Basically you could cumsum the acc+gravity to get velocity, and cumsum the velocity to get position. But this is going to be very crude if you don't have any rotational information since you will have to make an assumption about the direction of gravity. I am assuming the accelerometer unit is bouncing around quite a bit.
You probably don't want to extract values from the raw data since that is losing information. Rather, process all of the data and then smooth/sample the results at a lower frequency.
What are the units of acc? Why are all the values non-negative?
