The pca_gui main menu

The main menu is shown in Fig. 14. It consists of the following options:

• The File menu is used to load the data in the program.
• The Preprocess menu gives different options to process the data prior to analysis. For example, the stack energy range can be limited, or one can pick a subregion of the stack.
• Components opens a widget used to carry out principal component analysis (PCA).
• Clusters opens a widget used to perform cluster analysis. PCA has to be calculated and the number of significant components chosen for the Cluster button to become sensitive.
• Target spectra/maps button opens a widget used to perform Singular Value Decomposition (SVD) calculation of composition maps based on a set of spectra. For the Target button to become sensitive, one must have at least read in a data file and an $I_{0}$ spectrum.
• Help shows very brief help text.

In addition, the main menu has a Zoom option which zooms all displayed images, and a display of the loaded stack file and file most recently written.

Figure 14: Main menu of pca_gui.