Computes statistics accuracy of NBC and NCC, by analyzing the predictions saved on a temporary file; then,
saves the file the computed indicators and deletes the temporary file.
Initializes data members; than, scans the Arff file, checking the formal correctness
of variable declarations, and the coherence of the data with the declarations; stores the information and the data
loaded from file.
Methods for conversions between Arrays and ArraysList (and vice-versa), and for computing average and
standard deviation of arrays, ignoring missing data (denoted as -9999).