question: protected double computeStdDev ( Instance inst , Matrix k ) throws Exception { double kappa = m_kernel . eval ( - 1 , - 1 , inst ) + m_deltaSquared ; double s = 0 ; int n = m_L . length ; for ( int i = 0 ; i < n ; i ++ ) { double t = 0 ; for ( int j = 0 ; j < n ; j ++ ) { t -= k . get ( j , 0 ) * ( i > j ? m_L [ i ] [ j ] : m_L [ j ] [ i ] ) ; } s += t * k . get ( i , 0 ) ; } double sigma = m_delta ; if ( kappa > s ) { sigma = Math . sqrt ( kappa - s ) ; } return sigma ; }
target:  Computes standard deviation for given instance, without transforming target back into original space.