Table 5. The performance comparison between all the features and the optimized feature subsets for Beijing and Shanghai’s dataset.

Dataset	All the features		PCA		SBFS
	RMSE	R squared	RMSE	R squared	RMSE	R squared
Beijing	40.43	0.68	39.08	0.69	38.28	0.70
Shanghai	14.05	0.72	13.76	0.76	13.65	0.76