ADDED   mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_rep.txt
Index: mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_rep.txt
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_rep.txt
@@ -0,0 +1,33 @@
+## -*-octave-*- Put Emacs into octave-mode
+## Outline report file for system NonlinearMSD (NonlinearMSD_rep.txt)
+## Generated by MTT on" Thu Mar  7 14:44:37 GMT 2002.
+
+###############################################################
+## Version control history
+###############################################################
+## $Id$
+## $Log$
+## Revision 1.1  2000/12/28 11:58:07  peterg
+## Put under RCS
+##
+###############################################################
+
+mtt NonlinearMSD abg tex			# The system description
+mtt NonlinearMSD sympar tex	        # The system parameters
+## Uncomment the following lines or add others
+## mtt NonlinearMSD dae tex	        # The system dae
+mtt NonlinearMSD ode tex	        # The system ode 
+mtt NonlinearMSD sspar tex		# Steady-state parameters
+mtt NonlinearMSD ss tex 		# Steady state
+## mtt NonlinearMSD dm tex		# Descriptor matrices (of linearised system)
+mtt NonlinearMSD sm tex		# State matrices (of linearised system)
+## mtt NonlinearMSD tf tex		# Transfer function (of linearised system)
+## mtt NonlinearMSD lmfr ps		# log modulus of frequency response (of linearised system)
+## mtt NonlinearMSD simpar tex		# Simulation parameters
+mtt NonlinearMSD numpar tex		# Numerical simulation parameters
+mtt NonlinearMSD state tex		# Simulation initial state
+mtt NonlinearMSD input tex		# Simulation input
+## mtt NonlinearMSD logic tex		# Logic control
+mtt NonlinearMSD odeso ps		# Simulation output
+
+## mtt NonlinearMSD rep txt		# This file

ADDED   mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_sspar.r
Index: mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_sspar.r
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_sspar.r
@@ -0,0 +1,25 @@
+% Steady-state parameter file (NonlinearMSD_sspar.r)
+% Generated by MTT at Thu Mar  7 10:39:15 GMT 2002
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% % Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% % $Id$
+% % $Log$
+% % Revision 1.1  2000/12/28 09:32:04  peterg
+% % Initial revision
+% %
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+%% This one corresponds to the unstretched spring at theta = pi/3 
+%% Note that U is calculated to give equilibrium for all angles
+
+alpha := pi/3;
+
+% Steady-state states
+MTTX1 := 	eta;     %Initial angle (corresponds to u=0)
+MTTX2 := 	0;        %Initial anglular velocity
+% Steady-state inputs
+MTTU1 := 	k*(l^2)*cos(MTTX1/2)*2*(sin(MTTX1/2)-sin(alpha/2));
+;;END;

ADDED   mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_state.txt
Index: mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_state.txt
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/NonlinearMSD_state.txt
@@ -0,0 +1,11 @@
+## -*-octave-*- Put Emacs into octave-mode ##
+ 
+## 
+## System NonlinearMSD, representation state, language txt; 
+## File NonlinearMSD_state.txt; 
+## Generated by MTT on Thu Mar  7 10:50:45 GMT 2002; 
+
+
+
+NonlinearMSD_j	= 0.0;  % Initial angular momentum
+NonlinearMSD_k	= eta; % Initial angle

ADDED   mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/plot_k.m
Index: mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/plot_k.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/examples/Mechanical/Mechanical-1D/NonlinearMSD/plot_k.m
@@ -0,0 +1,18 @@
+## Plots the effective spring constant.
+
+p = NonlinearMSD_numpar;	# Numerical parameters
+s = NonlinearMSD_sympar		# Symbolic parameters
+
+Eta = eta=[0:0.01:1]*pi; K = [];
+for eta=Eta
+  p(s.eta) = eta;		# Change the eta parameter
+  A = NonlinearMSD_sm(p);	# SS A matrix
+  k = -A(2,1);
+  K = [K k];
+endfor
+
+grid;
+ylabel("k");
+xlabel("eta");
+plot(Eta,K);
+figfig("k","eps");