TABLE 4.

Average mean absolute percentage errors (MAPEs) of the forecasts of the epidemic evolution in the USA, obtained with the proposed algorithm, and with the SIR-fit and GSEIR-fit curve-fitting approaches, for different forecast horizons, that is, 3, 7, and 14 days. The uppermost table reports the average MAPEs computed over the interval from March 10 to July 17; the lowermost table reports the average MAPEs computed over the interval from April 1 to July 17.

Algorithm	3 Days (%)	7 Days (%)	14 Days (%)
Proposed	7.3	11.9	29.8
SIR-fit	81.6	122.4	232.4
GSEIR-fit	14.0	20.0	35.2
Average over the interval from March 10 to July 17
Algorithm	3 Days (%)	7 Days (%)	14 Days (%)
Proposed	3.4	4.5	7.2
SIR-fit	91.4	138.8	267.6
GSEIR-fit	12.1	17.0	28.7
Average over the interval from April 1 to July 17