Synopsis
		sfmpidfwi Fvel=Fv.rsf Fd=Fd.rsf Fwavelet=Fw.rsf output=Fdat.rsf output=Finv.rsf Ferr=Ferr.rsf Fmod=Fmod.rsf Fgrad=Fgrad.rsf output=Fimg.rsf function=2 para_type=1 verb=n nb=20 coef=5. acqui_type=1 ns= ds= s0= sz=3 nr=acpar->nx dr=acpar->dx r0=acpar->x0 rz=3 interval=1 fhi=0.5/acpar->dt flo=0. frectx=2 frectz=2 onlygrad=n grad_type=1 rfwi=0 wt1=acpar->t0 wt2=acpar->t0+(acpar->nt-1)*acpar->dt woff1=acpar->r0 woff2=acpar->r0+(acpar->nr-1)*acpar->dr v0=1.5 t0=-1. gain=1 waterz=51 grectx=3 grectz=3 v1=0. v2=10. den1=0. den2=10. niter= conv_error= npair=20 nls=20 factor=10 repeat=5

Parameters
		file Fd= auxiliary input file name   file Ferr= auxiliary output file name   file Fgrad= auxiliary output file name   file Fmod= auxiliary output file name   file Fvel= auxiliary input file name   file Fwavelet= auxiliary input file name   int acqui_type=1 if 1, fixed acquisition; if 2, marine acquisition; if 3, symmetric acquisition   float coef=5. maximum velocity of the medium   float conv_error= final convergence error   float den1=0. lower limit of estimated density or impedance   float den2=10. upper limit of estimated density or impedance   float dr=acpar->dx receiver interval   float ds= shot interval   float factor=10 step length increase factor   float fhi=0.5/acpar->dt high frequency in band, default is Nyquist   float flo=0. low frequency in band, default is zero   int frectx=2 source smoothing in x   int frectz=2 source smoothing in z   int function=2 if 1, forward modeling; if 2, FWI; if 3, RTM   float gain=1 vertical gain power of data residual   int grad_type=1 if 1, velocity; if 2, impedance or density   int grectx=3 gradient smoothing radius in x   int grectz=3 gradient smoothing radius in z   int interval=1 wavefield storing interval   int nb=20 PML boundary width   int niter= iteration number   int nls=20 line search number   int npair=20 number of l-BFGS pairs   int nr=acpar->nx number of receiver   int ns= shot number   bool onlygrad=n [y/n] only calculate gradident or not   file output= auxiliary output file name   int para_type=1 if 1, velocity and density; if 2, velocity and impedance   float r0=acpar->x0 receiver origin   int repeat=5 after how many iterations the step length goes back to 1   int rfwi=0 if 0, fwi gradient; if 1, rfwi gradient with Vp-Ip scale separation   int rz=3 receiver depth   float s0= shot origin   int sz=3 source depth   float t0=-1. starting time for cutting direct wave   float v0=1.5 surface velocity for cutting direct wave   float v1=0. lower limit of estimated velocity   float v2=10. upper limit of estimated velocity   bool verb=n [y/n] verbosity flag   int waterz=51 water layer depth   float woff1=acpar->r0 window data residual: rmin   float woff2=acpar->r0+(acpar->nr-1)*acpar->dr window data residual: rmax   float wt1=acpar->t0 window data residual: tmin   float wt2=acpar->t0+(acpar->nt-1)*acpar->dt window data residual: tmax