Section: Transforms/Decompositions
y = ifftn(x)
which computes the same-size inverse FFTs for each dimension of x.
Alternately, you can specify the size vector
y = ifftn(x,dims)
where dims is a vector of sizes. The array x is zero padded
or truncated as necessary in each dimension so that the output
is of size dims. The ifftn function is implemented by a sequence
of calls to ifft.