Synopsis
		sffwi2d < vinit.rsf shots=shots.rsf > vupdates.rsf grads=grads.rsf illums=illums.rsf objs=objs.rsf verb=y precon=n niter=100 rbell=2

Note: This serial FWI is merely designed to help the understanding of
beginners. Enquist absorbing boundary condition (A2) is applied!

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
		DATA          chevron2014/fwi   XJTU          modeling2fwi/marmtest