[GRASS-user] Re: another r.resamp.interp bug report

[Michael Barton]

On Mar 18, 2008, at 4:06 PM, grass-user-request at lists.osgeo.org wrote:

> Date: Tue, 18 Mar 2008 20:21:38 +0100
> From: Nikos Alexandris <nikos.alexandris at felis.uni-freiburg.de>
> Subject: Re: [GRASS-user] r.in.xyz
> To: Edmondo Elisei <edmondo.elisei at gmail.com>
> Cc: grass-user at lists.osgeo.org
> Message-ID: <1205868098.19886.19.camel at vertical>
> 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