interpolation, rast.to.sites

[Simon Cox]

I have been told that s.surf.tps is the "best" interpolater available
in grass.  Why is this?  My little experience with it has shown
that it is certainly not quick!  What are its relative merits,
in comparison with idw and idw2?

What is the easiest way to convert a raster to a site list, so
that I can use the s.surf.tps interpolater?  Is it necessary to
go via an ascii intermediate step?

Thanks for your advice.

Simon Cox

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				Dr Simon Cox
         __  L				
      ,~'  L_|\            	Department of Earth Sciences       
   ,-'         \         	Monash University    
   (            \		Clayton  Vic  3168  Australia
   \    ___     /	
    L,~'   "\_x/		Phone +61 3 565 5762
              u   		Fax   +61 3 565 5062
				simon at cerberus.earth.monash.edu.au
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