Synopsis
		sfnfmiss < in.rsf > out.rsf filt=filt.rsf mask=mask.rsf exact=y verb=n niter=n1 ty=

Parameters
		bool exact=y [y/n] If y, preserve the known data values   file filt= auxiliary input file name   string mask= optional input mask file for known data (auxiliary input file name)   int niter=n1 number of iterations   string ty= Prediction type: all=backward+forward   bool verb=n [y/n] verbosity flag