An Improved Nonlinear Grey Bernoulli Model Combined with Fourier Series

Table 4

Out-of-sample comparisons among five grey forecasting models.

Model	MAPE (%)	Forecasted accuracy (%)	Performance
GM (1, 1)	1.4475	98.5525	Good
Optimized GM (1, 1)	1.4450	98.5520	Good
Original NGBM (1, 1)	0.8074	99.1926	Good
Optimized NGBM (1, 1)	0.8073	99.1925	Good
F-NGBM (1, 1)	0.2499	99.7501	Excellent