i think of acf as a measure of repeating temporal structure and how "strong" and "long" it is, if it exists. that is, it gives you a notion of if and what orde

i think of acf as a measure of repeating temporal structure and how "strong" and "long" it is, if it exists. that is, it gives you a notion of if and what order of an ar model should fit any repeating structure in the data.