Week 3 - Solving second order ODEs

clear all

close all

clc

l=1;

m=1;

b=0.05;

g=9.81;

%Solving second order differential equation

theta_0=[0;3];

%Initial displacement=0

%Initial velocity=5m/s

t_taken=linspace(0,20,200);

[t,v]=ode45(@(t,theta)ode_func(t,theta,b,g,l,m),t_taken,theta_0);

plot(t,v(:,1))

hold on

plot(t,v(:,2))

grid on

title('Graph')

xlabel('Time')

ylabel('Angular Displacement')

%To animate the pendulum

ANIME=v(:,1)

ab=1

for i=1:length(ANIME)

ANIME=v(i,1)

x0=0;

y0=0;

x1=1*sind(ANIME);

x2=1*cosd(ANIME);

figure(2);

%Plotting the length of the pendulum

plot([x0 x1],[y0 y1],'color','b','linewidth',3)

hold on

plot([0.2 -0.2],[0 0],'color','k','linewidth',4)

plot(x1,y1,'0','MarkerSize',22,'MarkerFaceColor','r')

axis([-1 1 -1.5 0.1]);

hold off

M(ab)=getframe(gcf);

ab=ab+1

end

%Creating a movie file

movie(M)

videofile=VideoWriter('Pendulum.avi','Uncompressed AVI');

open(videofile);

writevideo(videofile,M);

close(videofile)

The challenge was to write a program that solves the ode that relates to the motion of simple pendulum with damping.While writing the program after completing it I was successful in creating the plot but not the animation.I tried ways to figure out what the issue was but unlikely failed to create the animation.

Therefore attaching the image of the plot that i got.