% script file pendulum.m
%
% solve and plot the inverted pendulum problem defined in InvPend.m
%
% Dependency
%       InvPend.m

global g;
g = 386.09;      % constant g
global L; 
global A;
global w;
L = 10;          % length
A = input('Anplitude A: ');
w = input('Angle speed w: ');

tInit = 0;		% initial t
tFinal = 2.0;		% final t
yInit = zeros(2,1);	% [y(0); (d/dt)y(0)]
yInit(1,1) = input('Initial angle: ');
%
% use default tolerance RelTol = 1e-3 and AbsTol = 1e-6
[t,y] = ode45('InvPend', [tInit tFinal], yInit);
%
% figure		% start a new figure window
plot(t, y(:,1))	        % plot (t,y)
title(sprintf('ODE45 Steps = %5.0f, tol = %5.0e', length(t),tol))