title: Processing Audio Data using Fourier Transforms in Java
body: <p>I'm trying to process audio data. I'm working with Java.
  I've extracted the audio data to an array. Now I should pass N data samples to a function that calculates the Discrete Fourier Transform (or Fast Fourier Transform, which is more efficient). I've read documentation but I'm getting more and more confused. What I'm trying to calculate is the magnitude spectrum (|X(k)|). 
  Can anyone help me? Thanks</p>