- Extend `Interp` class to provide multilinear (N-D) interpolation - See resources cited by: https://docs.scipy.org/doc/scipy/reference/generated/scipy.interpolate.RegularGridInterpolator.html - https://www.ams.org/journals/mcom/1988-50-181/S0025-5718-1988-0917826-0/S0025-5718-1988-0917826-0.pdf
Interpclass to provide multilinear (N-D) interpolation