sfgsray (2.0-git)
Gauss Seidel iterative solver for phase space escape positions, angle and traveltime

        sfgsray < in.rsf > out.rsf slow=slow.rsf slowz=slowz.rsf slowx=slowx.rsf dslow=dslow.rsf dtout=dtout.rsf iq= niter=50 liter=0 tol=0.000002*nx*nz order=1 verb=n sph=n

string dslow=
auxiliary input file name
file dtout=
auxiliary output file name
int iq=
switch for escape variable 0=x, 1=a, 2=t, 3=z, 4=l, 5=i
int liter=0
number of first iterations with low-order scheme
int niter=50
number of Gauss-Seidel iterations
int order=1
order of upwind
file slow=
auxiliary input file name
file slowx=
auxiliary input file name
file slowz=
auxiliary input file name
bool sph=n [y/n]
true - half-sphere, false - flat B.C. on left/right
float tol=0.000002*nx*nz
accuracy tolerance
bool verb=n [y/n]
verbosity flag