. Author manuscript; available in PMC: 2020 Jun 24.

Published in final edited form as: Environmetrics. 2018 Sep 25;29(8):e2525. doi: 10.1002/env.2525

Table 2:

Mean R² for the first three pollutant PCs from 100 simulated datasets. The standard errors are all less than 0.04. Simulation scenario 1 has uncorrelated GIS covariates. Simulation scenario 2 has correlated GIS covariates.

	Simulation scenario 1			Simulation scenario 2
	R²			R²
	PC1	PC2	PC3	PC1	PC2	PC3

Traditional PCA GIS PC prediction	0.03	0.01	0.00	0.78	0.62	0.18
Predictive PCA	0.01	0.01	0.01	0.85	0.72	0.05
Predictive PCA GIS PLS prediction	0.42	0.53	0.05	0.87	0.74	0.03
Adaptive predictive PCA	0.61	0.52	0.01	0.84	0.76	0.00