Forecast of Freight Volume in Xi’an Based on Gray GM (1, 1) Model and Markov Forecasting Model

Table 4

Xi’an’s predicted freight volume from 2009 to 2013 based on the Gray–Markov model.

Year	Gray predicted value ()	Predicted interval ()	Predicted median ()	State probability	Gray–Markov-modified predicted value ()
2009	2.6050	[2.4189, 2.5467]	2.4828	0.67	2.6106
		[2.5467, 2.6745]	2.6106	0.33
		[2.6745, 2.8023]	2.7384	0
2010	3.0894	[2.9039, 3.0317]	2.9678	0.44	3.0956
		[3.0317, 3.1595]	3.0956	0.56
		[3.1595, 3.2873]	3.2234	0
2011	3.6325	[3.4791, 3.6069]	3.5430	0.30	3.6708
		[3.6069, 3.7347]	3.6708	0.70
		[3.7347, 3.8625]	3.7986	0
2012	4.3272	[4.1611, 4.2889]	4.2250	0.20	4.3528
		[4.2889, 4.4167]	4.3528	0.80
		[4.4167, 4.5445]	4.4806	0
2013	5.1615	[4.9698, 5.0976]	5.0337	0.13	5.1449
		[5.0976, 5.2254]	5.1615	0.87
		[5.2254, 5.3532]	5.2893	0