Cv c-set press, Cv group index, Cv leverages – BUCHI NIRCal User Manual

Page 172: Cv predicted property, 10 cv c-set press, 11 cv group index, 12 cv leverages, 13 cv predicted property

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NIRCal 5.5 Software Manual

172

NIRCal 5.5 Manual, Version A

3.18.10

CV C-Set PRESS

Description

CV C-Set PRESS is the Predicted Residual Error Sum Square for the
samples in case they are in the C-Set of the calibration.

Use

To estimate the number of PCs. Compare it with C-Set PRESS of the final
calibration.

Method

PCR / PLS

Matrices ID

68

Tip

Optimal number of PC, where CV C-Set PRESS has the minimum value.

Details

Shows the CV C-Set PRESS in function of the number of PCs.

Related Topic

C-Set PRESS

3.18.11

CV Group Index

Description

Before CV the spectra can be grouped: the number indicates, to which group
a spectrum belongs.

Use

To find out, which spectra have e.g. same or similar property values with
Property equal or Property segment selection. Using CV each spectra
belonging to the same group will be at the same calculation step in V-Set.

Method

PCR / PLS

Matrices ID

65

Tip

Can be used for dependency plot or for combined scatter plot.

Details

The group number and the spectra belonging to the groups are listed in the
CV calibration protocol.
Zero as group index means: the spectrum belongs to no any group (unused
spectrum: U-Set).

Related Topic

Cross Validation Grouping

;

Custom assign Group to Spectra

3.18.12

CV Leverages

Description

Mean of the spectra Leverages during Cross Validation of the V-Set spectra
group.

Use

To compare with the “Leverages” of the final calibration with all C-Set spectra
to find possible outliers.

Method

PCR / PLS

Matrices ID

70

Tip

High leverages indicate outliers.

Details

For the calculation the primary PCs are taken.

Related Topic

Leverages

3.18.13

CV Predicted Property

Description

CV Predicted Property is the predicted property value for the sample in case
it is left out of the calibration.

Use

Compare it with the predicted value of the final calibration and with the
original property value.

Method

PCR / PLS

Matrices ID

66

Tip

It should be close to the original property value and to the predicted value of
the final calibration.

Details

The CV predicted property is calculated according the selected secondary
PCs.

Related Topic

Predicted Property

,

CV Property Residuum

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