Michael - I have added an example from the book at the bottom of this
page - please try it and let me know whether it works.
http://skagit.meas.ncsu.edu/~helena/grasswork/grassbookdat07/
ncexternal/demo.txt
Please keep in mind that r.resample* is for reinterpolation of
continuous data to a different resolution not for interpolation from
scattered data (see the equations in the Appendix on what it does)
(r.surf.idw is designed for scattered data input in raster format).
You should convert your points from raster to vector points and use
the v.surf* modules to interpolate.
I hope this helps and let me know if the examples don't work
Helena Mitasova
Associate Professor
Department of Marine, Earth
and Atmospheric Sciences
1125 Jordan Hall, Campus Box 8208
North Carolina State University
Raleigh NC 27695-8208
http://skagit.meas.ncsu.edu/~helena/
On Mar 19, 2008, at 12:30 AM, Michael Barton wrote:
On Mar 18, 2008, at 4:06 PM, [EMAIL PROTECTED] wrote:
Date: Tue, 18 Mar 2008 20:21:38 +0100
From: Nikos Alexandris <[EMAIL PROTECTED]>
Subject: Re: [GRASS-user] r.in.xyz
To: Edmondo Elisei <[EMAIL PROTECTED]>
Cc: [EMAIL PROTECTED]
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain
On Tue, 2008-03-18 at 17:02 +0100, Edmondo Elisei wrote:
5) r.bilinear syntax
r.bilinear input=subset output=subsetsurface --overwrite
For the second part of the test:
I am having trouble to resample with r.resamp.interp
mode=bilinear. But
I think this has to do with the available values (I got only 6 points
imported)
In the manual one can read as well:
Note that for bilinear and bicubic interpolation, cells of the output
raster that cannot be bounded by the appropriate number of input cell
centers are set to null. This could occur due to the input cells
being
outside the current region, being NULL or MASKed.
So, I suppose with a larger sample it shoud feasible.
Nikos,
I just ran into this today. I haven't done any interpolation in a
few months, so I don't know when this bug crept in. I cannot get
any decent maps out of r.resamp.interp. The bilinear and bicubic
routines only produce NAN maps, and the nearest routine creates a
map that is composed only of the input points.
v.surf.bspline hasn't worked in awhile and I'm getting sporadic
crashes (more often than not) with v.surf.rst with no error message
(except for a system one that the program has caused an error).
So for me today, the only interpolation routine that seems to work
out of all the ones in the GRASS toolkit is v.surf.idw--one of the
worst.
Michael
_______________________________________________
grass-dev mailing list
grass-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-dev
_______________________________________________
grass-dev mailing list
grass-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-dev
