Forecasting of Wastewater Discharge and the Energy Consumption in China Based on Grey Model

Table 4

Forecasting values by GM(0,2) and IGM(0,2).

Sequence number	Actual value	GM(0,2) model		IGM(0, 2) model
		Model value	Relative error (%)	Model value	Relative error (%)
2	3.278	3.153	3.8	3.293	0.4
3	3.307	3.331	0.7	3.248	1.7
4	3.390	3.518	3.8	3.476	2.5
5	3.679	3.619	1.6	3.623	1.5