Fix inverse_phat_square

[gnrraphi]

In line

gpt/lib/gpt/algorithms/optimize/fourier_accelerate.py

Line 29 in ea0ed0e

dimensions = list(range(grid.nd))

dimensions can be arbitrary, but line

gpt/lib/gpt/algorithms/optimize/fourier_accelerate.py

Line 47 in ea0ed0e

self.weight[0, 0, 0, 0] = (2.0 * np.pi) ** 2.0 / np.prod(

only works for dimensions equals 4.
This can be fixed by changing self.weight[0, 0, 0, 0] to self.weight[coor[0:1]].

[lehner]

This is no longer correct for multi-rank jobs. g.coordinates returns the global coordinates corresponding to the local view. So it will only on rank 0 do the correct thing. You can instead try "tuple([0]*grid.nd)" as argument?