function f = OFrame(nf)%OFrame(nf): set the output frame to nf.% With no arguments, return the current output frame.%%See also gable.% GABLE, Copyright (c) 1999, University of Amsterdam% Copying, use and development for non-commercial purposes permitted.%          All rights for commercial use reserved; for more information%          contact Leo Dorst (leo@wins.uva.nl).%%          This software is unsupported.persistent of;if nargin==1  of = nf;endf = of;