Fig. 3.

Forecast of the COVID-19 epidemic in Shanghai from 01/20/2020 to 02/28/2020 based on the data of first 10 (early), 20 (middle) and 30 (late) days respectively. The first three panels give the results of (upper) five explicit functions, (middle) four different statistical inference methods combined with the Logistic function (the exponent $\gamma$ derived from $R_0$), (lower) and five ODE models. The one with the smallest RMSE to the training data is drawn. The last row shows the variations of AICc (for training data), RMSE (for test data) and RC for four explicit functions with respect to different sizes of training data set (from Jan. 20th to the date as marked).