Metrohm Vision Manual - Manual (Page 105)

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2. Open the combo box and double click the library name for which you want to create the
method.
Define the clustering parameters
1. From the menu select Clustering/Apply Math.
2. Define the appropriate parameters in the Edit Library Clustering Method dialog box:
• Principal Component Cumulative Variance is expressed in percent. A minimum
number of principal components that describe this fraction of variance in the whole
library (and in sub-clusters) will be used for calculations.
• Variation Radius Scale (expressed in units of standard deviation) is defined as the
sphere drawn around each product. If product spheres overlap, the products cannot
reside in different clusters.
• Maximum Leaf Cluster Size defines the size of the lowest level cluster.
• Important: Check Setup Identify Method to create a uniform identification method
for all leaf clusters. This method can be changed later, after examining the results of
clustering.
• Define the appropriate math pretreatment and the wavelength range. You can select
multiple pre-treatments in any order. Click on OK.
3. In the Edit Math Properties dialog box choose the wavelength regions and configure the math
pre-treatments.