Program sfspefvstep | Streaming prediction-error filter with variable step. 
[SYNOPSIS]
sfspefvstep < inp.rsf > out.rsf infil=infil.rsf lag=lag.rsf verb=n na= lambda1= lambda2=0.0f
[PARAMETERS]
string  | infil | = |   | 	initial filter (auxiliary input file name)
string  | lag | = |   | 	variable step (auxiliary input file name)
float   | lambda1 | = |   | 	constant scale parameter in time axis 
float   | lambda2 | =0.0f |   | 	constant scale parameter in space axis 
int     | na | = |   | 	filter size 
bool    | verb | =n |  [y/n] | 	
[DIRECTORY]
user/yliu
