Week 3 - Solving second order ODEs

program for ODE 
Inputs
b=0.05;
g=9.81;
l=1;
m=0.1;

% initial condition
theta_0 = [0,5];

% time points
t_span = linspace(0,10,500);

% solve ODE
[t, results] = ode45(@(t,theta) ode_func(t, theta, b,g,l,m),t_span, theta_0);

plot(t,results(:,1))
hold on
plot(t,results(:,2))
ylabel('plot')
xlabel('time')

program for function ode_fun
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

for the animating the program pendulam
i tried my level best but i can't complete
this the program i create 

clear all
close all
clc
ct=1;
for b=0.05;
    g=9.81;
    l=1;
    m=0.1;
    
    % initial condition
    theta_0 = [0,5];

    % time points
    t_span = linspace(0,10,500);
    
   % solve ODE
   [t, results] = ode45(@(t,theta) ode_func(t, theta, b,g,l,m),t_span, theta_0);
 
    %plotting
    figure(ct)
    plot(t,results(:,1))
    hold on
    plot(t,results(:,2))
    pause(0.03)
    M(ct) = getframe(gcf);
    ct = ct+1;
end
 
movie(M)
videofile = VideoWriter('ode.avi','Uncompressed AVI');
open(videofile)
writeVideo(videofile,M)
close(videofile)