Program sfTesteb | Demo for effective boundary saving in regular grid
[SYNOPSIS]
sfTesteb < Fv.rsf > Fw1.rsf back=Fw2.rsf nb=20 nt= dt= fm=20.0 ft=0 jt=1 ns=1 ng=nx
[COMMENTS]
The sponge absorbing boundary condition is applied for simplicity!
2N-order FD: effective boundary needs N points on each side!
Note: In this demo, 2N=4 (N=2). 

[PARAMETERS]
file    | back | = |   | 	auxiliary output file name
float   | dt | = |   | 	time sampling interval 
float   | fm | =20.0 |   | 	dominant freq of Ricker wavelet 
int     | ft | =0 |   | 	first recorded time 
int     | jt | =1 |   | 	time interval 
int     | nb | =20 |   | 	thickness of sponge ABC 
int     | ng | =nx |   | 	number of receivers 
int     | ns | =1 |   | 	number of shots 
int     | nt | = |   | 	number of time steps 
[DIRECTORY]
user/pyang
