Kilian Lackhove authored Oct 02, 2014 and Yan Bao committed Feb 27, 2015

This adds a simplified/memory-optimized version of the Shepard algorithm to enable
interpolatin of 3D data. For 1D-data, the original quadratic/linear algorithm are chosen
automatically. In addition, the weights are stored for each point, which might be useful
for e.g running the same interpolation multiple times in future implementations.