Program sfps2d | 2-D attenuating wavefield simulation using Fourier Pseudo Spectral method 
[SYNOPSIS]
sfps2d < Fv.rsf Qp=FQp.rsf > Fw.rsf nb=20 nt= dt= fm=20.0 kt=nt
[COMMENTS]
for computing fractional laplacian instead of fractional time derivative

[PARAMETERS]
file    | Qp | = |   | 	auxiliary input file name
float   | dt | = |   | 	time sampling interval 
float   | fm | =20.0 |   | 	dominant freq of Ricker wavelet 
int     | kt | =nt |   | 	
int     | nb | =20 |   | 	thickness of sponge ABC 
int     | nt | = |   | 	number of time steps 
[DIRECTORY]
user/pyang
