Allow extrapolation in the 2D ThinPlateSplineInterpolator

[julianpopescu]

Hello,

I'm currently working on a project that requires 2D extrapolation using the thin plate spline interpolation.
Apparently the current implementation doesn't allow it, however I've altered the code by commenting out lines 141-145 in
"src/libInterpolate/Interpolators/_2D/ThinPlateSplineInterpolator.hpp" and results seem to be fine based on comparison with matlab.
Is that any chance to officially remove the check in a future release or at least create a branch?

Thanks,
Julian

[CD3]

Yea, none of the interpolators do any extrapolation because I have ran to issues with it in the past and it doesn't really mean much if you get to far away from the data. I could add an option to turn it on with the default set to false.

[julianpopescu]

Hi,
I see your point but this is more of “extrapolate at your own risk” issue. If you have points to extrapolate slightly outside of the fitting data set, I don’t see why exclude those by a hard limit.
In any case your offered option is more than reasonable. Any idea when would you be able to make a new release?

Thank you,
Julian

[CD3]

I don't see being able to work on it any time soon. Would you want to submit a PR?