Synopsis
		sfvelan < Fsemb.rsf cmp=Fcmp.rsf offset=Foff.rsf > Fout.rsf useoffset=y half=y

Parameters
		file cmp= auxiliary input file name   bool half=y [y/n] half or full offset?   file offset= auxiliary input file name   bool useoffset=y [y/n] if irregular offset, pass it