BUCHI NIRCal - Manual (Page 199)

Chemometrics
NIRCal 5.5 Manual, Version A 199
3.18.79 Spectra Property Index
Description Each spectra is assigned to exactly that property index with the 1 (one) in the
Original Property matrix.
The property index value is in the range from 0 to the number of properties
minus 1.
Use Use it to select all spectra with the same property (see Tip).
Method Cluster (CLU) / SIMCA / PCR / PLS / MLR
Matrices ID 48
Tip Open it as 2D-plot,

PopUp Menu -> Options -> Show All Values,

Set in PopUp Menu -> Transpose Data.

Set in PopUp Menu -> Option -> Mouse Window Select.

Select with the mouse the number 0.
Then all spectra with the first property are selected. Save this configurated
plot in a workspace i.e. as "Select spectra by property Plot".
Details The following special cases are defined by codes (negative numbers)
-1 : the spectrum is assigned to more than one property
-2 : the spectrum is not assigned to a property (unknown identity)
-3 : the property values of the spectrum seem to be for quantitative use and
not for qualitative (cluster).
Related Topic Original Property
3.18.80 Spectra Radii
Description Each C-Set spectra is covered by a sphere. Its center, the spectra scores
and one radius for all secondary PCs dimensions define the sphere.
Use The spheres define the space where the well known spectra with the defined
property can be.
Method Cluster (CLU) / SIMCA
Matrices ID 50
Tip Good views are:

Graphics -> Scores -> 3D-Scatter

Graphics -> Scores -> Multi 2D-Scatter
The spectra Radii depend on the secondary PCs selection.
Details There are 3 Radii calculation formula and the Radii Blow Up limit can be also
changed by the user.
Related Topic Property Box Radii , Property Box Center
The Radii Blow Up limit and the Radius calculation formula (1 and 2: for Cluster, 3: only for SIMCA)
can be changed under:
Calibration -> Parameter -> Blow Up Limit -> Radii and Radius formula.
All radii can be blowed up by a constant scale. The scale can be in the range from near zero to 1000
(zero makes no sense!).
See:
Cluster (CLU)
NOTE
Changing the calculation formula and blow up parameter can modify the calibration in a dramatic way.
An optimum between robustness and selectivity of the calibration should be found.