Two-Phase Incremental Kernel PCA for Learning Massive or Online Datasets

Table 3

Training and testing time (sec) on digit “0” when increasing the number of training samples from 500 to 5000.

		500	1000	1500	2000	3000	4000	5000
r		242	366	453	514	605	670	735
N/r		2.07	2.73	3.31	3.89	4.96	5.97	6.80
training stage	KPCA	1.75 ± 0.055	6.98 ± 0.066	18.72 ± 0.140	35.46 ± 0.185	79.97 ± 0.570	154.65 ± 0.687	255.01 ± 2.083
	TP-IKPCA	1.89 ± 0.019	5.34 ± 0.064	9.86 ± 0.085	14.92 ± 0.078	25.40 ± 0.015	37.46 ± 0.031	50.43 ± 0.411
	ratio	0.93	1.31	1.90	2.38	3.15	4.13	5.06
testing stage	KPCA	0.358 ± 0.022	0.650 ± 0.013	1.131 ± 0.018	1.600 ± 0.026	2.406 ± 0.070	3.657 ± 0.170	5.234 ± 0.293
	TP-IKPCA	0.181 ± 0.012	0.266 ± 0.014	0.323 ± 0.017	0.371 ± 0.016	0.429 ± 0.429	0.465 ± 0.011	0.511 ± 0.010
	ratio	1.98	2.44	4.06	4.31	5.61	8.02	10.24