public float[] colMeans() {
        float[] x = colSums();

        for (int j = 0; j < n; j++) {
            x[j] /= m;
        }

        return x;
    }
@Test
    public void testColMeans() {
        System.out.println("colMeans");
        float[][] A = {
                { 0.7220180f,  0.07121225f, 0.6881997f},
                {-0.2648886f, -0.89044952f, 0.3700456f},
                {-0.6391588f,  0.44947578f, 0.6240573f}
        };
        float[] r = {-0.06067647f, -0.12325383f, 0.56076753f};

        float[] result = Matrix.of(A).colMeans();
        for (int i = 0; i < r.length; i++) {
            assertEquals(result[i], r[i], 1E-7f);
        }
    }