Program sffxynpre | FXY non-stationary predictive filtering (with the option of local processing windows). 
[SYNOPSIS]
sffxynpre < Fin.rsf > Fou.rsf verb=n sym=n opt=y fs=n Nfrac=6.0 Ntimes=5.0 pow=0.5 niter=100 n1win=n1 n2win=nx n3win=ny r1=0.5 r2=0.5 r3=0.5 mode=0 nsx=2 nsy=2 rect#=(1,1,...)
[COMMENTS]
with frequency-axis smoothness constraint
with frequency-dependent smoothing

Reference: Wang et al. (2021), Non-stationary predictive filtering for seismic random noise suppression - A tutorial, Geophysics, 86(3), W21-W30. 

[PARAMETERS]
float   | Nfrac | =6.0 |   | 	frequency-dependent smoothing starts from 1/Nfrac * (Nyquist frequency) 
float   | Ntimes | =5.0 |   | 	Maximum smoothing radius is Ntimes*(reference smoothing radius) 
bool    | fs | =n |  [y/n] | 	y, determine frequency-dependent smoothing 
int     | mode | =0 |   | 	predictive filtering mode; default: non-stationary
int     | n1win | =n1 |   | 	first window length
int     | n2win | =nx |   | 	second window length
int     | n3win | =ny |   | 	second window length
int     | niter | =100 |   | 	number of iterations 
int     | nsx | =2 |   | 	number of shifts in non-causal prediction filtering 
int     | nsy | =2 |   | 	number of shifts in non-causal prediction filtering 
bool    | opt | =y |  [y/n] | 	y, determine optimal size for efficiency 
float   | pow | =0.5 |   | 	fraction parameter
float   | r1 | =0.5 |   | 	first overlapping ratio
float   | r2 | =0.5 |   | 	second overlapping ratio
float   | r3 | =0.5 |   | 	third overlapping ratio
int     | rect# | =(1,1,...) |   | 	smoothing radius on #-th axis 
bool    | sym | =n |  [y/n] | 	y, symmetric scaling for Hermitian FFT 
bool    | verb | =n |  [y/n] | 	Verbosity flag 
[DIRECTORY]
user/chenyk
