Table 5.
Fitting and predicting accuracy test results of typical and proposed GM(1,1) models: Eqs. (26) and (27).
| k | Year | True value | Typical GM(1,1) | OB-WMSE-GM(1,1) | ||||
|---|---|---|---|---|---|---|---|---|
| Calculated value | AE | APE (%) | Calculated value | AE | APE (%) | |||
| 1 | 1983 | 7490.000000 | 7490.000000 | 0.000000 | 0.000000 | 7490.000000 | 0.000000 | 0.000000 |
| 2 | 1984 | 7665.000000 | 8079.687665 | 414.687665 | 5.410146 | 8024.650484 | 359.650484 | 4.692113 |
| 3 | 1985 | 7904.000000 | 8400.756448 | 496.756448 | 6.284874 | 8338.904630 | 434.904630 | 5.502336 |
| 4 | 1986 | 8565.000000 | 8734.583789 | 169.583789 | 1.979963 | 8665.465314 | 100.465314 | 1.172975 |
| 5 | 1987 | 9718.000000 | 9081.676685 | 636.323315 | 6.547883 | 9004.814473 | 713.185527 | 7.338810 |
| 6 | 1988 | 10,164.000000 | 9442.562279 | 721.437721 | 7.097970 | 9357.452919 | 806.547081 | 7.935331 |
| 7 | 1989 | 10,528.000000 | 9817.788662 | 710.211338 | 6.745928 | 9723.901075 | 804.098925 | 7.637718 |
| 8 | 1990 | 9783.000000 | 10,207.925705 | 424.925705 | 4.343511 | 10,104.699744 | 321.699744 | 3.288355 |
| 9 | 1991 | 10,250.000000 | 10,613.565925 | 363.565925 | 3.546985 | 10,500.410908 | 250.410908 | 2.443033 |
| 10 | 1992 | 10,815.000000 | 11,035.325384 | 220.325384 | 2.037220 | 10,911.618556 | 96.618556 | 0.893375 |
| 11 | 1993 | 11,290.000000 | 11,473.844623 | 183.844623 | 1.628385 | 11,338.929549 | 48.929549 | 0.433388 |
| 12 | 1994 | 11,000.000000 | 11,929.789640 | 929.789640 | 8.452633 | 11,782.974511 | 782.974511 | 7.117950 |