n
    matrix P.
 
    Available statistics:
 
    'accuracy'    : proportion of correctly classified samples
    'logprob'     : log probability of the correct class
    'correlation' : correlation between input and output matrices
    'contingency' : contingency matrix (rows=true class, columns=predicted class)
    'confusion'   : confusion matrix (rows=true class, columns=predicted class)
    'binomial'    : binomial test gives p value for significant
                    classification; takes uneven class