Synopsis
		sfpocs3d < Fin.rsf mask=Fmask.rsf > Fout.rsf verb=n niter=100 pclip=99.

Parameters
		string mask= auxiliary input file name   int niter=100 total number of POCS iterations   float pclip=99. starting data clip percentile (default is 99)   bool verb=n [y/n] verbosity