2-D inverse fast Fourier transform

`X = ifft2(`

returns
the two-dimensional
discrete inverse Fourier transform of a matrix using a fast
Fourier transform algorithm. If `Y`

)`Y`

is a multidimensional
array, then `ifft2`

takes the 2-D inverse transform
of each dimension higher than 2. The output `X`

is
the same size as `Y`

.

The

`ifft2`

function tests whether the vectors in a matrix`Y`

are conjugate symmetric in both dimensions. A vector`v`

is conjugate symmetric when the*i*th element satisfies`v(i) = conj(v([1,end:-1:2]))`

. If the vectors in`Y`

are conjugate symmetric in both dimensions, then the inverse transform computation is faster and the output is real.