Inverse discrete Fourier transform
ifft(x) is the inverse discrete Fourier transform (DFT) of the Galois vector x. If x is in the Galois field GF(2m), the length of x must be 2m-1.
For an example using ifft, see the reference page for fft.
The Galois field over which this function works must have 256 or fewer elements. In other words, x must be in the Galois field GF(2m), where m is an integer between 1 and 8.