clear all
close all
clc
%inputs
b = 0.05;
m = 0.1;
g = 9.81;
l = 1;
%initial condition
theta_0 = [0;5];
%time points
t_span = linspace(0,20,500);
%solve ODE
[t, result] = ode45(@(t,theta) ode_func(t, theta, b,g,l,m),t_span, theta_0);
plot(t, result(:,1))
hold on
plot(t, result(:,2))
xlabel('plot')
ylabel('time')
function [dtheta_dt] = ode_func(t,theta,b,g,l,m)
theta1 = theta(1)
theta2 = theta(2)
dtheta1_dt = theta2;
dtheta2_dt = -(b/m)*theta2 - (g/l)*sin(theta1);
dtheta_dt = [dtheta1_dt; dtheta2_dt];
end