Ryan May wrote:
Stefan van der Walt wrote:
On Tue, Sep 26, 2006 at 11:19:37AM -0500, Ryan May wrote:
Is there function for doing a simple bilinear interpolation in scipy? I tried the interpolate.interp2d routines, but it appears that it uses B-splines even when kind='linear' is specified. (I wouldn't otherwise care except that my class assignment explicitly says to use bilinear.) I'm speaking under correction, but if you choose 'linear', b-splines of degree 1 (i.e. straight lines) are used and you are doing linear interpolation.
That's what I kinda thought, but using 'linear' for interp2d didn't give me the same answer as when I performed the calculation manually. I'll have to see what I can find on this...
Ok, if I select the 4 points surrounding the location of interest, interp2d gives me the value I get with manually calculating a bilinear interpolation. However if I use the whole field (or even 9 points instead of 4), I get a different answer. I _know_ I wouldn't expect this for bilinear interpolation, and it would seem to imply that even _linear_ B-splines uses the information from additional points. Am I missing something here, or are the methods just not truly equivalent? Ryan -- Ryan May Graduate Research Assistant School of Meteorology University of Oklahoma rmay@rossby.ou.edu