Indirect Estimation of Swelling Pressure of Expansive Soil: GEP versus MEP Modelling

Table 6

Details of parameters settings along with various performance indices for RF, DT, SVM, and GB trees.

RF		DT		SVM		GB-trees
No. of trees	100	Criterion	Least square	Kernel type	Dot	No. of trees and bins	50 and 20
Criterion	Least square	Maximal depth	10	C, epsilon ±	0	Maximal depth	5
Maximal depth	10	Prepruning	Yes	Converg epsilon	0.001	Min. rows	10
Prepruning	No	Min. gain	0.01	L Pos	1	Min. split improv	1.00E-05
Guess subset	Yes	Min. leaf size	2	L neg	1	Learning rate	0.01
RMSE	60.612 ± 7.748	RMSE	74.694 ± 15.963	RMSE	90.382 ± 18.882	RMSE	76.828 ± 14.276
Absolute error	46.538 ± 5.798	Absolute error	57.52 ± 14.549	Absolute error	66.687 ± 11.900	Absolute error	62.154 ± 8.215
Relative error	53.09% ± 10.54%	Relative error	59.21% ± 16.69%	Relative error	65.67% ± 14.82%	Relative error	73.03% ± 18.38%
RRSE	0.650 ± 0.105	RRSE	0.812 ± 0.262	RRSE	0.949 ± 0.046	RRSE	0.809 ± 0.034
Squared error	3721.794 ± 966.481	Squared error	5783.066 ± 2326.161	Squared error	8454.147 ± 3641.390	Squared error	6065.551 ± 2325.052
Correlation	0.774 ± 0.083	Correlation	0.659 ± 0.165	Correlation	0.640 ± 0.104	Correlation	0.758 ± 0.071
R^2	0.604 ± 0.133	R^2	0.456 ± 0.213	R^2	0.419 ± 0.143	R^2	0.578 ± 0.107
Spearman rho	0.689 ± 0.096	Spearman rho	0.539 ± 0.177	Spearman rho	0.614 ± 0.112	Spearman rho	0.688 ± 0.070
Kendall tau	0.529 ± 0.086	Kendall tau	0.405 ± 0.150	Kendall tau	0.458 ± 0.098	Kendall tau	0.520 ± 0.071