User Defined Preprocessing

Each preprocessing method available in the preprocess function is defined using a preprocessing structure. The standard methods are defined in the preprocatalog file, and additional user-defined methods can be defined in the preprouser file. The methods defined in these two files are available to all functions making use of the preprocess function. See the preprouser file for examples of defining and adding methods to the available methods catalog. The fields in a preprocessing structure include:

• description - textual description of the particular method.
• calibrate - cell containing the line(s) to execute during a calibration operation.
• apply - cell containing the line(s) to execute during an apply operation.
• undo - cell containing the line(s) to execute during an undo operation.
• out - cell used to hold calibration-phase results for use in apply or undo.
• settingsgui - function name to execute when the "Settings" button is pressed in the GUI.
• settingsonadd - Boolean: 1 = automatically bring up settings GUI when method is "added".
• usesdataset - Boolean: indicates if this method should be passed a DataSet Object (1) or a raw matrix (0).
• caloutputs - integer: number of expected items in field out after calibration has been performed.
• keyword - text string which users can pass to preprocess to obtain this structure.
• userdata - user-defined variable often used to store method options.