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+# Copyright (C) 1997 Kai P. Mueller
+#
+# This file is part of Octave. 
+#
+# Octave is free software; you can redistribute it and/or modify it 
+# under the terms of the GNU General Public License as published by the 
+# Free Software Foundation; either version 2, or (at your option) any 
+# later version. 
+# 
+# Octave is distributed in the hope that it will be useful, but WITHOUT 
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License 
+# for more details.
+# 
+# You should have received a copy of the GNU General Public License 
+# along with Octave; see the file COPYING.  If not, write to the Free 
+# Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
+ 
+function outsys = ugain(n)
+  # function outsys = ugain(n)
+  # Creates a system with unity gain, no states.
+  # This trivial system is sometimes needed to create arbitrary
+  # complex systems from simple systems with buildssic.
+  # Watch out if you are forming sampled systems since "ugain"
+  # does not contain a sampling period.  
+  #
+  # See also: hinfdemo (MIMO H_infinty example, Boeing 707-321 aircraft model)
+
+  # Written by Kai P. Mueller April, 1998
+  # Updates
+  # $Revision: 1.1.1.1 $
+  # $Log: ugain.m,v $
+  # Revision 1.1.1.1  1998/05/19 20:24:10  jwe
+  #
+  # Revision 1.1  1998/05/05 17:04:45  scotte
+  # Initial revision
+  #
+# Revision 1.1  1998/05/04  15:15:37  mueller
+# Initial revision
+#
+  #
+# Initial revision
+#
+
+  if((nargin != 1) || (nargout > 1))
+    usage("outsys = ugain(n)")
+  endif
+  outsys = ss2sys([],[],[],eye(n));
+endfunction