[GRASSLIST:2717] How to get topology of area edges

[Robert Stein]

Hello,

    I'm attempting to read GRASS's ascii vector output into a graphics
display program that I'm writing...  I produce this output (with
v.out.ascii) from a valid GRASS vector layer containing area polygons. What
appears in the resulting data file is a line that denote an area and a
number of points followed by these points... i.e.

A 4
easting northing
...
easting northing
...

However... it appears that each area is not a closed ring as is stated in
some of the documentation... but instead it appears to be an area-edge
representation which is stated in some other documentation :) This is great
with me... and makes a good bit of sense... but I can't seem to find the
information that associates a particular edge with a polygon (i.e. topology)

Can someone point me in the right direction here? Is there some implicit
relationship that I'm missing or don't understand... Thanks in advance for
your help

Rob


Robert Stein
Senior Technical Lead
Indiana Pervasive Technology Labs
rjstein at iu.edu   -   (317) 278-8154