public static function mcc(int $tp, int $tn, int $fp, int $fn) : float
    {
        return ($tp * $tn - $fp * $fn)
            / (sqrt(($tp + $fp) * ($tp + $fn)
            * ($tn + $fp) * ($tn + $fn)) ?: EPSILON);
    }
public static function mcc(int $tp, int $tn, int $fp, int $fn) : float
    {
        return ($tp * $tn - $fp * $fn)
            / (sqrt(($tp + $fp) * ($tp + $fn)
            * ($tn + $fp) * ($tn + $fn)) ?: EPSILON);
    }
public static function mcc ( int $ tp , int $ tn , int $ fp , int $ fn ) : float { return ( $ tp * $ tn - $ fp * $ fn ) / ( sqrt ( ( $ tp + $ fp ) * ( $ tp + $ fn ) * ( $ tn + $ fp ) * ( $ tn + $ fn ) ) ? : EPSILON ) ; }
Compute the class mcc score.

@param int $tp
@param int $tn
@param int $fp
@param int $fn
@return float
Compute the class mcc score .