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changeset 3400:18366d37e7dd

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[project @ 1999-12-22 23:36:09 by jwe]
author jwe
date Wed, 22 Dec 1999 23:36:14 +0000
parents e665633c76af
children 1b782f9cecfe
files scripts/ChangeLog scripts/control/DEMOcontrol.m scripts/control/bddemo.m scripts/control/bode.m scripts/control/controldemo.m scripts/control/d2c.m scripts/control/dgkfdemo.m scripts/control/fir2sys.m scripts/control/frdemo.m scripts/control/is_dgkf.m scripts/control/is_stabilizable.m scripts/control/minfo.m scripts/control/moddemo.m scripts/control/polyout.m scripts/control/sysconnect.m scripts/control/sysrepdemo.m scripts/control/tf2sys.m scripts/control/tfout.m scripts/control/tzero.m scripts/control/zp2sys.m scripts/control/zpout.m scripts/image/loadimage.m src/ChangeLog src/lex.l
diffstat 24 files changed, 299 insertions(+), 254 deletions(-) [+]
line wrap: on
line diff
--- a/scripts/ChangeLog	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/ChangeLog	Wed Dec 22 23:36:14 1999 +0000
@@ -1,6 +1,31 @@
 1999-12-22  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
+	* control/d2c.m: Use double quotes instead of single quotes for
+	string constants.
+	* control/dgkfdemo.m: Likewise.
+	* control/fir2sys.m: Likewise.
+	* control/frdemo.m: Likewise.
+	* control/moddemo.m: Likewise.
+	* control/minfo.m: Likewise.
+	* control/is_stabilizable.m: Likewise.
+	* control/is_dgkf.m: Likewise.
+	* control/polyout.m: Likewise.
+	* control/sysconnect.m: Likewise.
+	* control/sysrepdemo.m: Likewise.
+	* control/tf2sys.m: Likewise.
+	* control/tfout.m: Likewise.
+	* control/zp2sys.m: Likewise.
+	* control/zpout.m: Likewise.
+	* control/tzero.m: Likewise.
+
+	* control/DEMOcontrol.m: Handle moddemo case too.
+
+	* image/loadimage.m: Use double quotes instead of single quotes
+	for string constants.  Use sprintf instead of square brackets to
+	construct string.
+
 	* control/DEMOcontrol.m: Formatting tweaks.
+	* control/fir2sys.m: Likewise.
 
 1999-12-17  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
--- a/scripts/control/DEMOcontrol.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/DEMOcontrol.m	Wed Dec 22 23:36:14 1999 +0000
@@ -60,6 +60,7 @@
     		"Block diagram manipulations",
     		"Frequency response functions",
     		"State space analysis functions",
+    		"System model manipulations",
     		"Root locus functions",
 		"LQG/H2/Hinfinity functions",
     		"End");
@@ -70,9 +71,10 @@
       case (2) bddemo ();
       case (3) frdemo ();
       case (4) analdemo ();
-      case (5) rldemo ();
-      case (6) dgkfdemo ();
-      case (7) return;
+      case (5) moddemo ();
+      case (6) rldemo ();
+      case (7) dgkfdemo ();
+      case (8) return;
     endswitch
 
   endwhile
--- a/scripts/control/bddemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/bddemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -59,7 +59,7 @@
       prompt
       help syssub
       prompt
-      disp('Example #1, \n')
+      disp("Example #1, \n")
       cmd = "sys1 = tf2sys([1 -1],[1 2 1]);";
       run_cmd
       cmd = "sys2 = tf2sys([1 -1],[1 2 3]);";
--- a/scripts/control/bode.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/bode.m	Wed Dec 22 23:36:14 1999 +0000
@@ -186,7 +186,7 @@
       if (gnuplot_has_multiplot)
         subplot(2,1,2);
       else
-        prompt('Press any key for phase plot');
+        prompt("Press any key for phase plot");
       endif
       axvec = axis2dlim([vec(w),vec(phase)]);
       axvec(1:2) = wv;
--- a/scripts/control/controldemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/controldemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -22,41 +22,6 @@
 ## Author: David Clem
 ## Created: August 15, 1994
 
