%second_driver.m
% Solving a second order system   -    using MATLAB and ODE23.
%    By Andy Ruina   (2/2/2000)

tspan=[0 5];
x0= 2; v0=3;
zzero=[2 3]'
[t z] = ode23 ('second_rhs',tspan, zzero);  
plot(  z(:,1), z(:,2)  )
title('Andy Ruina''s second plot')