Re: Interpol. irregular grid to irregular grid

[Craig Markwardt <craigmnet(at)cow.physics.wisc.edu>]

deja_jlin@my-deja.com writes:
> howdy!
> 
> i'm trying to interpolate data from one irregular
> 2-D grid to another (different) irregular 2-D
> grid:
> 
> - does IDL have any other built-in functions
> besides MIN_CURVE_SURF that can do this?
> - does anyone have any warnings regarding the
> behavior of MIN_CURVE_SURF?
> - has anyone implemented irregular-to-irregular
> interpolations using other algorithms?

Seeing that nobody else has jumped into the fray here, I guess I can
offer some suggestions:

 * you could interpolate onto a regular grid using one of a number of
   functions (TRIGRID, KRIG2D), and then "un"-interpolate using the
   INTERPOLATE function.  Ugly but it probably works.

 * if you have a small number of points you could use some
   distance-based weighted average

 * it really looks like Kriging is doing what you want.  After a quick
   search on Google I found some nice stuff.  It may be that
   KRIG2D.PRO could be modified to do what you want.

Anybody else have ideas?

Good luck!
Craig

-- 
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Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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