-function DEMOcontrol ()
-
-  disp(' O C T A V E    C O N T R O L   S Y S T E M S   T O O L B O X')
-
-  while (1)
-    clc
-    k = 0;
-    while (k > 8 || k < 1),
-      k = menu("Octave Controls System Toolbox Demo", ...
-	'System representation', ...
-    	'Block diagram manipulations ', ...
-    	'Frequency response functions ', ...
-    	'State space analysis functions ', ...
-    	'System model manipulations ', ...
-    	'Root locus functions ', ...
-	'LQG/H2/Hinfinity functions ', ...
-    	'End');
-
-    endwhile
-    if(k == 1)
-      sysrepdemo
-    elseif (k == 2)
-      bddemo
-    elseif (k == 3)
-      frdemo
-    elseif (k == 4)
-      analdemo
-    elseif (k == 5)
-      moddemo
-    elseif (k == 6)
-      rldemo
-    elseif (k == 7)
-      dgkfdemo
-    elseif (k == 8)
-      return
-    endif
-  endwhile
+function controldemo ()
+  DEMOcontrol ();
 endfunction
--- a/scripts/control/d2c.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/d2c.m	Wed Dec 22 23:36:14 1999 +0000
@@ -174,8 +174,8 @@
         for ii=1:rows(Mtop)
           for jj=1:columns(Mtop)
   	  DMall(ii,jj) = Mall(ii,jj) + geps;
-            GrMall(ii,jj) = norm(Amat - expm(DMall*T),'fro') ...
-  	    - norm(Amat-expm(Mall*T),'fro');
+            GrMall(ii,jj) = norm (Amat - expm (DMall*T), "fro") ...
+  		- norm (Amat - expm (Mall*T), "fro");
       	  DMall(ii,jj) = Mall(ii,jj);
           endfor
         endfor
--- a/scripts/control/dgkfdemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/dgkfdemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -30,45 +30,45 @@
   page_screen_output = 1;
   while (1)
     clc
-    menuopt=0;
-    while(menuopt > 10 || menuopt < 1)
-      menuopt = menu('Octave H2/Hinfinity options demo', ...
-	    'LQ regulator', ...
-	    'LG state estimator', ...
-	    'LQG optimal control design', ...
-	    'H2 gain of a system', ...
-	    'H2 optimal controller of a system', ...
-	    'Hinf gain of a system', ...
-	    'Hinf optimal controller of a SISO system', ...
-	    'Hinf optimal controller of a MIMO system', ...
-	    'Discrete-time Hinf optimal control by bilinear transform', ...
-	    'Return to main demo menu');
+    sel = 0;
+    while (sel > 10 || sel < 1)
+      sel = menu ("Octave H2/Hinfinity options demo",
+		  "LQ regulator",
+		  "LG state estimator",
+		  "LQG optimal control design",
+		  "H2 gain of a system",
+		  "H2 optimal controller of a system",
+		  "Hinf gain of a system",
+		  "Hinf optimal controller of a SISO system",
+		  "Hinf optimal controller of a MIMO system",
+		  "Discrete-time Hinf optimal control by bilinear transform",
+		  "Return to main demo menu");
     endwhile
-    if (menuopt == 1)
-      disp('Linear/Quadratic regulator design:')
-      disp('Compute optimal state feedback via the lqr command...')
+    if (sel == 1)
+      disp("Linear/Quadratic regulator design:")
+      disp("Compute optimal state feedback via the lqr command...")
       help lqr
-      disp(' ')
-      disp('Example:')
+      disp(" ")
+      disp("Example:")
       A = [0, 1; -2, -1]
       B = [0; 1]
       Q = [1, 0; 0, 0]
       R = 1
       disp("Q = state penalty matrix; R = input penalty matrix")
       prompt
-      disp('Compute state feedback gain k, ARE solution P, and closed-loop')
-      disp('poles as follows:');
+      disp("Compute state feedback gain k, ARE solution P, and closed-loop")
+      disp("poles as follows:");
       cmd = "[k, p, e] = lqr(A,B,Q,R)";
       run_cmd
       prompt
       disp("A similar approach can be used for LTI discrete-time systems")
       disp("by using the dlqr command in place of lqr (see LQG example).")
-    elseif (menuopt == 2)
-      disp('Linear/Gaussian estimator design:')
-      disp('Compute optimal state estimator via the lqe command...')
+    elseif (sel == 2)
+      disp("Linear/Gaussian estimator design:")
+      disp("Compute optimal state estimator via the lqe command...")
       help lqe
-      disp(' ')
-      disp('Example:')
+      disp(" ")
+      disp("Example:")
       A = [0, 1; -2, -1]
       disp("disturbance entry matrix G")
       G = eye(2)
@@ -79,16 +79,16 @@
       disp("SigW = input disturbance intensity matrix;")
       disp("SigV = measurement noise intensity matrix")
       prompt
-      disp('Compute estimator feedback gain k, ARE solution P, and estimator')
-      disp('poles via the command: ')
+      disp("Compute estimator feedback gain k, ARE solution P, and estimator")
+      disp("poles via the command: ")
       cmd = "[k, p, e] = lqe(A,G,C,SigW,SigV)";
       run_cmd
       disp("A similar approach can be used for LTI discrete-time systems")
       disp("by using the dlqe command in place of lqe (see LQG example).")
-    elseif (menuopt == 3)
-      disp('LQG optimal controller of a system:')
-      disp('Input accepted as either A,B,C matrices or in system data structure form')
-      disp('in both discrete and continuous time.')
+    elseif (sel == 3)
+      disp("LQG optimal controller of a system:")
+      disp("Input accepted as either A,B,C matrices or in system data structure form")
+      disp("in both discrete and continuous time.")
       disp("Example 1: continuous time design:")
       prompt
       help lqg
@@ -142,9 +142,9 @@
       Acl_poles = sortcom(eig(Acl))
       disp("Predicted poles from design = union(Er,Ee)")
       pred_poles = sortcom([Er;Ee])
-    elseif (menuopt == 4)
-      disp('H2 gain of a system: (Energy in impulse response)')
-      disp('Example 1: Stable plant:')
+    elseif (sel == 4)
+      disp("H2 gain of a system: (Energy in impulse response)")
+      disp("Example 1: Stable plant:")
       cmd = "A = [0, 1; -2, -1]; B = [0; 1]; C = [1, 0]; sys_poles = eig(A)";
       run_cmd
       disp("Put into Packed system form:")
@@ -161,7 +161,7 @@
       plot(tt,ht)
       title("impulse response of example plant")
       prompt
-      disp('Example 2: unstable plant')
+      disp("Example 2: unstable plant")
       cmd = "A = [0, 1; 2, 1]";
       eval(cmd);
       cmd = "B = [0; 1]";
@@ -171,18 +171,18 @@
       cmd = "sys_poles = eig(A)";
       run_cmd
       prompt
-      disp('Put into system data structure form:')
+      disp("Put into system data structure form:")
       cmd="Bsys = ss2sys(A,B,C);";
       run_cmd
-      disp('Evaluate 2-norm:')
+      disp("Evaluate 2-norm:")
       cmd = "BsysH2 = h2norm(Bsys)";
       run_cmd
-      disp(' ')
-      prompt('NOTICE: program returns a value without an error signal.')
-      disp('')
+      disp(" ")
+      prompt("NOTICE: program returns a value without an error signal.")
+      disp("")
 
