public static void unitize2(double[] array) {
        double n = norm(array);

        for (int i = 0; i < array.length; i++) {
            array[i] /= n;
        }
    }
@Test
    public void testUnitize2() {
        System.out.println("unitize2");
        double[] data = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0};
        MathEx.unitize2(data);
        assertEquals(1, MathEx.norm2(data), 1E-7);
    }