[GRASSLIST:569]

[lponti at infinito.it]

Dear list,

so far, I have been masking either via MASK or r.mapcalc. 
This way, only cells corresponding to MASK would display 
in the masked raster.

In contrast, now I would like cells corresponding to a 
"mask" NOT to display* in the main raster layer. Is there 
a way to do it?

This is part of a larger issue I am addressing and that I 
will briefly describe. In the attached sample image, you 
see points imported via v.in.ascii and used to get the 
green interpolated raster. Values at black points are 
greater than zero, whereas the value of the white point is 
zero (and it is not used for interpolation since it has no 
biological meaning).

The end result would be to clip out a portion of the green 
raster around the white point. This portion would be 
delimited by midpoints between the white point and the 
closest neighboring black points.

So far, I have been trying to get a vector buffer around 
the white point and then v.to.rast for some kind of 
subsequent clipping (described above*). However I have no 
cue on how to get a comlex shape from neighboring points 
as described. Is there a method already in place to do 
this?

Many thanks in advance and any hints much appreciated,

Luigi

grass6/cygwin user
INFINITO ADSLFLAT 4 MEGA: SOLO 27,90 EURO AL MESE IVA INCLUSA IP STATICO, BANDA GARANTITA 256Kbps ANTIVIRUS E FIREWALL INCLUSI NEL PREZZO

http://adsl.infinito.it



-------------- next part --------------
A non-text attachment was scrubbed...
Name: sample.png
Type: image/png
Size: 24955 bytes
Desc: not available
Url : http://lists.osgeo.org/pipermail/grass-user/attachments/20060404/aac78bc0/sample.png