-    elseif (menuopt == 5)
-      disp('H2 optimal controller of a system: command = h2syn:')
+    elseif (sel == 5)
+      disp("H2 optimal controller of a system: command = h2syn:")
       prompt
       help h2syn
       prompt
@@ -244,46 +244,46 @@
       prompt
       disp("Related functions: is_dgkf, is_controllable, is_stabilizable,")
       disp("                is_observable, is_detectable")
-    elseif (menuopt == 6)
-      disp('Hinfinity gain of a system: (max gain over all j-omega)')
-      disp('Example 1: Stable plant:')
+    elseif (sel == 6)
+      disp("Hinfinity gain of a system: (max gain over all j-omega)")
+      disp("Example 1: Stable plant:")
       cmd = "A = [0, 1; -2, -1]; B = [0; 1]; C = [1, 0]; sys_poles = eig(A)";
       run_cmd
-      disp('Pack into system format:')
+      disp("Pack into system format:")
       cmd = "Asys = ss2sys(A,B,C);";
       run_cmd
-      disp('The infinity norm must be computed iteratively by')
-      disp('binary search.  For this example, we select tolerance tol = 0.01, ')
-      disp('min gain gmin = 1e-2, max gain gmax=1e4.')
-      disp('Search quits when upper bound <= (1+tol)*lower bound.')
+      disp("The infinity norm must be computed iteratively by")
+      disp("binary search.  For this example, we select tolerance tol = 0.01, ")
+      disp("min gain gmin = 1e-2, max gain gmax=1e4.")
+      disp("Search quits when upper bound <= (1+tol)*lower bound.")
       cmd = "tol = 0.01; gmin = 1e-2; gmax = 1e+4;";
       run_cmd
       cmd = "[AsysHinf,gmin,gmax] = hinfnorm(Asys,tol,gmin,gmax)"
       run_cmd
       disp("Check: look at max value of magntude Bode plot of Asys:");
       [M,P,w] = bode(Asys);
-      xlabel('Omega')
-      ylabel('|Asys(j omega)| ')
+      xlabel("Omega")
+      ylabel("|Asys(j omega)| ")
       grid();
       semilogx(w,M);
       disp(["Max magnitude is ",num2str(max(M)), ...
 	", compared with gmin=",num2str(gmin)," and gmax=", ...
         num2str(gmax),"."])
       prompt
-      disp('Example 2: unstable plant')
+      disp("Example 2: unstable plant")
       cmd = "A = [0, 1; 2, 1]; B = [0; 1]; C = [1, 0]; sys_poles = eig(A)";
       run_cmd
       disp("Pack into system format:")
       cmd = "Bsys = ss2sys(A,B,C);";
       run_cmd
-      disp('Evaluate with BsysH2 = hinfnorm(Bsys,tol,gmin,gmax)')
+      disp("Evaluate with BsysH2 = hinfnorm(Bsys,tol,gmin,gmax)")
       BsysH2 = hinfnorm(Bsys,tol,gmin,gmax)
-      disp(' ')
-      disp('NOTICE: program returns a value without an error signal.')
-      disp('')
+      disp(" ")
+      disp("NOTICE: program returns a value without an error signal.")
+      disp("")
 
-    elseif (menuopt == 7)
-      disp('Hinfinity optimal controller of a system: command = hinfsyn:')
+    elseif (sel == 7)
+      disp("Hinfinity optimal controller of a system: command = hinfsyn:")
       prompt
       help hinfsyn
       prompt
@@ -332,19 +332,19 @@
       prompt
       disp("Related functions: is_dgkf, is_controllable, is_stabilizable,")
       disp("                   is_observable, is_detectable, buildssic")
-    elseif (menuopt == 8)
-      disp('Hinfinity optimal controller of MIMO system: command = hinfsyn:')
+    elseif (sel == 8)
+      disp("Hinfinity optimal controller of MIMO system: command = hinfsyn:")
       prompt
       help hinfsyn
       prompt
       disp("Example system: Boeing 707-321 airspeed/pitch angle control")
       disp(" ")
       hinfdemo
-    elseif (menuopt == 9)
+    elseif (sel == 9)
       disp("Discrete time H-infinity control via bilinear transform");
       prompt
       dhinfdemo
-    elseif (menuopt == 10)
+    elseif (sel == 10)
       return
     endif
     prompt
--- a/scripts/control/fir2sys.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/fir2sys.m	Wed Dec 22 23:36:14 1999 +0000
@@ -77,22 +77,29 @@
 
   ## Test for the correct number of input arguments
   if (nargin < 1 | nargin > 4)
-    usage('sys=fir2sys(num[,tsam,inname,outname])');
+    usage ("sys = fir2sys(num [, tsam, inname, outname])");
   endif
 
   ## let tf2sys do the argument checking
   den = [1,zeros(1,length(num)-1)];
 
   ## check sampling interval (if any)
-  if(nargin <= 1)               tsam = 1;		# default 
-  elseif (isempty(tsam))        tsam = 1;		endif
+  if (nargin <= 1)
+    tsam = 1;		# default 
+  elseif (isempty(tsam))
+    tsam = 1;
+  endif
 
