[GRASS-user] extrude vector points

Markus Neteler neteler at itc.it
Fri Aug 24 06:33:44 EDT 2007

Luigi Ponti wrote on 08/23/2007 05:07 PM:
> Dear list,
> Is there a way to "extrude" 2D vector points to 3D points based on
> attribute column values, similar to what I have read v.extrude can do
> with lines? I have tried to use v.extrude with points but an empty 3D
> vector was created.
ciao Luigi:

1. use 'v.db.addcol' to add also an x and y column

2. then upload also x and y to attribute table with 'v.to.db'
   (so you have x,y,z there as *attribute*)

3. run 'v.in.db' to re-generate the point map as 3D map, indicating
   x=xcol y=ycol z=zcol

4. with 'v.db.dropcol' you could now remove the xcol, ycol, zcol columns
   from the new 3D map attribute table as no longer needed


PS: it would be great to have such functionality in v.transform: a new
  parameter "column" which reads z from the attribute table.

ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
ITC -> since 1 March 2007 Fondazione Bruno Kessler

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