ThinPlateSpline is bugged, proposed fix

[nikjetchev]

Looking at https://github.com/Lasagne/Lasagne/blob/master/lasagne/layers/special.py

function _get_transformed_points_tps

distances = T.switch(T.isnan(log_r_2), r_2 * log_r_2, 0.)

This is a bug -- should be actually T.switch(T.isnan(r_2 * log_r_2), 0., r_2 * log_r_2) because this is the correct order Theano processes switch statement

The fix is very easy -- can somebody make a pull request for this?

[f0k]

because this is the correct order Theano processes switch statement

Thanks, you're right. It seems this isn't covered by the tests. Did you have a test case that exposed the bug, or did you just notice it while reading the code? (For a PR, we should include a test.)

[nikjetchev]

Hi

I noticed this when playing with the code and copy-pasting parts of it and testing how it works. My usage of the TPS was not the canonical Lasagne usage with layers and objects, so it is not so useful for you.