Conventions / terminology, 3 conventions / terminology – BUCHI NIRCal User Manual

Page 273

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Appendix

NIRCal 5.5 Manual, Version A

273

Customize derivatives and smoothing pretreatments
The pretreatment "Savitzky Golay 2nd derivative (15 pt. 2nd order)", as we can see in [1] that the
coefficients for 2nd derivative 15 points are:
91,52,19,-8,-29,-48,-53,-56,-53,-48,-29,-8,19,52,91and the norm scale is: 6188

NOTE
Due to errors in that [1] paper, use this coefficients:
91,52,19,-8,-29,-44,-53,-56,-53,-44,-29,-8,19,52,91

-44 instead of -48
and the norm scale is: 6188

To use this in the Linear Filter pretreatment enter this :
91,52,19,-8,-29,-44,-53,-56,-53,-44,-29,-8,19,52,91,6188
that is in the form
oefficient1, coefficient2, ... , coefficient n , norm scale

In the Calibration Protocol the customized coefficients for Linear Filter pretreatment are listed.
To edit and change the coefficients, simply remove the pretreatment and add Linear Filter again.

References:
[1] A. Savitzky and M.J.E. Golay "Smoothing and differentiation of data by simplified least squares
procedures" Anal. Chem., 36, 1627-1639 (1964)

Working with Selections - "Undo" (Part 6)
Losing a well executed selection by making a mistake is very frustrating. To undo a selection change
open the project journal via main menu Project->Journal->Show. Scroll to the end of the journal by
using the mouse or press Ctrl+End.
All recent changes are logged.
The old overwritten selection can be found and can be copied as text and pasted in the custom edit
mode of the selection.

NOTE
Logging depends on the Logging Filter settings Edit->Options->Journal.

4.3 Conventions / Terminology

NIRCal uses the name conventions for chemometrics terms according to Malinowski. This notation
has been used since the first chemometrics package BCAP for the NIRVis spectrometers. In order to
be consistent and to guarantee a smooth transfer from BCAP to NIRCal this notation has been kept for
NIRCal as well (see NIRCal 4.21 user manual, Appendix 2).

Malinowski
Notation

Martens / Naes Notation

Factors

Loadings / PC's (Principal Components)

Loadings

Scores

Matrices

Matrix Dimensions

NIRCal 4

Spectrum Property

Factor

Factors

Wave-

lengths

Spectra

Properties

NIRCal 5

Spectrum Property Loading

Score

PC's