Inverse Zak transform.
SIG=izak(DZT)
N by M matrix of Zak samples.
Output signal (M*N,1) containing the inverse Zak transform.
izak computes the inverse Zak transform of matrix DZT.
sig=fmlin(256); DZT=zak(sig); sigr=izak(DZT); norm(sig-sigr)