I obtained a list of $r^2_{end-to-end}$ from a Monte Carlo simulation of polymer movement.
#r-end-squared
58617.14512069625
55606.1082220041
51244.724846185505
65344.140277928964
63392.17236605068
62101.375689808614
58814.8832777033
60040.00627213609
52019.130880313125
56984.44642212785
... ... ... ...
I want to compute autocorrelation, then fit an exponential decay curve on 2D XY plane, and finally obtain the best fit values (fitx, fity).
What fomula can I use for autocorrelation?