   ## Set name of input
-  if(nargin < 3)  inname = sysdefioname(1,"u");        endif
+  if (nargin < 3)
+    inname = sysdefioname (1, "u");
+  endif
 
   ## Set name of output
-  if(nargin < 4)  outname = sysdefioname(1,"y"); 	endif
+  if (nargin < 4)
+    outname = sysdefioname (1, "y");
+  endif
 
-  sys = tf2sys(num,den,tsam,inname,outname);
+  sys = tf2sys (num, den, tsam, inname, outname);
   
 endfunction
--- a/scripts/control/frdemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/frdemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -33,11 +33,11 @@
   j = 0;
   while (j != 4)
     disp("");
-    j = menu("Octave Controls Systems Toolbox Frequency Response Demo",...
-             'Bode analysis (bode)',...
-             'Nyquist analysis (nyquist)',...
-	     "Nichols analysis (nichols)", ...
-             'Return to main demo menu');
+    j = menu("Octave Controls Systems Toolbox Frequency Response Demo",
+             "Bode analysis (bode)",
+             "Nyquist analysis (nyquist)",
+	     "Nichols analysis (nichols)", 
+             "Return to main demo menu");
    
     if (j == 1)
       k1 = 0;
@@ -45,11 +45,11 @@
         disp("\n");
         clc
 
-        k1 = menu("Bode analysis (bode)",...
-                  'Continuous system bode analysis',...
-                  'Discrete system bode analysis',...
-                  'Bode command description', ...
-                  'Return to frdemo menu');
+        k1 = menu("Bode analysis (bode)",
+                  "Continuous system bode analysis",
+                  "Discrete system bode analysis",
+                  "Bode command description", 
+                  "Return to frdemo menu");
        
         if( k1 == 1 )
           disp(" ")
@@ -147,7 +147,7 @@
           eval(cmd);
           disp("\nNotice that there are now 2 inputs and 2 outputs, and that it did");
  	  disp("not matter what form the two systems were in when they were grouped.");
-          disp(["\nTo view the system\'s bode plots, execute the",...
+          disp(["\nTo view the system's bode plots, execute the",
         	" following command:\n"])
           cmd = "bode(sys_mimo);";
           run_cmd;
@@ -311,11 +311,11 @@
         disp("")
         clc;
 
-        k2 = menu("Nyquist analysis (Nyquist)",...
-                  'Continuous system nyquist analysis',...
-        	  'Discrete system nyquist analysis',...
-        	  'Mixed system nyquist analysis',...
-                  'Return to frdemo menu');
+        k2 = menu("Nyquist analysis (Nyquist)",
+                  "Continuous system nyquist analysis",
+        	  "Discrete system nyquist analysis",
+        	  "Mixed system nyquist analysis",
+                  "Return to frdemo menu");
 
         if( k2 == 1 )
           disp("")
--- a/scripts/control/is_dgkf.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/is_dgkf.m	Wed Dec 22 23:36:14 1999 +0000
@@ -151,7 +151,7 @@
 
   [A,B,C,D] = sys2ss(Asys);
   ## scale input/output for numerical reasons
-  if(norm(C,'fro')*norm(B,'fro') == 0)
+  if(norm (C, "fro") * norm (B, "fro") == 0)
     error("||C||*||B|| = 0; no dynamic connnection from inputs to outputs");
   endif
   xx = sqrt(norm(B, Inf) / norm(C, Inf));
--- a/scripts/control/is_stabilizable.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/is_stabilizable.m	Wed Dec 22 23:36:14 1999 +0000
@@ -75,7 +75,7 @@
     ## now use an ordered Schur decomposition to get an orthogonal
     ## basis of the unstable subspace...
     n = rows(a);
-    [ua,s] = schur(-(a+eye(n)*tol),'A');
+    [ua, s] = schur (-(a+eye(n)*tol), "A");
     k = sum( real(eig(a)) >= 0 );	# count unstable poles 
 
     if( k > 0 )
--- a/scripts/control/minfo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/minfo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -39,7 +39,7 @@
   warning("minfo: obsolete.  Use sys2ss, sys2tf, or sys2zp.");
     
   if (nargin ~= 1 )
-    disp('MINFO: Wrong number of arguments')
+    disp ("MINFO: Wrong number of arguments")
     systype = nout = nin = ncstates = ndstates = [];
   endif
   
--- a/scripts/control/moddemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/moddemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -33,173 +33,173 @@
 
