new file mode 100644
--- /dev/null
+++ b/scripts/control/com2str.m
@@ -0,0 +1,76 @@
+# Copyright (C) 1998 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 retval = com2str(zz,flg)
+# usage retval = com2str(zz{,flg})
+#  
+# convert complex number to a string
+# zz: complex number
+# flg: format flag
+#      0 (default):            -1, 0, 1,   1i,   1 + 0.5i
+#      1 (for use with zpout): -1, 0, + 1, + 1i, + 1 + 0.5i
+#
+# $Revision: 1.1 $
+
+  if (nargin < 1 | nargin > 2)
+    usage("com2str(zz{,flg})");
+  endif
+  if(nargin == 1)
+    flg = 0;
+  endif
+ 
+  if( !(is_scalar(zz) & is_scalar(flg) ) )
+    error("com2str: arguments must be a scalar.");
+  endif
+
+  if(flg != 0 & flg != 1)
+    error(["Illegal flg value: ",num2str(flg)]);
+  endif
+
+  sgns = "+-";
+  rz = real(zz);
+  iz = imag(zz);
+  az = abs(zz);
+  if(iz == 0)
+    # strictly a real number
+    switch(flg)
+    case(0)
+      retval = num2str(rz);
+    case(1)
+      retval = [ sgns(1+(rz< 0))," ", num2str(abs(rz))];
+    endswitch
+  elseif(rz == 0)
+    # strictly an imaginary number
+    switch(flg)
+    case(0)
+      retval = num2str(iz);
+    case(1)
+      retval = [ sgns(1+(iz< 0))," ", num2str(abs(iz)),"i"];
+    endswitch
+  else
+    # complex number
+    # strictly an imaginary number
+    switch(flg)
+    case(0)
+      retval = [num2str(rz)," ",com2str(i*iz,1)];
+    case(1)
+      retval = [ sgns(1+(rz< 0))," ", num2str(abs(rz))," ",com2str(i*iz,1)];
+    endswitch
+  endif
+  
+endfunction