def test_update_weights(self):
layer = Layer(np.array([1, 1, 2]))
w0 = layer.w
acc_error, lr = np.array([0.5, 0.5, 0.5]), 5
layer.solve_bwd(acc_error, lr)
layer.update_weights()
self.assertTrue((layer.w == (w0 + layer.delta_w)).all())
def test_solve_bwd_requires_one_arg(self):
layer = Layer(np.array([1, 1, 2]))
regex = 'missing 1 required positional argument: \'acc_error\''
with self.assertRaisesRegex(TypeError, regex):
layer.solve_bwd()
def test_delta_w_matches_neuron_dimension(self):
layer = Layer(np.array([1, 1, 2]))
layer.solve_bwd(np.zeros(3))
self.assertEqual(len(layer.delta_w), layer.dim)
def test_error_passed_back_matches_neuron_dimension(self):
layer = Layer(np.array([1, 1, 2]))
layer.solve_bwd(np.zeros(3))
self.assertEqual(len(layer.e), layer.dim)
def test_delta_w_value(self):
layer = Layer(np.array([1, 1, 2]))
acc_error, lr = np.array([0.5, 0.5, 0.5]), 5
layer.solve_bwd(acc_error, lr)
expected = -lr * acc_error * layer.partial_s * layer.x
self.assertTrue((layer.delta_w == expected).all())
def test_error_passed_back_meets_chain_rule(self):
layer = Layer(np.array([1, 1, 2]))
acc_error = np.array([0.5, 0.5, 0.5])
layer.solve_bwd(acc_error, 5)
chain_rule = acc_error * layer.partial_s * layer.w
self.assertTrue((layer.e == chain_rule).all())
def test_partial_s_dimension_matches_neuron_qty(self):
layer = Layer(np.array([1, 1, 2]))
layer.solve_bwd(np.zeros(3), 5)
self.assertEqual(len(layer.partial_s), layer.dim)
def test_partial_s_is_the_derivative_of_sigmoid_function(self):
layer = Layer(np.array([1, 1, 2]))
part_s = layer.s * (1 - layer.s)
layer.solve_bwd(np.zeros(3), 5)
self.assertTrue((part_s == layer.partial_s).all())
def test_solve_bwd_acc_error_matches_dimension(self):
layer = Layer(np.array([1, 1, 2]))
regex = 'The accumulated error dimension doesn\'t match!'
with self.assertRaisesRegex(ValueError, regex):
layer.solve_bwd(np.zeros(5))
def test_solve_bwd_acc_error_should_be_np_array(self):
layer = Layer(np.array([1, 1, 2]))
regex = 'The accumulated error should be a numpy array'
with self.assertRaisesRegex(TypeError, regex):
layer.solve_bwd('void')