Vector to Ascii output

[John Mackenzie]

Hi Joe,

This format is pretty close to the BNA ascii format used by
AtlasGIS.  That format doesn't include the internal point 
(not sure why it's really needed, since the polygon topology is 
already built by the closure), but has the structure (for a
polygon):

name, [name2, name3,] nverts
x1, y1
x2, y2
 ...
x1, y1  

The sign and magnitude of nverts indicates whether the feature is a line 
(nverts < -1), polygon (nverts > 2; last vertex must equal first),
point (nverts = 1) or circle (nverts = 2; vertices are center 
and one point on perimeter).

The v.in.atlas/v.out.atlas contributed modules are available in
the /incoming directory on the moon.  We've used v.in.atlas to import
to GRASS, haven't actually tried v.out.atlas.  Anyway, you may want
to give this a try, maybe just sticking in the internal vertex in the first
line of each feature (which you can extract from GRASS dig_att file) 
or else importing them unlabeled (?) and tagging them in whatever 
GIS you're importing to.  Not the most elegant solution, but should work.

John Mackenzie
U. of Delaware



> Hi All,
> I am trying to import map layers into a Graphic/Map package. The required import format is simialr to that produced by v.out.ascii , but not close enough :-( .
> The format I require is as follows:-
> 

> ......
> 
> Note that the set of points enclose a complete polygon.  Aslo the point WITHIN the polygon ( at the begining of each set) does not have to be the centroid.
> 
> Is there any way I can get such an output from GRASS?? Please mail me if you what more information and ofcourse with ANY suggestions.