[GRASS-user] Intersections on World Map

[ivan marchesini]

hmmm 
really strange...
did you verify the topology of the world map?

v.build map=$map

ciao



Il giorno gio, 01/11/2007 alle 16.11 +0100, Martin Bley ha scritto:
> Hi,
> 
> I still get stucked on an issue using v.overlay. I imported
> a shapefile
> with the world continents (the one from ESRI). Projection
> is Lat-Long. 
> Then I draw a line using v.in.ascii representing a latitude
> e.g.
> 
> VERTI
> L  2 1
>  -180 -80
>  180 -80
>  1 1
> 
> Now I use the following command to merge the intersection
> between the 
> latitude (80 South) and the areas in the world continents
> vector. 
> 
> v.overlay ainput=$vector atype=line alayer=1 binput=World
> btype=area \
>  blayer=1 output=$out operator=and
> 
> Works pretty well so far, until I reach latitude South 75+.
> Intersections doesn't
> match continents anymore (please see attached PNG file).
> 
> I would appreciate any hint. 
> 
> Regards,
> Martin 
> 
> _______________________________________________
> grassuser mailing list
> grassuser at grass.itc.it
> http://grass.itc.it/mailman/listinfo/grassuser
-- 
Ti prego di cercare di non inviarmi files .doc, .xls, .ppt, .dwg.
Preferisco formati liberi.
Please try to avoid to send me  .doc, .xls, .ppt, .dwg files.
I prefer free formats.
http://it.wikipedia.org/wiki/Formato_aperto
http://en.wikipedia.org/wiki/Open_format

Ivan Marchesini
Department of Civil and Environmental Engineering
University of Perugia
Via G. Duranti 93/a 
06125
Perugia (Italy)
Socio fondatore GFOSS "Geospatial Free and Open Source Software" http://www.gfoss.it
e-mail: marchesini at unipg.it
        ivan.marchesini at gmail.com
tel: +39(0)755853760
fax (university): +39(0)755853756
fax (home): +39(0)5782830887
jabber: geoivan73 at jabber.org