Table 1. Correlations between the sources and the average spectra.

		STE Convex	STE Sammon Convex	STE MDS Convex	STE IMA Convex	LTE Convex	LTE Sammon Convex	LTE MDS Convex	LTE IMA Convex
A2 vs. GL	A2	0.988	0.741	0.935	0.994	0.977	0.947	0.997	0.995
	GL	0.979	0.999	1.000	0.999	0.607	0.999	1.000	0.999
A2 vs. ME	A2	0.988	0.931	0.915	0.981	0.990	0.981	0.995	0.986
	ME	0.994	0.999	0.998	1.000	0.872	0.994	0.999	0.993
GL vs. ME	GL	0.972	0.999	1.000	0.999	0.776	0.997	0.998	1.000
	ME	0.994	0.994	0.998	0.999	0.831	0.995	0.996	0.998

Table cells should be read as the correlations between the sources and the average spectra (see figures 3 and 4) of the different tumor types. The results of the best performing method for each classification problem are underlined. The latter is measured as the highest average value between the two correlations. When this highest average value is obtained by more than one method, all their corresponding results are underlined.