[GRASS5] vector point extract script

Radim Blazek blazek at itc.it
Tue Apr 5 03:43:23 EDT 2005

Hamish wrote:
> Hi,
> not knowing enough SQL magic to do this properly*, I've written a little
> script to extract point data from vector points files, including x,y(,z)
> and any selected columns from the db of the same name.
> Assumes db and vector file both have the same category number/order.
> This may well be a bad assumption!
> v.out.ascii.db: 
>   http://grass.gdf-hannover.de/twiki/bin/view/GRASS/GrassAddOns
> [*] I guess make 2 new columns containing x,y values then db.select. How?
> Hamish

paste is probably dangerous, a record aor point can be missing. Isn't it 
better to use join (input must be sorted; use -e for attributes)?

The possibility to export attributes should be added to v.out.ascii, but 
it must be done better than in v.out.ogr. All attributes must be 
selected by one query and read points using category index and keep an 
array of flags if the point was printed. At the end output points 
without attributes.


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