. 2015 Apr 20;3:50. doi: 10.3389/fbioe.2015.00050

Table 2.

Comparison of partial least squares models using vibrational spectroscopy and pyrolysis-molecular beam mass spectrometry [reprinted from Lupoi et al. (2014a)].

Method	SEL validation^a^,^g	SEP^b^,^g	RMSEP^c^,^g	r-Val^d	R² Val^e	Outliers^f
Raman 2nd deriv. (19pt) + SNV 32 scans	0.05	0.14	0.13	0.89 ± 0.04	0.79 ± 0.08	1
Raman 1st deriv. (7pt) + EMSC 32 scans	0.05	0.13	0.13	0.91 ± 0.02	0.83 ± 0.04	1
Raman EMSC + 2nd deriv. (15pt) 96 scans	0.05	0.14	0.15	0.90 ± 0.02	0.81 ± 0.04	0
Raman 2nd deriv. (15pt) + SNV 96 scans	0.06	0.17	0.16	0.86 ± 0.02	0.74 ± 0.04	0
MIR EMSC + 2nd deriv. (15pt)	0.05	0.14	0.13	0.87 ± 0.06	0.8 ± 0.1	1
MIR 2nd deriv. (17pt) + MSC	0.05	0.14	0.14	0.91 ± 0.01	0.83 ± 0.01	1
MIR 2nd deriv. (17pt) + SNV	0.05	0.15	0.15	0.87 ± 0.02	0.76 ± 0.03	1
NIR EMSC + 2nd deriv. (25pt)	0.06	0.19	0.20	0.79 ± 0.01	0.62 ± 0.01	0
NIR 2nd deriv. (25pt) + MSC	0.06	0.18	0.18	0.82 ± 0.04	0.67 ± 0.07	1
NIR 2nd deriv. (25pt) + SNV	0.06	0.22	0.21	0.80 ± 0.04	0.65 ± 0.07	1

^aStandard error of the laboratory for the validation data.

^bStandard error of prediction.

^cRoot mean standard error prediction.

^dCorrelation coefficient for the validation set.

^ePearson coefficient of determination for validation.

^fNumber of outliers removed from validation models.

^gAverage errors of three randomly generated models using data provided. Models were not statistically different.

The numbers listed parenthetically reflect the degree of Savitzky–Golay spectral smoothing.

Statistical values are the average of three independent models.