private static double dot(double vector1[], double vector2[]) {

        double product = 0;
        assert vector1.length == vector2.length;
        for (int i = 0; i < vector1.length; i++) {
            product += vector1[i] * vector2[i];
        }
        return product;

    }
private static double dot ( double vector1 [ ] , double vector2 [ ] ) { double product = 0 ; assert vector1 . length == vector2 . length ; for ( int i = 0 ; i < vector1 . length ; i ++ ) { product += vector1 [ i ] * vector2 [ i ] ; } return product ; }
returns the dot product of two vectors

@since 1.8