Loading a Database
The first step is loading a database: a set of classified instances stored on a file:
The file loaded has to be on the form imposed by its format. Otherwise, the loading will cause an error. To know how are these forms, see on examples folder, there are many example files on both formats.
The arff format determines which attributes are numeric or nominal, the txt format doesn't. If an attribute on a txt file has only numeric values and the number of values exceeds the number of states allowed defined on the global options (on main window: Global Options > Preferences...), the attribute is considered numeric, otherwise, nominal.
In case of a sucessfull loading, the Attributes tab is enabled (see below). The class attribute is presented on the left, while the others are on the right. Each attribute is represented as a folder containing its possible values. By default, the class attribute is the last one on the loaded file. The user can change the class attribute through the combo box located on this same screen. The option of learning is enabled too.