--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/control/base/analdemo.m	Fri Jan 14 04:12:41 2000 +0000
@@ -0,0 +1,243 @@
+## Copyright (C) 1996 Auburn University.  All rights reserved.
+##
+## 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, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} analdemo ()
+## Octave Controls toolbox demo: State Space analysis demo
+## @end deftypefn
+
+## Author: David Clem
+## Created: August 15, 1994
+## Updated by John Ingram December 1996
+
+function analdemo ()
+
+  while (1)
+    clc
+    k=0;
+    while(k > 8 || k < 1)
+      k = menu("Octave State Space Analysis Demo", ...
+        "System grammians (gram, dgram)", ...
+        "System zeros (tzero)", ...
+        "Continuous => Discrete and Discrete => Continuous conversions (c2d,d2c)", ...
+        "Algebraic Riccati Equation (are, dare)", ...
+        "Balanced realizations (balreal, dbalreal)", ...
+        "Open loop truncations via Hankel singular values (balreal, dbalreal)", ...
+        "SISO pole placement", ...
+        "Return to main demo menu");
+    endwhile
+    if (k == 1)
+      clc
+      help dgram
+      prompt
+
+      clc
+      disp("System Grammians: (see Moore, IEEE T-AC, 1981) \n");
+      disp("Example #1, consider the discrete time state space system:\n");
+      a=[1, 5, -8.4; 1.2, -3, 5; 1, 7, 9]
+      b=[1, 5; 2, 6; -4.4, 5]
+      c=[1, -1.5, 2; 6, -9.8, 1]
+      d=0
+      prompt
+      disp("\nThe discrete controllability grammian is computed as follows:");
+      cmd = "grammian = dgram(a, b);";
+      run_cmd;
+      disp("Results:\n");
+      grammian = dgram(a,b)
+      disp("Variable Description:\n");
+      disp("grammian => discrete controllability grammian");
+      disp("a, b => a and b matrices of discrete time system\n");
+      disp("A dual approach may be used to compute the observability grammian.");
+      prompt
+      clc
+
+      help gram
+      prompt
+      clc
+
+      disp("Example #2, consider the continuous state space system:\n");
+      a=[1, 3, -10.2; 3.7, -2, 9; n1, 3, 7]
+      b=[1, 12; 6, 2; -3.8, 7]
+      c=[1, -1.1, 7; 3, -9.8, 2]
+      d=0
+      prompt
+      disp("\nThe continuous controllability grammian is computed as follows:");
+      cmd = "grammian = gram(a, b);";
+      run_cmd;
+      disp("Results:\n");
+      grammian = gram(a,b)
+      disp("Variable Description:\n");
+      disp("grammian => continuous controllability grammian");
+      disp("a, b => a and b matrices of continuous time system\n");
+      disp("A dual approach may be used to compute the observability grammian.");
+      prompt
+      clc
+
+
+    elseif (k == 2)
+      clc
+      help tzero
+      prompt
+
+      disp("System zeros (tzero) example\n");
+      disp("Example #1, consider the state space system:\n");
+      a=[0, 1, 0; -10, -2, 0; -10, 0, -8]
+      b=[0; 1; 9]
+      c=[-10, 0, -4]
+      d=1
+      prompt
+      disp("\nTo compute the zeros of this system, enter the following command:\n");
+      cmd = "zer = tzero(a,b,c,d);";
+      run_cmd;
+      disp("Results:\n");
+      zer = tzero(a,b,c,d)
+      disp("Variable Description:\n");
+      disp("zer => zeros of state space system");
+      disp("a, b, c, d => state space system used as input argument");
+      prompt
+      clc
+
+      disp("Example #2, consider the state space system from example 1 again:");
+      cmd = "sys = ss2sys(a,b,c,d);";
+      disp(cmd);
+      eval(cmd);
+      sysout(sys);
+      disp("\nThe zeros of this system can also be calculated directly from the");
+      disp("system variable:");
+      cmd = "zer = tzero(sys);";
+      run_cmd;
+      disp("Results:\n")
