Plotting Simple Pendulum in MATLAB: Tutorials & Tips

[tigertan]

I'm really confused at the moment and would quite appreciate some guidance.

I've got little to no background in Matlab and am needing to plot a simple pendulum.

I have found the equation of motion which is q(doubledot) = -(g/l)sin(beta)

I don't know how to go about this?

After declaring the variables:

runtime = 50; %duration of simulation in seconds
g = 9.8;
startingangle = 20; %starting angle in degrees
initialvelocity = 0;
length = 1;


How do I go about this?
Does anyone have any good tutorials to help me out?

I know I need to incorporate some function called ode45..

 

[jedishrfu]

ode45 is the runge-kutta ordinary differential equation solver basically you need to provide a step function that it can then call repeatedly to integrate it and generate a solution.

Here's some info from MATLAB support that may help:

http://www.mathworks.com/help/matlab/ref/ode113.html?BB=1