[GRASS-user] mysterious error (WARNING: Cannot open old vector on level 2)

[Maciej Sieczka]

Jarosław Jasiewicz wrote:

Jaroslaw,

> Its about QGIS 0.8 preview 2 (TITAN) installed from deb packages
> Well, most of bugs I saw with qgis happens during workshops with
> students, so that errors shuldn't be mentioned enywhere. In fact I have
> almost 20 students in workshop group so I cannot control everyone, so
> cannot reproduce errors respectively.

I see.

> Most of them (during digitalisation) are simple run-time errors.
> Addationally qgis is the only program I know which can crash linux
> totaly without particular reasons, (only hard reset can help)

There's got to be a reason. Can you elaborate? (we should consider
moving the thread to QGIS user list then).

> I check qgis news regularry, And all errors I had been mentioned, so I
> didn't see  reasons to  mention them again.

Did you report them in their bugtracker, in a way they can make some
use of the report?

> Addationally on my own computer qgis works extremly slow. I work on
> digitzing soil map of Great Poland Lowland (over 2000 areas)

That's not really big. I've been editing in QGIS a GRASS vector a map
of similar size *daily*, for few last months, without any slowdown;
here's the vectors details:

$ v.info -t parcels_15_2zl
nodes=3097
points=0
lines=0
boundaries=3091
centroids=1175
areas=1175
islands=6
faces=0
kernels=0
primitives=4266
map3d=0

Can you specify what is the nature of the "qgis works extremly slow"?
Is that the vectors are rendered slowly (and under what circumstances),
or the backdrop raster, else?

> And opposite Maciek I never had problems with v.digit (in spite of lack of
> experience) but qgis became solower and slower when number of obiects
> incresed.

I've had a major problem with the speed of rendering vectors in QGIS
too (if that's what you mean), but it showed to be due to X server
issues, *maybe* limited to the distro I'm using (Ubuntu 6.06 Dapper).
After fixing my Xorg setup the problem vanished; please see the thread
on QGIS user list [1] and in the QGIS bugtracker [2] (the 2 last
messages). Please let me know whether this is the same issue.

> I thing that one of reasons of my problems is that I install it form
> packages -   but it shouldn't be an argument. And second is that I use
> gnome (GTK), but qgis is based on Qt (KDE) it also shouldn't be a problem.
> 
> It not a criticism

But yes it is. And it's a very good thing, if you can present
argument's supporting your criticism, so that others can benefit from
it (the users - be informed, the devs - be able to fix the problem).
However, if you can't provide details and arguments, you can't have a
clue what is the possible reason of the issue, and you can't be sure it
is in QGIS, can you? I made this mistake in case of the issue with
vectors rendering speed in QGIS myself :).

Maciek

[1]http://www.nabble.com/rendering-current-line-in-Grass-digitizer-is-very-slow-tf1908709.html#a6825237
[2]https://svn.qgis.org/trac/ticket/295