+      zer = tzero(sys)
+      disp("Variable Description:\n");
+      disp("zer => zeros of state space system");
+      disp("sys => state space system used as input argument");
+      prompt
+      clc
+
+    elseif (k == 3)
+      clc
+      help c2d
+      prompt
+
+      clc
+      disp("Continuous => Discrete and Discrete => Continuous conversions (c2d,d2c)");
+      disp("\nExample #1, consider the following continuous state space system");
+      cmd = "sys_cont = ss2sys([-11, 6; -15, 8], [1; 2], [2, -1], 0);";
+      eval(cmd);
+      disp(cmd);
+      disp("Examine the poles and zeros of the continuous system:");
+      sysout(sys_cont,"all");
+      disp("\nTo convert this to a discrete system, a sampling time is needed:");
+      cmd = "Tsam = 0.5;";
+      run_cmd;
+      disp("\nNow convert to a discrete system with the command:");
+      cmd = "sys_disc = c2d(sys_cont,Tsam);";
+      run_cmd;
+      disp("Examine the poles and zeros of the discrete system:");
+      sysout(sys_disc,"all");
+      prompt
+      clc
+
+      disp("\nNow we will convert the discrete system back to a continuous system");
+      disp("using the d2c command:");
+      help d2c
+      prompt
+      cmd = "new_sys_cont = d2c(sys_disc);";
+      run_cmd;
+      disp("\nExamine the poles and zeros of the discrete system:");
+      sysout(new_sys_cont,"all");
+      prompt
+
+    elseif (k == 4)
+      clc
+      help are
+      prompt
+      clc
+
+      disp("Algebraic Riccati Equation (are, dare)");
+
+      disp("\nExample #1, consider the continuous state space system:\n");
+      a=[1, 3, -10.2; 3.7, -2, 9; 1, 3, 7]
+      b=[1, 12; 6, 2; -3.8, 7]
+      c=[1, -1.1, 7; 3, -9.8, 2]
+      d=0
+      prompt
+      disp("\nThe solution to the continuous algebraic riccati equation");
+      disp("is computed as follows:");
+      cmd = "x_cont = are(a, b, c);";
+      run_cmd;
+      disp("Results:\n")
+      x_cont = are(a,b,c)
+      disp("Variable Description:\n")
+      disp("x_cont => solution to the continuous algebraic riccati equation");
+      disp("a, b, c => a, b, and c matrices of continuous time system\n");
+      prompt
+
+      clc
+      help dare
+      prompt
+      clc
+
+      disp("Example #2, consider the discrete time state space system:\n");
+      a=[1, 5, -8.4; 1.2, -3, 5; 1, 7, 9]
+      b=[1, 5; 2, 6; -4.4, 5]
+      c=[1, -1.5, 2; 6, -9.8, 1]
+      d=0
+      r=eye(columns(b))
+      prompt
+      disp("\nThe solution to the continuous algebraic riccati equation");
+      disp("is computed as follows:");
+      cmd = "x_disc = dare(a, b, c, r);";
+      run_cmd;
+      disp("Results:\n")
+      x_disc = dare(a,b,c,r)
+      disp("Variable Description:\n");
+      disp("x_disc => solution to the discrete algebraic riccati equation");
+      disp("a, b, c => a, b and c matrices of discrete time system\n");
+      prompt
+      clc
+
+    elseif (k == 5)
+      disp("--- Balanced realization: not yet implemented")
+    elseif (k == 6)
+      disp("--- Open loop balanced truncation: not yet implemented")
+    elseif (k == 7)
+      disp("SISO pole placement example:")
+      cmd = "sys=tf2sys(1, [1, -2, 1]);";
+      run_cmd
+      disp("System in zero-pole form is:")
+      cmd = "sysout(sys,\"zp\");";
+      run_cmd
+      disp("and in state space form:")
+      cmd = "sysout(sys,\"ss\");";
+      run_cmd
+      disp("Desired poles at -1, -1");
+      cmd = "K=place(sys, [-1, -1])";
+      run_cmd
+      disp("Check results:")
+      cmd = "[A,B] = sys2ss(sys);";
+      run_cmd
+      cmd = "poles=eig(A-B*K)";
+      run_cmd
+      prompt
+    elseif (k == 8)
+      return
+    endif
+  endwhile
+endfunction
+