#
# vanderpol_demo.m
#
# Octave demonstration script that uses the vector field
# defined in vanderpol.m
#
# This file was generated by the program VFGEN (Version:2.4.0)
# Generated on 10-Jul-2008 at 15:49
#

# Global vector for the parameters.
global vanderpol_parameters;

# Load the vector field definition and the jacobian.
source "vanderpol.m";


# --- Parameters ---
vanderpol_parameters(1) = 0.2;   # epsilon

# --- Initial conditions ---
x_(1) = 0.01;
x_(2) = 0;

# --- Time values ---
t0_ = 0.0;
t1_ = 10.0;
numpoints = 201;
t_ = linspace(t0_,t1_,numpoints);

# --- Solver error tolerances ---
lsode_options("relative tolerance",1e-6);
lsode_options("absolute tolerance",1e-8);

# --- Call the ODE solver ---
xsol_ = lsode({"vanderpol_vf","vanderpol_jac"},x_,t_);

# --- Plot the solution ---
hold off
plot(t_,xsol_(1:end,1),";x;")
hold on
plot(t_,xsol_(1:end,2),";y;")
grid on
xlabel("t")