again, I would say "improve" rather than "fix". For many
tasks it is fully adequate.
I don't agree that "improve" is a better word, because v.digit suffers from two serious bugs:
1.
Zooming in v.digit changes resolution in region settings:
http://intevation.de/rt/webrt?serial_num=2962&display=History
Big bug I think. I can't see how it is possible to accurately digitize, even points, when your backdrop raster map gets resampled and displayed differently each time you zoom in or out?
(My bugtracker entry is poor here. Please ignore the note about changing the res to a half of it; actually I learned that v.digit changes the resolution much more freely).
2.
If you zoom in/out much v.digit is likely to crash:
http://intevation.de/rt/webrt?serial_num=3047&display=History
Which happened to me many times *exactly* when I was manualy fixing topology. Imagine how badly I was dissapointed when my work gone with the wind for the first time. Then I got used to quiting v.digit from time to time, doing backup and g.region to set a reasonable res (it seems that this crash is connected with the resolution changing by v.digit; maybe when res gets to fine v.digit cannot handle it anymore?) and going back to v.digit. That's very time-ineffective.
I guess that http://intevation.de/rt/webrt?serial_num=3164&display=History refers to the same problem.
Having said it all I conclude v.digit needs fixing, not improving or extending it's capabilities. Which is easy to say and harder to do when only few comitted coders work on Grass, I know. I'm writing this only to clear the things out hopefully, no offence by any means.
However there's QGIS which has a very nice plugin for digitizing Grass
layers,Correct.
If not the QGIS, none digitizing or vectors editing would be possible in GRASS (for me at least).
Maciek