Table 2.
Values of the adjusted parameters as obtained from the least square data fitting of the worldwide total number of Covid-19 cases to a six logistic modeling. The parameter Ki represents the total number of cases in million units, whereas tci refers to the center position of phase i in number of days since January 22, 2020, τi denotes the time constant, in days, of phase i, and Δti the time duration of phase i. It is also included in this table the average error of the parameters evaluations as well as the calendar days corresponding to the center positions of each phase.
| Parameters | Phase 1 | Phase 2 | Phase 3 | Phase 4 | Phase 5 | Phase 6 |
|---|---|---|---|---|---|---|
| Ki (cases) | 2447 | 32,031 | 35,764 | 44,993 | 59,268 | 70,748 |
| t ci (day) calendar day | 89.631 Apr 19, 2020 | 197.008 Aug 05, 2020 | 298.102 Nov 14, 2020 | 354.909 Jan 10, 2021 | 457.366 Apr 22, 2021 | 575.470 Aug 18, 2021 |
| τi (days) | 10.140 | 32.525 | 21.323 | 21.482 | 19.337 | 26.693 |
| τi − 1 (day−1) | 0.099 | 0.031 | 0.047 | 0.047 | 0.052 | 0.037 |
| Δti (days) | 44.515 | 142.785 | 93.608 | 95.886 | 84.889 | 117.682 |
| Statistics | Number of records | Degrees of freedom | Reduced Chi-Sqr | Residual Sum of Squares | R2 (COD) | Average parameter error (%) |
| 565 | 547 | 0.034 | 18.630 | 0.99999 | 3.85 | |
| Parameter | Value | |||||
| < Ki> | 6.4% | |||||
| <tci> | 0.5% | |||||
| <τι> | 4.7% |