Synopsis
		sftfchain < src.rsf > wht.rsf target=tgt.rsf fweight=fwht.rsf match=mch.rsf rect=1 frect=1 niter=0 liter=50

Parameters
		int frect=1 smoothing in frequency   file fweight= auxiliary output file name   int liter=50 number of linear iterations   file match= auxiliary output file name   int niter=0 number of iterations   int rect=1 smoothing in time   file target= auxiliary input file name