digital signal processing problem

Okay, so I am trying to address a biological problem here. I have asked a variant of this question here, but I was not able to get to solving it.

The question:

Four objects are vibrating constantly with some variable frequency and amplitude. I have the X-Y coordinates of the objects w.r.t time. Now, I want to find if there is any correlation between the objects movements.

Also, if there is any correlation between the movement of an object with itself w.r.t time.

I am not sure what to do, I have absolutely no idea about the mathematics involved, but can try to understand what needs to be done.

Thanks! A

• This question is very low quality. Use "cross-correlation" for object to object. use "auto-correlation" for object with itself. But this question is very low quality. You can search for what is correlation.
– acs
Sep 20, 2015 at 21:52
• For what it's worth, I thought the question was fine. Sep 20, 2015 at 22:35
• i'm more concerned about the quality of answers. i also think the question is okay as it is and that Jim answered it adequately. Sep 21, 2015 at 1:40

Since you have the x/y position for each object it should be fairly straightforward. Call the position of each $p_1(t)$ through $p_4(t)$. Subtract the mean from all of them since it sounds like you only care about their movement, not their position.