   while (1)
     clc
-    disp('Octave Model Manipulations Demo')
-    disp('=======================================')
-    disp('  1)  Perform continuous to discrete time conversion (c2d)')
-    disp('  2)  Convert from state space to zero / pole form (ss2zp)')
-    disp('      Convert from zero / pole to state space form (zp2ss)')
-    disp('  3)  Convert from state space to transfer function form (ss2tf)')
-    disp('      Convert from transfer function to state space form (tf2ss)')
-    disp('  4)  Convert from transfer function to zero / pole form (tf2zp)')
-    disp('      Convert from zero / pole to transfer function form (zp2tf)')
-    disp('  5)  Return to main demo menu')
-    disp(' ')
+    disp("Octave Model Manipulations Demo")
+    disp("=======================================")
+    disp("  1)  Perform continuous to discrete time conversion (c2d)")
+    disp("  2)  Convert from state space to zero / pole form (ss2zp)")
+    disp("      Convert from zero / pole to state space form (zp2ss)")
+    disp("  3)  Convert from state space to transfer function form (ss2tf)")
+    disp("      Convert from transfer function to state space form (tf2ss)")
+    disp("  4)  Convert from transfer function to zero / pole form (tf2zp)")
+    disp("      Convert from zero / pole to transfer function form (zp2tf)")
+    disp("  5)  Return to main demo menu")
+    disp(" ")
     k=6;
     while(k > 5 || k < 1)
-      k = input('Please enter a number:');
+      k = input("Please enter a number:");
     endwhile
     if (k == 1)
       clc
-      disp('Perform continuous to discrete time conversion (c2d)\n')
-      disp('Example #1, Consider the following continuous time state space system:\n')
+      disp("Perform continuous to discrete time conversion (c2d)\n")
+      disp("Example #1, Consider the following continuous time state space system:\n")
       a=[0, 1; -25, -4]
       b=[0; 1]
       c=[1, 1]
       d=1
       prompt
-      disp('\nTo convert this to a discrete time system (using a zero order hold),')
-      disp('use the following commands:\n')
+      disp("\nTo convert this to a discrete time system (using a zero order hold),")
+      disp("use the following commands:\n")
       cmd="sys=ss2sys(a,b,c,d);";
       run_cmd
       cmd="dsys = c2d(sys,0.2);";
       run_cmd
       cmd="sysout(dsys);";
       run_cmd
-      disp('Function check\n')
-      disp('Check the poles of sys vs dsys:\n')
+      disp("Function check\n")
+      disp("Check the poles of sys vs dsys:\n")
       cmd="[da,db]=sys2ss(dsys);";
       run_cmd
       cmd="lam = eig(a);";
       run_cmd
-      disp('Discretize the continuous time eigenvalues using the matrix exponential:\n')
-      disp('lambc = exp(lam*0.2)\n')
+      disp("Discretize the continuous time eigenvalues using the matrix exponential:\n")
+      disp("lambc = exp(lam*0.2)\n")
       lambc = exp(lam*0.2)
-      disp('Check the eigenvalues of da\n')
+      disp("Check the eigenvalues of da\n")
       lambd = eig(da)
-      disp('Calculate the difference between lambd and lambc:\n')
-      cmd = 'error = sort(lambd)-sort(lambc)\n';
+      disp("Calculate the difference between lambd and lambc:\n")
+      cmd = "error = sort(lambd)-sort(lambc)\n";
       run_cmd
       disp("The error is on the order of roundoff noise, so we're o.k.")
       prompt
       clc
     elseif (k == 2)
       clc
-      disp('Convert from state space to zero / pole form (ss2zp)\n')
-      disp('Example #1, Consider the following state space system:\n')
+      disp("Convert from state space to zero / pole form (ss2zp)\n")
+      disp("Example #1, Consider the following state space system:\n")
       a=[0, 3, 1; -2, -4, 5; 5, 8, 2]
       b=[0; 5; 2.5]
       c=[6, -1.9, 2]
       d=[-20]
       prompt
-      disp(' ')
-      disp('\nTo find the poles and zeros of this sytstem, use the following command:\n')
-      disp('\n[zer, pol] = ss2zp(a, b, c, d)\n')
+      disp(" ")
+      disp("\nTo find the poles and zeros of this sytstem, use the following command:\n")
+      disp("\n[zer, pol] = ss2zp(a, b, c, d)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [zer, pol] = ss2zp(a, b, c, d)
-      disp('Variable Description:\n')
-      disp('zer, pol => zeros and poles of the state space system')
-      disp('a, b, c, d => state space system\n')
+      disp("Variable Description:\n")
+      disp("zer, pol => zeros and poles of the state space system")
+      disp("a, b, c, d => state space system\n")
       prompt
       clc
-      disp('Convert from zero / pole to state space form (zp2ss)\n')
-      disp('Example #1, Consider the following set of zeros and poles:\n')
+      disp("Convert from zero / pole to state space form (zp2ss)\n")
+      disp("Example #1, Consider the following set of zeros and poles:\n")
       zer
       pol
       prompt
-      disp('\nTo find an equivalent state space representation for this set of poles')
-      disp('and zeros, use the following commands:\n')
+      disp("\nTo find an equivalent state space representation for this set of poles")
+      disp("and zeros, use the following commands:\n")
       k=1
-      disp('\n[na, nb, nc, nd] = zp2ss(zer, pol, k)\n')
+      disp("\n[na, nb, nc, nd] = zp2ss(zer, pol, k)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [na, nb, nc, nd] = zp2ss(zer, pol, k)
-      disp('Variable Description:\n')
-      disp('na, nb, nc, nd => state space system equivalent to zero / pole input')
-      disp('zer, pol => zeros and poles of desired state space system')
-      disp('k => gain associated with the zeros\n')
+      disp("Variable Description:\n")
+      disp("na, nb, nc, nd => state space system equivalent to zero / pole input")
+      disp("zer, pol => zeros and poles of desired state space system")
+      disp("k => gain associated with the zeros\n")
       prompt
-      disp('Function check\n')
-      disp('Are the eigenvalues of the origonal state space system the same as the')
-      disp('eigenvalues of the newly constructed state space system ?\n')
