Hi guys so I have a device which obtains velocity based values over a period of 1 minute (average). I also have another one which I am comparing the different device too, to see if they are similar. Now the velocity values can be quite random, but of both devices they should be similar in terms of increase between each minute, decrease between them, etc; Essentially they should have the same flow.

I saw online that some research has utilized the Pearson correlation to compare these values, but what I'm wondering is why? I read that this correlation only works for linear based values, and from what I read up, the velocities themselves where quite random (although similar in terms of devices). Or at least I don't think there linear.

I was wondering if someone was able to help me out on this?

(cross posted from: http://math.stackexchange.com/questions/1018355/pearson-correlation-of-acclerometer-values)