Digitizing in GRASS Part II

[Michel Wurtz - ENGEES/CEREG]

Alejandro Imass wrote:
[...]
> If I digitize 3 polygons , one which is contained in the other two
> (intersects the bigger ones), I am obligated to have at least 4 nodes,
[...]
> When I export the above file into GRASS native ASCII format or to
> ARC/INFO ASCII format I get 6 polygons because the system closes the
> polylines at the nodes (it adds new lines between the nodes cutting the
> whole thing in may other polygons.

You get 6 lines, which is true in your drawing : v.out.ascii or
v.out.arc doesn't export polys, only lines...
If you want polygons, you have to use the arc/info buid command
on your lines (in $LOCATION/dig_att, you will have a file of the
same name as your line file that contains the points needed by
Arc/info (and Grass) to build polygons.

If you import your file, you will see that the lines are OK, but
it's only line (white in v.digit) not area limits (blue in v.digit)

-- 
Michel Wurtz    ENGEES - CEREG
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