Fourier analysis?

Question

If I have a set of coordinates for a time/intensity graph, how could I extract the Fourier coefficients from it?

Answer 1

Compute the Discrete Fourier transform?

The equations are simple, but solving them directly is painful unless you have a very special case.

There is an algorithm, called the Fast Fourier Transform, which is a lot less work, but you still wouldn't do it by hand.

And there is always the question of what are you looking for? Are you looking at periodic behavior? If so, a simple Discrete Fourier transform makes sense. If not, then you have to get into the question of what sort of windowing you use.

Take a look at:
http://en.wikipedia.org/wiki/Discrete_Fourier_transform