Suggest Caution -- spurious effects

[levineza]

I was hesitant, whether or not I should post this; but I feel obligated to at least suggest caution before using this module.

The following is an interpolation of a slice from the middle of a cube of gas from a periodic astrophysical simulation. I used cKDTree and PeriodicCKDTree to interpolate a slice of my irregularly spaced 3D data onto a regular grid. To be clear, these modules were not used in the simulation, just for data analysis.

As can be seen below, the PeriodicCKD module cannot be used as a drop-in replacement for scipy.spatial.cKDTree; it introduces spurious behaviour around the boundaries.

Using cKDTree:

Using PeriodicCKDTree: