DOCUMENTATION

SYNOPSIS

PERL PROGRAM NAME:  SUCEPSTRUM - transform to the CEPSTRal domain				
AUTHOR: Juan Lorenzo (Perl module only)
DATE:   
DESCRIPTION:
Version: 

USE

NOTES

Examples

SEISMIC UNIX NOTES

 SUCEPSTRUM - transform to the CEPSTRal domain				

  sucepstrum <stdin >sdout sign1=1 					

 Required parameters:							
 none									

 Optional parameters:							
 sign1=1			sign in exponent of fft			
 sign2=-1			sign in exponent of ifft		
 dt=from header		sampling interval			
 verbose=1			=0 to stop advisory messages		

 .... phase unwrapping options .....				   	
 mode=ouphase	Oppenheim's phase unwrapping				
		=suphase simple jump detecting phase unwrapping		
 unwrap=1       |dphase| > pi/unwrap constitutes a phase wrapping	
 	 	=0 no phase unwrapping	(in mode=suphase  only)		
 trend=1	remove linear trend from the unwrapped phase	   	
 zeromean=0     assume phase(0)=0.0, else assume phase is zero mean	
 smooth=0      apply damped least squares smoothing to unwrapped phase 
 r=10     ... damping coefficient, only active when smooth=1           

 Notes:								
 The complex log fft of a function F(t) is given by:			
 clogfft(F(t)) = log(FFT(F(t)) = log|F(omega)| + iphi(omega)		
 where phi(omega) is the unwrapped phase. Note that 0< unwrap<= 1.0 	
 allows phase unwrapping to be tuned, if desired. 			

 The ceptrum is the inverse Fourier transform of the log fft of F(t) 	
 F(t_c) =cepstrum(F(t)) = INVFFT[log(FFT(F(t))]			
                        =INVFFT[log|F(omega)| + iphi(omega)]		
 Here t_c is the cepstral time domain. 				

 To facilitate further processing, the sampling interval		
 in quefrency and first quefrency (0) are set in the			
 output header.							

 Caveats: 								
 No check is made that the data ARE real time traces!			

 Use suminphase to make minimum phase representations of signals 	

 Credits:
      CWP: John Stockwell, June 2013 based on
	sufft by:
	CWP: Shuki Ronen, Chris Liner, Jack K. Cohen
	CENPET: Werner M. Heigl - added well log support
	U Montana: Bob Lankston - added m_unwrap_phase feature

 Note: leave dt set for later inversion

 Trace header fields accessed: ns, dt, d1, f1
 Trace header fields modified: ns, d1, f1, trid

CHANGES and their DATES

sub Step

collects switches and assembles bash instructions by adding the program name

sub note

collects switches and assembles bash instructions by adding the program name

sub clear

sub dt

sub mode

sub r

sub sign1

sub sign2

sub smooth

sub trend

sub unwrap

sub verbose

sub zeromean

sub get_max_index

max index = number of input variables -1