[GRASSLIST:4315] Re: s.surf.rst output extent (wrap up)

[Thomas Dewez]

Gordon and all,

After much exploration this week-end I finally discovered why the problem
was occurring: the folders tree and files were READ-ONLY !!!

This must be rare for most of you but I had copied on CD the entire
directory tree to compute the interpolation on another PC running Cygwin
and Grass5pre3. Burning data on a CD makes them "Read only". I changed the
property of the files and folders and things were back in order!

Apologies for troubling you with this silly issue, I should have thought
about it earlier...

Thank you all for your contribution

Thomas


On Mon, 19 Aug 2002, Gordon Keith wrote:

> On Thu, 15 Aug 2002 18:58, Thomas Dewez wrote:
> > Dear all,
> >
> > I am puzzled by the output extent of the s.surf.rst command and
> > perhaps one of you would know how to solve the question.
> >
> > I have a sites file containing X, Y, and Z for about 2 million points
> > (same old problem you've probably heard me moan about before). The
> > DEM output always contains the interpolation of the north eastern
> > corner of the file (1800 x 1120 cells). At first, I assumed the
> > region was set wrong. I reset the region to the extent I wanted and
> > still the output was identical.
> >
> > I'll try splitting the sites file in smaller sections but is there
> > something I'm missing?
> 
> I've found the output of s.surf.rst contains values for quite a lot of 
> area for which there is no data. 
> 
> Note the mapmask parameter to s.surf.rst.
> 
> When ever I import data I use s.to.rast first on the same data to create 
> a map to use as a mapmask eg:
> 
> 
> s.in.ascii in=accept.xyz sites=${survey}_accept
> 
> s.to.rast input=${survey}_accept out=${survey}_accept
> 
> s.surf.rst input=${survey}_accept elev=${survey}_bath tension=10 
> zmult=-1 maskmap=${survey}_accept dmin=0.0001
> 
> r.mapcalc "${survey}_bath=if(${survey}_bath < -10, ${survey}_bath, 
> null())"
> 
> 
> The final step sets zero values to null as s.surf.rst also produces an 
> interesting arrangement of zero and null values. (Note I'm working with 
> mid-water bathymetry so all my values are < -10).
> 
> Regards
> Gordon
> 
> -- 
> 
> Gordon Keith
> Programmer/Data Analyst
> Marine Acoustics
> CSIRO Marine Research
> http://www.marine.csiro.au
> 
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