Fourier Series Coefficients Ck

I am not at all skilled in Matlab and my teacher just expects us to know how to code. I am asking for a lot of help here. I have a problem with a graph of periodic repition and N=10 (N is the period) with length L=5. The amplitude of the graph is 1. So when 0<=n<L x(n) equals 1, otherwise it is 0. How would I calculate the fourier series coefficeints and plot the absolute value of Ck^2 (when k=0:N-1)?

PLEASE HELP I'M DESPERATE!

[Walter Roberson]

What is Ck in your notation ?

[Matthew Benjamin]

Ck are the Fourier coefficients

Answer 1

[Rick Rosson]

Here is a start:

   N = 10;
   L = 5;

   n = 0:N-1

   x = ...
   C = ...

   figure;
   stem(n,x);

   figure;
   stem(n,abs(C));

For help on Fourier:

   >> doc fft
   >> doc fftshift

Answer 2

[Walter Roberson]

Are you talking about a square wave with duty cycle 1/2 and amplitude 1? Or are you talking about a single square pulse? If you are talking about a single square pulse, it is a difference of step functions.

Are you going for analytic calculation or for numeric calculation?

[Matthew Benjamin]

It has 5 separate pulses. I need a numerical calculation.

[Walter Roberson]

Your description is not compatible with it having 5 pulses. You wrote "when 0<=n<L x(n) equals 1, otherwise it is 0" which describes a single pulse over [0,L) with L=5