Synopsis
		sfgpufwi < vinit.rsf shots=shots.rsf > vupdates.rsf grads=grads.rsf objs=objs.rsf illums=illums.rsf verb=y precon=n niter=100 rbell=2

Note: You can try other complex boundary condition but we do not
recommend to do so. The main reason is that FWI is to recover
the low-frequency information of the earth model. Low-freq
means that exact absorbing is not necessarilly needed. The
result will be improved with the optimization precedure.
Furthermore, complex boundary condition (such as sponge ABC or
PML) implies more computational cost, which will degrade the
efficiency of FWI.

Parameters
		file grads= auxiliary output file name   file illums= auxiliary output file name   int niter=100 number of iterations   file objs= auxiliary output file name   bool precon=n [y/n] precondition or not   int rbell=2 radius of bell smooth   file shots= auxiliary input file name   bool verb=y [y/n] vebosity

Used In
		XJTU          gpufwi/marmtest primer/marmfwi