Apache Commons Math Transform library.

[blind melon]

Does anybody have any experience working with this library? I'm trying to use the Fast Fourier Transform class on an audio sequence, so I can get the frequencies, but I have no idea where to begin... I've successfully loaded an audio file with AudioInputStream, but I really have no idea how to go about using this with the FFT.

What I want to eventually do is compare two songs to see if they're similar, and I know I need to get the FFTs in order to do this, so I was wondering if anyone could help explain what's going on (with the FFT), how I go about doing this, or just pointing me in the way of a tutorial or examples. The Apache Commons Math Transform documentation isn't much of a help to me... I kind of need examples to go off of.

[blind melon]

So I don't know if anyone can help me, but I have a array of doubles that's quite large, but its length needs to be a power of 2... so Java's saying I should pad it, but my question is, what would be the best way to pad an array's length/is it possible?