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% Simple ODE system for damped pendulum, with sinusoidal forcing
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function dx_dt = f4(t,x)
x1 = x(1);	%theta
x2 = x(2);	%theta_dot
global alpha w02 f_input
input = feval(f_input,t);
dx_dt = [x2; -alpha*x2-w02*sin(x1)+input];