[GRASSLIST:2940] Re: s.to.rast help

[Kevin Slover]

Andrea, and all,
	I apologize for the size of the last email.  I did not realize the size
until it went out, should be more aware of what I am sending...
	The command that I used was s.to.rast input=test.sites output=test.rast
size=3.  Not sure how much of the other discussion you have heard...the
sites are ~500m apart, and my cell size I set at 100m.  Should cover the
entire area...


Andrea Aime wrote:
> 
> Hi Kevin,
> sorry for posting you a complaint rather than an help, but
> try to consider that some people on the list have only
> dial-up access on a pay per use line, and it's not funny
> to stay 40 minutes on the telephone just to see your postings...
> please, next time try to use ASCII art like Eric, or at
> least compress them in JPEG format... a 50K email is annoying,
> a 3 MB mail like this one is definitely unbearable... if I
> could not delete this mail from my web mail client I would have
> to wait at least 40 minutes to download it!!!
> I hope you will understand our problems...
> 
> More related to your problem: can you post the exact command
> sequenced performed to get that raster file?
> Maybe it's a bug, maybe we just don't
> see something that may become obvious taking a look at the
> commands used to build that file...
> 
> Best regards
> Andrea Aime
> 
> Kevin Slover wrote:
> >
> > Eric,
> > thanks for the response.  I guess it is difficult to explain...You
> > answer has given me a bit more insight on the s.to.rast command.
> > However, with that explanation, it makes it that much more puzzling.
> > Taking your example below, the 0 representing my data point, and the X's
> > representing the "buffered" cells...my data point "cell" is given a NULL
> > value, and the other "buffered" cells are given a value.  I will attach
> > a tif image, which might give more of an explanation of the problem.  I
> > am sure the outputted white areas on the raster are null, as I have done
> > both r.what.rast and r.out.xyz, and get NULL values.  I am sure there is
> > some simple solution to this problem, that I am overlooking some step
> > somewhere, but it is evading me right now.
> > And, as I said in the last email, r.fillnulls doesn't recognize the NULL
> > values, yet they are clearly there...any ideas??
> >
> > > I'm sorry, but it's not clear what the problem is.  The s.to.rast module
> > > creates a cell value for each site it falls within (given the current
> > > region settings).  If you ask for additional cells, the cells grow out
> > > in every direction by the number given.  So, "buffered" by three cells
> > > gives you something the following (for a given site):
> > >
> > >        X X X X X X X
> > >        X X X X X X X
> > >        X X X X X X X
> > >        X X X O X X X
> > >        X X X X X X X
> > >        X X X X X X X
> > >        X X X X X X X
> > >
> > > So, if your sites are 500m apart, with 100m cell size, the edges of the
> > > "buffered" cells will probably colide (and you should get warnings about
> > > this).
> > >
> > > As far as nulls go, are you sure there any remaining?  At the beginning
> > > of the run, the program writes out all cells as NULL.  It then writes
> > > the corresponding sites data cells (as buffered), possibly clobbering
> > > previously written values (aforementioned warning).
> > >
> > > --
> > > Eric G. Miller <egm2 at jps.net>
> >
> > --
> >         LTJG Kevin Slover,NOAA   GIS
> > Specialist/Meteorologist/Oceanographer
> >               Tropical Prediction Center/National Hurricane Center
> >                     11691 SW 17th Street Miami FL 33165
> >                  Work: (305) 229-4456 Fax : (305) 553-1264
> >
> >   ------------------------------------------------------------------------
> >                    Name: example1.tif
> >    example1.tif    Type: TIFF Image (image/tiff)
> >                Encoding: base64
> >
> >                    Name: example2.tif
> >    example2.tif    Type: TIFF Image (image/tiff)
> >                Encoding: base64

-- 
        LTJG Kevin Slover,NOAA   GIS
Specialist/Meteorologist/Oceanographer 
              Tropical Prediction Center/National Hurricane Center
                    11691 SW 17th Street Miami FL 33165
                 Work: (305) 229-4456 Fax : (305) 553-1264