vectors: lines to polygons (2)

Agustin Lobo alobo at ija.csic.es
Thu Jun 3 12:19:30 EDT 1999


Sorry, it seems that I pasted a not final version
of my message to my mailing system.
I repeat and hope that it will be more
clear

I have imported a vegetation map of Europe.
It seems that it was digitized as LINES, not
as polygons, which is not very useful for a vegetation map. 
Therefore, I have now a vector map in which the lines should be 
appended to make polygons. I've checked the ascii
file and it is not just
that each polygon is made out of one single line
(i.e., that the last point is not equal to the
first one), so it's not just a question of 
copying the first point at the end of the polygon an
replacing "L" by "A" in the ascii vector format.
It is more complicated as lines have to be combined
into polygons.

The question (and I suspect the answer...):

is there an automatic procedure to combine the
lines into polygons?, i.e., if we have:
 
 AAAAAAADDDDD
 B     A    E
 B     C    E
 D     C    F
 DDDDDDDFFFFF
 
 (where each letter is a line)
 
 transform to  2 polygons

 Thanks (to both mailing list users and mailing list keepers)
 
 Agus
 
 Dr. Agustin Lobo
 Instituto de Ciencias de la Tierra (CSIC)
 Lluis Sole Sabaris s/n
 08028 Barcelona SPAIN
 tel 34 93409 5410
 fax 34 93411 0012
 alobo at ija.csic.es
 http://pangea.ija.csic.es/alobo
 
 



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