[GRASS-dev] [GRASS GIS] #955: v.digit background errors

GDAL · February 18, 2010, 4:09pm

#955: v.digit background errors
-------------------------+--------------------------------------------------
Reporter: clerici | Owner: grass-dev@lists.osgeo.org
Type: defect | Status: new
Priority: normal | Milestone: 6.4.0
Component: default | Version: 6.4.0 RCs
Keywords: | Platform: Linux
Cpu: Unspecified |
-------------------------+--------------------------------------------------
The d.vect command in the Background panel of v.digit gives an error
regarding topology rebuilding[[BR]]
1) I inserted roads_copy (a copy of roads in Spearfish) in the GIS
Manager[[BR]]
2) I entered v.digit by the r.digit/v.digit button.[[BR]]
3) The v.digit GUI was correctly opened and the display was ok.[[BR]]
4) In the background panel the command 'd.vect map=roads_copy@esercizi
color=0:0:0 ..........' is displayed by default.[[BR]]
5) I moved a node in roads_copy.[[BR]]
6) Clicking the Redraw button the following error message was reported in
the Output window(Fig.1.)[[BR]]

Entering v.digit through: Vector>Develop map>Digitize the Background panel
is empty.[[BR]]
I added the command 'd.vect map=roads_copy disp=cat' and I moved a node.
In redrawing, the cat values were not displayed and I had the same error
as in Fig.1.[[BR]]

I entered at the GRASS prompt the command: v.digit map=roads_copy
map=roads_copy bgcmd='d.vect map=roads_copy disp=cat'. Moving a node and
redrawing, the cat values were correctly displayed and two WARNING were
reported in the terminal (Fig.2).

The error is the same with GRASS6.3, 6.4 and 6.5.

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/955>
GRASS GIS <http://grass.osgeo.org>

GDAL · February 18, 2010, 6:45pm

#955: v.digit background errors
----------------------+-----------------------------------------------------
  Reporter: clerici | Owner: grass-dev@lists.osgeo.org
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.0
Component: Vector | Version: 6.4.0 RCs
Resolution: wontfix | Keywords: vector, digitizing
  Platform: All | Cpu: All
----------------------+-----------------------------------------------------
Changes (by mmetz):

  * status: new => closed
  * component: default => Vector
  * platform: Linux => All
  * keywords: => vector, digitizing
  * resolution: => wontfix
  * cpu: Unspecified => All

Comment:

Replying to [ticket:955 clerici]:
> The d.vect command in the Background panel of v.digit gives an error
regarding topology rebuilding[[BR]]

Using the very same vector map that is edited as background does not work
because it gets modified and topology info is only updated when v.digit is
closed. The only way that would work is to update and write out topology
every time something is changed. This is not an option because then
v.digit would be incredibly slow. It also doesn't really make sense
because the vector map to be digitized is displayed anyway.

Therefore...

> 4) In the background panel the command 'd.vect map=roads_copy@esercizi
color=0:0:0 ..........' is displayed by default.[[BR]]

...is this a bug in the tcltk GUI.

> Entering v.digit through: Vector>Develop map>Digitize the Background
panel is empty.[[BR]]
> I added the command 'd.vect map=roads_copy disp=cat' and I moved a node.
In redrawing, the cat values were not displayed and I had the same error
as in Fig.1.[[BR]]

..and this will not work, i.e. produce the error you observed.
>
>
> I entered at the GRASS prompt the command: v.digit map=roads_copy
map=roads_copy bgcmd='d.vect map=roads_copy disp=cat'. Moving a node and
redrawing, the cat values were correctly displayed and two WARNING were
reported in the terminal (Fig.2).

..same as above.

If you want to compare changes, the only option is to first create a copy
of the vector map and use that as background.

As above, this won't fix because v.digit would become even slower than it
is already. If possible, use the new wxGUI digitizer (more features,
faster, less memory).

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/955#comment:1>
GRASS GIS <http://grass.osgeo.org>

GDAL · February 19, 2010, 9:38am

#955: v.digit background errors
----------------------+-----------------------------------------------------
  Reporter: clerici | Owner: grass-dev@lists.osgeo.org
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.0
Component: Vector | Version: 6.4.0 RCs
Resolution: wontfix | Keywords: vector, digitizing
  Platform: All | Cpu: All
----------------------+-----------------------------------------------------
Comment (by clerici):

What's strange is that the procedure runs well on GRASS6.2. With 'd.vect
vectorname disp=cat' as background I can have a very useful updated and
fast display of the category numbers during digitation or editing. The
rebuilding of topology doesn't seem to require more time even with large
vector files.[[BR]]
PS. Actually I cannot use the new wxGUI as I have to write a small manual
for students that attended a preliminary GRASS course two years ago using
the tcltk GUI.
I'll do it sure in future (for the new students).
Thanks.

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/955#comment:2>
GRASS GIS <http://grass.osgeo.org>

GDAL · February 19, 2010, 10:31am

#955: v.digit background errors
----------------------+-----------------------------------------------------
  Reporter: clerici | Owner: grass-dev@lists.osgeo.org
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.0
Component: Vector | Version: 6.4.0 RCs
Resolution: wontfix | Keywords: vector, digitizing
  Platform: All | Cpu: All
----------------------+-----------------------------------------------------
Comment (by hamish):

Replying to [comment:2 clerici]:
> What's strange is that the procedure runs well on GRASS6.2.

IIRC Glynn rewrote it after 6.2, underneath the UI it's a different module
by the same name.

FWIW I had used the same background image trick in 6.2, but I seem to
recall it would crash after digitizing about 100 points or so. So I would
exit and restart often but still got caught every now and then when the
file was resized on the disk to accomodate the new points.

Hamish

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/955#comment:3>
GRASS GIS <http://grass.osgeo.org>