-      disp('Find the difference between the two sets of eigenvalues')
-      disp('error = sort(eig(a)) - sort(eig(na))\n')
+      disp("Function check\n")
+      disp("Are the eigenvalues of the origonal state space system the same as the")
+      disp("eigenvalues of the newly constructed state space system ?\n")
+      disp("Find the difference between the two sets of eigenvalues")
+      disp("error = sort(eig(a)) - sort(eig(na))\n")
       error = sort(eig(a)) - sort(eig(na))
       prompt
       clc
     elseif (k == 3)
       clc
-      disp('Convert from state space to transfer function (ss2tf)\n')
-      disp('Example #1, Consider the following state space system:\n')
+      disp("Convert from state space to transfer function (ss2tf)\n")
+      disp("Example #1, Consider the following state space system:\n")
       a=[0, 1; -2, -3]
       b=[1; 1]
       c=[1, 9]
       d=[1]
       prompt
-      disp('\nTo find an equivalent transfer function for this system, use')
-      disp('the following command:\n')
-      disp('[num, den] = ss2tf(a, b, c, d)\n')
+      disp("\nTo find an equivalent transfer function for this system, use")
+      disp("the following command:\n")
+      disp("[num, den] = ss2tf(a, b, c, d)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [num,den] = ss2tf(a, b, c, d)
-      disp('Variable Description:\n')
-      disp('num, den => numerator and denominator of transfer function that is')
-      disp('            equivalent to the state space system')
-      disp('a, b, c, d => state space system\n')
+      disp("Variable Description:\n")
+      disp("num, den => numerator and denominator of transfer function that is")
+      disp("            equivalent to the state space system")
+      disp("a, b, c, d => state space system\n")
       prompt
       clc
-      disp('Convert from transfer function to state space form (tf2ss)\n')
-      disp('Example #1, Consider the following transfer function:\n')
+      disp("Convert from transfer function to state space form (tf2ss)\n")
+      disp("Example #1, Consider the following transfer function:\n")
       num
       den
       prompt
-      disp('\nTo find an equivalent state space representation for this system, use')
-      disp('the following command:\n')
-      disp('[a, b, c, d] = tf2ss(num, den)\n')
+      disp("\nTo find an equivalent state space representation for this system, use")
+      disp("the following command:\n")
+      disp("[a, b, c, d] = tf2ss(num, den)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [a, b, c, d] = tf2ss(num, den)
-      disp('Variable Description:\n')
-      disp('a, b, c, d => state space system equivalent to transfer function input')
-      disp('num, den => numerator and denominator of transfer function that is equivalent')
-      disp('            to the state space system\n')
+      disp("Variable Description:\n")
+      disp("a, b, c, d => state space system equivalent to transfer function input")
+      disp("num, den => numerator and denominator of transfer function that is equivalent")
+      disp("            to the state space system\n")
       prompt
       clc
     elseif (k == 4)
       clc
-      disp('Convert from transfer function to zero / pole form (tf2zp)\n')
-      disp('Example #1, Consider the following transfer function:\n')
+      disp("Convert from transfer function to zero / pole form (tf2zp)\n")
+      disp("Example #1, Consider the following transfer function:\n")
       num=[1, 2, 3, 4, 5, ]
       den=[1, 2, 3, 4, 5, 6, 7]
       prompt
-      disp('\nTo find the zeros and poles of this system, use the following command:\n')
-      disp('[zer,pol] = tf2zp(num,den)\n')
+      disp("\nTo find the zeros and poles of this system, use the following command:\n")
+      disp("[zer,pol] = tf2zp(num,den)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [zer,pol] = tf2zp(num,den)
-      disp('Variable Description:\n')
-      disp('zer,pol => zeros and poles of the transfer function')
-      disp('num, den => numerator and denominator of transfer function\n')
+      disp("Variable Description:\n")
+      disp("zer,pol => zeros and poles of the transfer function")
+      disp("num, den => numerator and denominator of transfer function\n")
       prompt
       clc
-      disp('Convert from zero / pole to transfer function (zp2tf)\n')
-      disp('Example #1, Consider the following set of zeros and poles:\n')
+      disp("Convert from zero / pole to transfer function (zp2tf)\n")
+      disp("Example #1, Consider the following set of zeros and poles:\n")
       zer
       pol 
       prompt
-      disp('\nTo find an equivalent transfer function representation for this set')
-      disp('of poles and zeros, use the following commands:\n')
+      disp("\nTo find an equivalent transfer function representation for this set")
+      disp("of poles and zeros, use the following commands:\n")
       k=1
-      disp('\n[num, den] = zp2tf(zer, pol, k)\n')
+      disp("\n[num, den] = zp2tf(zer, pol, k)\n")
       prompt
-      disp('Results:\n')
+      disp("Results:\n")
       [num, den] = zp2tf(zer, pol, k)
-      disp('Variable Description:\n')
-      disp('[num, den] => transfer function representation of desired set of zeros')
-      disp('              and poles') 
-      disp('a, b, c, d => state space system')
-      disp('zer, pol => zeros and poles of desired state space system')
-      disp('k => gain associated with the zeros\n')
+      disp("Variable Description:\n")
+      disp("[num, den] => transfer function representation of desired set of zeros")
+      disp("              and poles") 
+      disp("a, b, c, d => state space system")
+      disp("zer, pol => zeros and poles of desired state space system")
+      disp("k => gain associated with the zeros\n")
       prompt
       clc
     elseif (k == 5)
--- a/scripts/control/polyout.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/polyout.m	Wed Dec 22 23:36:14 1999 +0000
@@ -44,7 +44,7 @@
   endif
   
