Table 4. 4-fold cross validation training and testing data division for Beijing, Tianjin and Shijiazhuang.

Sl. No.	Data (training/testing)	Duration	No. of data points (days)
1	Train 1	01.01.2014–30.09.2015	638
	Test1	01.10.2015–30.04.2016	213
2	Train 2	01.08.2014–30.04.2016	639
	Test 2	01.01.2014–31.07.2014	212
3	Train 3	02.03.2015–31.07.2014 *	638
	Test 3	01.08.2014–01.03.2015	213
4	Train 4	30.09.2015–01.03.2015**	639
	Test 4	02.03.2015–29.09.2015	212

* 02.03.2015–31.07.2014 represents data from 2^nd March 2015 to 30^th April 2016 and from 1^st January 2014 to 31^st July 2014.

** 30.09.2015–01.03.2015 represents data from 30^th September 2015 to 30^th April 2016 and from 1^st January 2014 to 1^st March 2015.