SlabFFT

[AdwardAllan]

hello, How to use slab decomposition for 3D FFT.

[jipolanco]

That's described in the docs, see here for example.

Basically, if you're following the tutorial, you just need to change

pen = Pencil(dims, comm)  # defaults to 2D decomposition in 3D

to

decomp_dims = (3,)  # decompose 3rd dimension only (for example)
pen = Pencil(dims, decomp_dims, comm)