   if (nargin == 1)
-    x = 's';
+    x = "s";
   elseif( ! isstr(x) )
     error("polyout: second argument must be a string");
   endif
@@ -57,8 +57,8 @@
     else                 tmp = num2str(c(1));       endif
 
     for ii=2:n
-      if(real(c(ii)) < 0)     ns = ' - ';    c(ii) = -c(ii);
-      else                    ns = ' + ';                      endif
+      if(real(c(ii)) < 0)     ns = " - ";    c(ii) = -c(ii);
+      else                    ns = " + ";                      endif
 
       if( imag(c(ii)) )       nstr = sprintf("(%s)",com2str(c(ii)) );
       else                    nstr = num2str(c(ii));           endif
--- a/scripts/control/sysconnect.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/sysconnect.m	Wed Dec 22 23:36:14 1999 +0000
@@ -127,7 +127,7 @@
   output_list = reshape(output_list,1,length(output_list));
 
   ## make sure we're in state space form
-  sys = sysupdate(sys,'ss');
+  sys = sysupdate (sys, "ss");
 
   ## permute rows and columns of B,C,D matrices into pseudo-dgkf form...
   all_inputs = sysreorder(mm,input_list);
@@ -268,8 +268,10 @@
   endfor
   
   ## maintain original system type if it was SISO
-  if    (strcmp(sysgettype(sys),"tf") )       sysupdate(sys,'tf');
-  elseif(strcmp(sysgettype(sys),"zp") )       sysupdate(sys,'zp');
+  if (strcmp (sysgettype (sys), "tf"))
+    sysupdate (sys, "tf");
+  elseif (strcmp (sysgettype (sys),"zp"))
+    sysupdate (sys, "zp");
   endif
 
 endfunction
--- a/scripts/control/sysrepdemo.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/sysrepdemo.m	Wed Dec 22 23:36:14 1999 +0000
@@ -30,7 +30,7 @@
   save_val = page_screen_output;
   page_screen_output = 1;
 
-  disp('System representation demo:')
+  disp("System representation demo:")
   num = [5, -1];
   denom = [1, -2, 6];
   a = b = c = [];
@@ -43,7 +43,7 @@
   ch_quit = ch_details+1;
   while(syschoice != ch_quit)
    disp(" ")
-    syschoice = menu('Octave System Representation Menu', ...
+    syschoice = menu("Octave System Representation Menu", ...
       "General overview of system representation (DO THIS FIRST)", ...
       "Initialize a system (ss2sys, tf2sys, zp2sys)", ...
       "Extract data from a system(sys2ss, sys2tf, sys2zp, etc.)", ...
@@ -54,11 +54,11 @@
     if(syschoice == 1)  # general overview
       disp("The Octave Control Systems Toolbox (OCST) was designed to")
       disp("provide a simple user interface to a powerful set of tools.")
-      disp(' ')
-      disp('               ----------')
-      disp(' input(s) ---->| System | ---> output(s) ')
-      disp('               ----------')
-      disp(' ')
+      disp(" ")
+      disp("               ----------")
+      disp(" input(s) ---->| System | ---> output(s) ")
+      disp("               ----------")
+      disp(" ")
       disp("Like other computer-aided control system design tools, the OCST")
       disp("enables users to enter their descriptions of dynamic systems in ")
       disp("their preferred form (state space, transfer function, or ");
@@ -101,7 +101,7 @@
       disp("OCST package will be quite easy to use.")
     elseif(syschoice == ch_init) % Initialize
       disp("Initialization of a system:");
-      disp(' ');
+      disp(" ");
       formopt = 0;
       while(formopt != 4)
       disp("Three data formats may be used to initialize a system:")
@@ -111,15 +111,15 @@
 		"zero-pole form         (zp2sys)", ...
 	    	"Return to System representation menu");
         if(formopt == 1)
-          disp('State space representation of a system is based on the usual')
-          disp('multi-variable differential equations')
-          disp(' ')
-          disp('  . ')
-          disp('  x = A x + B u      -or -   x(k+1) = A x(k) + B u(k) ')
-          disp('  y = C x + D u                y(k) = C x(k) + D u(k) ')
-          disp(' ')
-          disp('for matrices A, B, C, D of appropriate dimension.')
-          disp(' ')
+          disp("State space representation of a system is based on the usual")
+          disp("multi-variable differential equations")
+          disp(" ")
+          disp("  . ")
+          disp("  x = A x + B u      -or -   x(k+1) = A x(k) + B u(k) ")
+          disp("  y = C x + D u                y(k) = C x(k) + D u(k) ")
+          disp(" ")
+          disp("for matrices A, B, C, D of appropriate dimension.")
+          disp(" ")
           ssopt = 0;
           ssquit = 5;
           while(ssopt < ssquit)
--- a/scripts/control/tf2sys.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/tf2sys.m	Wed Dec 22 23:36:14 1999 +0000
@@ -59,16 +59,16 @@
 
   ## Test for the correct number of input arguments
   if ((nargin < 2) || (nargin > 5))
-    usage('outsys=tf2sys(num,den[,tsam,inname,outname])');
+    usage ("outsys = tf2sys (num, den [, tsam, inname, outname])");
     return
   endif
 
   ## check input format 
   if( ! ( (is_vector(num) || is_scalar(num)) && ...
 	(is_vector(den) || is_scalar(den))) )
-    error(['num (',num2str(rows(num)),'x',num2str(columns(num)), ...
-      ') and den (',num2str(rows(den)),'x',num2str(columns(den)), ...
-      ') must be vectors'])
+    error(["num (",num2str(rows(num)),"x",num2str(columns(num)), ...
+      ") and den (",num2str(rows(den)),"x",num2str(columns(den)), ...
+      ") must be vectors"])
   endif
   
