Fig. 3
From: Weighted-indexed semi-Markov model: calibration and application to financial modeling
Autocorrelation function of the simulated WISMC process against the real process. The discretization combinations are: quantile 3-state returns, quantile 3-state index 1-min interval (top-left); GMM 3-state returns, GMM 3-state index 1-sec interval (top-right); quantile 5-state returns, quantile 5-state index 1-min interval (bottom-left); GMM 5-state returns, k-means 5-state index 1-sec interval (bottom-right)