cIdag()

function out=cIdag(in)

Input:

• in: $N_s$ sets of $d=3$ dimensional data, stored as an $\prod S_k\,\times\,N_s$ matrix

Global variables:

• gbl_S: dimensions of $d=3$ dimensional data sets

Output:

• out: Hermitian conjugate of cI operator applied to in

Produce a function of the above prototype in the file ``cIdag.m''.
Hint: Because the discrete Fourier transform kernel, $\exp 2\pi i \left(n_1 m_1/S_1 + n_2 m_2/S_2 + n_3 m_3/S_3\right)$, is symmetric in $n$ and $m$, the only difference between your codes for cI and cIdag should be the sign of i in the call to fftw.