Creating MASK from vect

[Stephan Eickschen]

Hi GRASSers,

I would like to create a MASK using a shoreline which I have as a
vector file (ascii or binary) imported to GRASS. Using v.to.rast
results is a raster layer where everything is 0 but the shoreline,
so either everything but the shoreline would be visible or the
other way round :-( What I would like to have is: a mask, which
blanks the sea. Since it is not an island, or a lake, it is not a
closed line, the coastline "enters" at the left (western) end of
my loacation and "leaves" at the right (easter) end. A simple
"is-north-of-decision" will fail.
How can I define an area (comparable like a floodfill - pattern in
image-processing tools), so that I can build up my mask?
Or is there a way to make it more directly from the vectors?
Thanks in advance for any suggestion!

Regards,

        Stephan


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Stephan Eickschen                     Tel. : +49 (0)251 83-34704
Westfaelische Wilhelms-Universitaet   Fax. : +49 (0)251 83-36100
Institute for Geophysics
Research Unit of Physical Glaciology  email: eicksch at uni-muenster.de
Corrensstrasse 24
48149 Muenster
Germany

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