Synopsis
		sfahpef < in.rsf > filt.rsf maskin=mask.rsf a= center= gap= n= dim=ndim na=0 niter=100 verb=y lag= res=

Parameters
		ints a= [dim]   ints center= [dim]   int dim=ndim number of dimensions   ints gap= [dim]   string lag= output file for filter lags   string maskin= optional input mask file (auxiliary input file name)   ints n= [dim]   int na=0 filter size   int niter=100 number of iterations   string res= output residual (optional)   bool verb=y [y/n] verbosity flag