Spectral estimation
- cepstrum — cepstrum calculation
 
- cspect — two sided cross-spectral estimate between 2 discrete time signals using
            the correlation method
 
- czt — chirp z-transform algorithm
 
- mese — maximum entropy spectral estimation
 
- pspect — two sided cross-spectral estimate between 2 discrete time signals using
            the Welch's average periodogram method.