public static int min(int a, int b, int c) {
        return Math.min(Math.min(a, b), c);
    }
@Test
    public void testMin_doubleArr() {
        System.out.println("min");
        double[] x = {-2.1968219, -0.9559913, -0.0431738, 1.0567679, 0.3853515};
        assertEquals(-2.196822, MathEx.min(x), 1E-7);
    }