[Gdal-dev] xyz to gdal

[Frank Warmerdam]

Andrey Kiselev wrote:
> On Thu, Jul 22, 2004 at 05:36:59PM +0200, uli wrote:
> 
>>In the meantime I have done exactly what Jason Nielsen proposed by
>>means of an awk script. Although it is thought only for
>>GaussKrueger-System and 5-digit ("%5.1f") z-values, it may be easily
>>adapted to other systems. Frank: It would however be nice to have this
>>format in GDAL, maybe with support for irregularly spaced points...
> 
> 
> I should note that there are many methods of regularization of the
> irregular points. Moreover, those methods are closely related to the
> nature of your data and to the results you are are want to get. So it is
> not so trivial task. If we want to prepare the regularzation module we
> should implement a bunch of the different methods, at least kriging,
> tringulation, inverse distance --- those are come to mind in first of all.

Folks,

Andrey is quite right and this is why I'm not keen to get into the realm
of point to raster interpolation without some substantial funding.

I will add that GRASS does have a variety of point interpolation methods,
though I realize the original request didn't want to go to something that
complex.

I wrote a couple of point interpolators within OpenEV (inverse distance
and a few variants) but they don't necessarily work efficiently for large
numbers of points.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent