The iztrans(M) function computes the element-wise inverse Z transform of M.  The result, R, is formed as R[i,j] = iztrans(M[i,j], t, s).

f = iztrans(F) is the inverse Z transform of the scalar F with the default independent variable z.  If F is not a function of z, then F is  assumed to be a function of the independent variable returned by findsym(F,1). The default return is a function of n.

If F = F(n), then iztrans returns a function of k.

iztrans(F,k) makes F a function of the variable k instead of the default n.

iztrans(F,w,k) takes F to be a function of w instead of the default z. The summation is then with respect to k.