mpi4py-fft is a Python package for computing Fast Fourier
Transforms (FFTs). Large arrays are distributed and communications
are handled under the hood by MPI for Python (mpi4py).
To distribute large arrays we are using a new and completely
generic algorithm that allows for any index set of a
multidimensional array to be distributed. We can distribute
just one index (a slab decomposition), two index sets
(pencil decomposition) or even more for higher-dimensional arrays.

mpi4py-fft comes with its own Python interface to the serial FFTW
library. This interface can be used much like pyfftw, and even for
real-to-real transforms, like discrete cosine or sine transforms.