@Test
public void testMinus() throws Exception {

    DenseMatrix matA = new DenseMatrix(new double[][]{
        new double[]{1, 3, 5},
        new double[]{2, 4, 6},
    });
    DenseMatrix matB = DenseMatrix.ones(2, 3);
    DenseMatrix matC = matA.minus(matB);
    Assert.assertArrayEquals(matC.getData(), new double[]{0, 1, 2, 3, 4, 5}, TOL);
}