   ## strip leading zero coefficients
@@ -83,7 +83,7 @@
   if(nargin <= 2)           tsam = 0;		# default
   elseif (isempty(tsam))    tsam = 0;           endif
   if ( (! (is_scalar(tsam) && (imag(tsam) == 0) )) || (tsam < 0) )
-    error('tsam must be a positive real scalar')
+    error("tsam must be a positive real scalar")
   endif
 
   outsys.num = num;
--- a/scripts/control/tfout.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/tfout.m	Wed Dec 22 23:36:14 1999 +0000
@@ -42,7 +42,7 @@
   endif
   
   if (nargin == 2)
-    x = 's';
+    x = "s";
   elseif( ! isstr(x) )
     error("tfout: third argument must be a string");
   endif
@@ -56,7 +56,7 @@
     disp(y)
     disp(denomstring)
   else
-    error('tfout: empty transfer function')
+    error ("tfout: empty transfer function")
   end
 
   empty_list_elements_ok = save_empty;
--- a/scripts/control/tzero.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/tzero.m	Wed Dec 22 23:36:14 1999 +0000
@@ -79,7 +79,7 @@
   ## problem balancing method (Hodel and Tiller, Linear Alg. Appl., 1992)
 
   Asys = zgpbal(Asys); [A,B,C,D] = sys2ss(Asys);   # balance coefficients
-  meps = 2*eps*norm([A, B; C, D],'fro');
+  meps = 2*eps*norm ([A, B; C, D], "fro");
   Asys = zgreduce(Asys,meps);  [A, B, C, D] = sys2ss(Asys); # ENVD algorithm
   if(!isempty(A))
     ## repeat with dual system
--- a/scripts/control/zp2sys.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/zp2sys.m	Wed Dec 22 23:36:14 1999 +0000
@@ -77,7 +77,7 @@
   endif
 
   if (! is_scalar(k))
-     error('k must be a scalar');
+     error("k must be a scalar");
   endif
 
   ## Test proper numbers of poles and zeros.  The number of poles must be 
--- a/scripts/control/zpout.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/control/zpout.m	Wed Dec 22 23:36:14 1999 +0000
@@ -46,7 +46,7 @@
   endif
  
   if (nargin == 3)
-    x = 's';
+    x = "s";
   elseif( ! isstr(x) )
     error("zpout: third argument must be a string");
   endif
@@ -100,7 +100,7 @@
       disp(denomstring)
     endif
   else
-    error('zpout: empty transfer function')
+    error ("zpout: empty transfer function")
   end
 
   empty_list_elements_ok = save_empty;
--- a/scripts/image/loadimage.m	Wed Dec 22 22:11:51 1999 +0000
+++ b/scripts/image/loadimage.m	Wed Dec 22 23:36:14 1999 +0000
@@ -45,7 +45,7 @@
 
   ## The file is assumed to have variables img and map, or X and map.
 
-  eval (['load ', file]);
+  eval (sprintf ("load %s", file));
 
   if (exist ("img"))
     img_retval = img;
--- a/src/ChangeLog	Wed Dec 22 22:11:51 1999 +0000
+++ b/src/ChangeLog	Wed Dec 22 23:36:14 1999 +0000
@@ -1,3 +1,12 @@
+1999-12-22  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* lex.l (Vwarn_single_quote_string): New variable.
+	(syms_of_lex): DEFVAR it.
+	(warn_single_quote_string): New function.
+	(gripe_single_quote_string): New function.
+	Use new stuff to allow warnings for code that uses single quote
+	characters to introduce string constants.
+
 1999-12-20  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
 	* mkbuiltins: Add #undef quad to generated file.
--- a/src/lex.l	Wed Dec 22 22:11:51 1999 +0000
+++ b/src/lex.l	Wed Dec 22 23:36:14 1999 +0000
@@ -165,6 +165,8 @@
 
 static bool Vwarn_separator_insert = false;
 
+static bool Vwarn_single_quote_string = false;
+
 // Forward declarations for functions defined at the bottom of this
 // file.
 
@@ -189,6 +191,7 @@
 static yum_yum eat_whitespace (void);
 static yum_yum eat_continuation (void);
 static void maybe_warn_separator_insert (char sep);
+static void gripe_single_quote_string (void);
 
 %}
 
@@ -1755,6 +1758,10 @@
 
 		  yylval.tok_val = new token (s);
 		  token_stack.push (yylval.tok_val);
+
+		  if (delim == '\'')
+		    gripe_single_quote_string ();
+
 		  return TEXT;
 		}
 	    }
@@ -2217,6 +2224,22 @@
     }
 }
 
+static void
+gripe_single_quote_string (void)
+{
+  string nm = curr_fcn_file_full_name;
+
+  if (Vwarn_single_quote_string)
+    {
+      if (nm.empty ())
+	warning ("single quote delimited string near line %d",
+		 input_line_number);
+      else
+	warning ("single quote delimited string near line %d of file %s",
+		 input_line_number, nm.c_str ());
+    }
+}
+
 static int
 warn_separator_insert (void)
 {
@@ -2226,6 +2249,14 @@
 }
 
 static int
+warn_single_quote_string (void)
+{
+  Vwarn_single_quote_string = check_preference ("warn_single_quote_string");
+
+  return 0;
+}
+
+static int
 whitespace_in_literal_matrix (void)
 {
   int pref = 0;
@@ -2252,6 +2283,10 @@
     "print warning if commas or semicolons that might be inserted\n\
 automatically in literal matrices");
 
+  DEFVAR (warn_single_quote_string, 0.0, warn_single_quote_string,
+    "print warning if a signle quote character is used to introduce a\n\
+ string constant");
+
   DEFVAR (whitespace_in_literal_matrix, "", whitespace_in_literal_matrix,
     "control auto-insertion of commas and semicolons in literal matrices");
 }