[GRASS-user] Loss of data using v.net

[Markus Metz]

On Wed, Jan 23, 2013 at 8:22 PM, דור פרידמן <dof1985 at gmail.com> wrote:
> I'm trying to build a network in GRASS in order to find the shortest path
> from any settlement out of 1120 (points), to one waste treatment facility
> out of 27 (points). I plan to use v.net.distance which is designated to this
> purpose, and to define source and destination points using a column called
> "type". In that column I have assigned the settlements layer with the number
> 5 and the treatment facilities with 1.
>
> My problem occurs when I try to create the network using v.net; If I define
> nodes layer (nlayer=2) to be 2, I lose all the points and can't find it,
> even by using v.extract.

What is the output of v.category op=report using the output of v.net?

Markus M

> Otherwise (when nlayer=1) the attributes describing
> type are being auromatically changed to 4, which is the type attribute for
> roads.
>
> Since I have 1120 I find that using from_cat instead of a SQL restriction
> will be too hard.
>
> Any one has an idea why I'm losing this crucial data and how can I prevent
> it from happening?
>
> Thanks in advanced,
>
> Dor
>
>
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