[GRASS-user] integration of sample.c algorithms into r.resample

[Dylan Beaudette]

On Thursday 17 August 2006 09:37, Paul Kelly wrote:
> On Thu, 17 Aug 2006, Dylan Beaudette wrote:
> > On 8/17/06, Paul Kelly <paul-grass at stjohnspoint.co.uk> wrote:
> >> To throw in another suggestion, how about r.resamp.interp? This it would
> >> mean it would be adjacent in the manuals to the other resampling modules
> >> (r.resample and r.resamp.rst) for anyone looking for them, and might
> >> also imply that r.resample (the only one with the full word in its name)
> >> was kind of a default, basic resampler whilst r.resamp.interp and
> >> r.resamp.rst used more advanced and/or interesting resampling methods.
> >
> > That sounds good to me.
>
> Well I would commit it to CVS if it's OK. I briefly edited the r.bilinear
> man page to create a rough manpage for r.resamp.interp (see below): are
> there any glaring errors?
>
> Paul
>
> r.resamp.interp(1)     Grass User's Manual     r.resamp.interp(1)
>
> NAME
>         r.resamp.interp   -  Resamples  raster  map  layers  using
>         interpolation.
>
> SYNOPSIS
>         r.resamp.interp
>
>         r.resamp.interp help
>
>         r.resamp.interp  input=name  output=name   [method=string]
>         [--overwrite]
>
>     Flags:
>         --overwrite
>
>     Parameters:
>         input=name
>             Name of input raster map
>
>         output=name
>             Name for output raster map
>
>         method=string
>             Interpolation method Options: nearest,bilinear,bicubic
>             Default: bilinear
>
> DESCRIPTION
>         r.resamp.interp fills a grid  cell  (raster)  matrix  with
>         interpolated  values  generated  from a set of input layer
>         data points. A choice of three  interpolation  methods  is
>         available;  each  uses  the weighted values of a different
>         number of adjacent cells in the input map to determine the
>         value of each cell in the output map as follows:
>
>                       nearest neighbour (1 cell)
>
>                       bilinear (4 cells)
>
>                       bicubic (12 cells)
>
>         If there is a current working mask, it applies to the out­
>         put raster file.  Only those cells falling within the mask
>         will  be  assigned interpolated values.  The procedure for
>         selection of input data will consider all input data rele­
>         vant  to  interpolating  values at the cell centers of the
>         current geographic region, ignoring the curent mask.  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.
>
> NOTES
>         For  longitude-latitude databases, the interpolation algo­
>         rithm is based on degree fractions, not  on  the  absolute
>         distances  between cell centers.  Any attempt to implement
>         the latter would violate the integrity of  the  interpola­
>         tion method.
>
> SEE ALSO
>         g.region, r.resample, r.resamp.rst
>
> AUTHOR
>         Glynn Clements
>
>         Last changed: $Date: 2003/04/30 15:17:25 $
>
>         Full index
>
> GRASS 6.3.cvs                                  r.resamp.interp(1)

That looks good for now. Thanks!

Cheers,


-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341