[GRASS-user] Contour lines extraction

[Odoardo Zecca]

Hi all,
I need to extract some contour lines from a vector map (imported with
v.in.dwg -z). While  I can do this on the base of their category, it would
be easier to directly select the desired elevations, but I don't know how to
refer to them. With d.what.vect I obtain the following textual output:

GRASS 6.1.cvs (Valledaosta):/media/sda7/zodoardo/cartografia >
d.what.vect-x ma p=dwg0351
Building spatial index ...
 100%

Buttons
 Left:  what's here
 Right: quit

405718.49528848(E) 5051089.77547112(N)

dwg0351 in zodoardo  Line
length 4098.283965
Line height: 560.000000
Layer: 1
category: 15833
driver: dbf
database:
//media/sda7/zodoardo/cartografia/grassdb/Valledaosta/zodoardo/dbf/
table: dwg0351
key column: cat
cat : 15833
entity_nam : POLYLINE
color : 256
weight : -1
layer : 12L04
block :
txt :
Done.

The problem is that "Line height" doesn't appear in the dbf table.
What can I do?

Thanks.

Odoardo

-----------------------
Odoardo Zecca
Institut Agricole Régional
Aosta (It)
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