There are two panes in the upper half of the Spectra Classifier window. The left one is a container of groups of spectra that have been sent from a Database Manager window. You can fill this pane successively with the spectra you have chosen for classification. Each group of spectra is visually represented as a single line in the left or right pane. The right pane contains the groups of spectra that will actually be classified, if you click the Classify Now button. You can move a group from one pane to another by clicking the Add and Remove button. The two-pane set-up allows you to have spectra available in the left pane, ready for inclusion in future classification runs.

If you select a line (group) in either of the two panes, all corresponding records will be previewed in the grid that displays spectra, structures and additional information. If you double click a line (group) in either of the two panes, the Database Manager window, from which the corresponding spectra originate, will automatically open and these records will be selected.

Note: Spectra Classifier can only hold spectra that are still present in the original Database Manager or Chromatogram Processor windows. In addition, once you have created a group of spectra in Spectra Classifier, you must not move the spectra from the original Database Manager window or clear the component spectra from a chromatogram in Chromatogram Processor. If you violate either of these conditions, the group of spectra concerned will be removed from Spectra Classifier

Spectra Classifier contains five radio buttons for the selection of the transformation that should be applied to the spectra. Due to the long names of transformation techniques, only short code names are displayed. However, if you point the cursor at a code name, the full name will be displayed in a small tool tip box.

You can choose from three classification methods: Principal Component Analysis, Neural Networks, and Fuzzy Clustering. If you choose PCA, you can set the number of principal components that should be calculated. If the Neural Networks is your method of choice, the lattice size can be set in two ways; either the user can assign the x and y size, or the program can set the optimal size automatically (recommended method). Fuzzy Clustering method has no options

Once the data have been prepared you can start the classification. This can be done by clicking the Classify Now button. All groups of spectra listed in the right pane will be classified according to the chosen options (transformation and classification method). After the classification is completed, the results are displayed either in a Spectra Projector window (PCA, Fuzzy Clustering ) or in a Neural Networks window (SOM). It must be stressed again that while a classification is being processed, you can continue working with the program, as Mass Frontier is a multi-threading application.