def test_get_error_deriv():
lay = Layer(1, 1)
lay.output = np.zeros((1, 1))
target = np.ones((1, 1))
expected_deriv = -target
actual_deriv = lay.get_error_deriv(target)
np.testing.assert_array_equal(expected_deriv, actual_deriv)
target = target * 0
expected_deriv = target
actual_deriv = lay.get_error_deriv(target)
np.testing.assert_array_equal(expected_deriv, actual_deriv)
lay = Layer(2, 2)
lay.output = np.zeros((2, 2))
target = np.array([[1, 2], [3, 4]])
expected_deriv = np.array([[-1, -2], [-3, -4]])
actual_deriv = lay.get_error_deriv(target)
np.testing.assert_array_equal(expected_deriv, actual_deriv)
