def test_function_scalar(self):
     assert AtmosphereSigmaFactory._derive(0, 0, 0) == 0
     assert AtmosphereSigmaFactory._derive(3, 0, 0) == 3
     assert AtmosphereSigmaFactory._derive(0, 5, 0) == 0
     assert AtmosphereSigmaFactory._derive(0, 0, 7) == 0
     assert AtmosphereSigmaFactory._derive(3, 5, 0) == -12
     assert AtmosphereSigmaFactory._derive(3, 0, 7) == 3
     assert AtmosphereSigmaFactory._derive(0, 5, 7) == 35
     assert AtmosphereSigmaFactory._derive(3, 5, 7) == 23
 def test_function_array(self):
     ptop = 3
     sigma = np.array([2, 4])
     ps = np.arange(4).reshape(2, 2)
     np.testing.assert_equal(
         AtmosphereSigmaFactory._derive(ptop, sigma, ps),
         [[-3, -5], [1, 3]],
     )