[GRASS5] Re: Vector points and topology

[Markus Neteler]

On Mon, Jul 04, 2005 at 10:31:21AM +0200, Radim Blazek wrote:
> On 7/1/05, Markus Neteler <neteler at itc.it> wrote:
> > - how to speed up v.out.ogr export (230 minutes for 100k points)
> 
> It has nothing to do with topology. The problem is random access to attributes.
> It is necessary to change v.out.ogr so that it opens select cursor
> for attributes sorted by cat and then it must process geometry 
> in the cats order (using category index) and read attributes sequentialy 
> from the opened select cursor (checking always if the cat is available).

Ok. Is there any example in GRASS to study which changes are needed?

> > - which is the module I should use as reference to explain vector
> >   programming *with* attributes?
> 
> It depends on specific task, v.to.rast, v.extract or v.out.ogr are
> using different
> approach. It is always necessary to take a module doing something similar
> to the task you want to do.

OK.

Markus