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--- /dev/null
+++ b/scripts/control/tf2sysl.m
@@ -0,0 +1,34 @@
+# Copyright (C) 1996 A. Scottedward Hodel 
+#
+# 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 vec = tf2sysl(vec)
+# vec = tf2sysl(vec)
+#
+# used internally in tf2sys
+# strip leading zero coefficients to get the true polynomial length
+
+# $Revision: 1.1 $
+
+while( (length(vec) > 1) & (vec(1) == 0) )
+  vec = vec(2:length(vec));
+endwhile
+if(vec(1) == 0)
+  warning("tf2sys: polynomial has no nonzero coefficients!")
+endif
+
+endfunction