Synopsis
		sffraclr2test < vel.rsf fft=fft.rsf left=left.rsf > right.rsf seed=time(NULL eps=1.e-4 npk=20 dt= c0= w0= rev=false mode=0 sign=0 approx=true

Parameters
		approx=true use Tieyuan's approximation   c0= reference velocity   dt= time step   eps=1.e-4 tolerance   file fft= auxiliary input file name   file left= auxiliary output file name   mode=0 mode of propagation: 0 is viscoacoustic (default); 1 is loss-dominated; 2 is dispersion dominated; 3 is acoustic   npk=20 maximum rank   rev=false reverse propagation   seed=time(NULL   sign=0 sign of solution: 0 is positive, 1 is negative   w0= reference frequency