This program calibrates the Ornstein–Uhlenbeck process, a mean reverting AR(1) stochastic process. The parameters are estimated using (1)Least Squares fitting and (2)Maximum Likelihood estimation.-This program calibrates the Ornstein–Uhlenbeck process, a mean reverting AR(1) stochastic process.　The parameters are estimated using (1)Least Squares fitting and (2)Maximum Likelihood estimation.