def test_connect(self):
n_inputs = 10
n_hidden = 20
x = tf.ones([1, n_inputs])
input_layer = Layer(n_units=n_inputs,activation=x)
id_layer1 = Layer(n_hidden,activation=tf.identity)
id_layer2 = Layer(n_hidden,activation=tf.identity)
nn = NeuralNetwork()
# layer 0
nn.add_layer(input_layer)
# layer 1
nn.add_layer(id_layer1)
# layer 2
nn.add_layer(id_layer2)
self.assertEqual(nn.size(),3)
# connect input to output
self.assertEqual(nn.graph.number_of_edges(),2)
nn.connect_layers(0, 2)
self.assertEqual(nn.graph.number_of_edges(),3)
self.assertIsNot(nn.weights(0,1),nn.weights(0,2))
self.assertIsNot(nn.weights(0,1),nn.weights(1,2))
self.assertIsNot(nn.weights(1,2),nn.weights(0,2))
def test_output(self):
n_inputs = 10
n_hidden = 20
x = tf.placeholder(dtype=tf.float32, shape=[None,n_inputs])
input_layer = Layer(n_units=n_inputs,activation=x)
nn = NeuralNetwork(input_layer)
# add an identity layer
id_layer = Layer(n_hidden, activation=tf.identity)
nn.add_layer(id_layer,biased=True)
wij = nn.weights(0,1)
expected_out = id_layer.activation(tf.add(tf.matmul(x,wij), nn.biases(1)))
init = tf.initialize_all_variables()
with tf.Session() as ss:
ss.run(init)
feed = {x: np.ones((1,n_inputs),dtype=np.float32)}
r1 = ss.run(nn.output(), feed_dict=feed)
r2 = ss.run(expected_out,feed_dict=feed)
self.assertTrue(np.array_equal(r1,r2))
def test_equivalent_networks(self):
"""
Create two equivalent neural networks
nn1 = x -> 1 -> div(x/in) -> w -> sigm -> o
nn2 = x -> w -> sigm -> 0
(with shared weights)
"""
x = tf.ones([1, 4])
input_layer = Layer(n_units=4,activation=x)
weights = tf.ones([4,4])
shared_w = tf.Variable(normalised_weight_init(4,4))
nn1 = NeuralNetwork(input_layer)
l11 = Layer(4, lambda x_in: tf.div(x_in, 4))
l21 = Layer(4, tf.nn.sigmoid)
nn1.add_layer(l11,biased=False,shared_weights=weights)
nn1.add_layer(l21,biased=False,shared_weights=shared_w)
self.assertEqual(nn1.graph.number_of_edges(), 2)
self.assertEqual(nn1.size(),3)
nn2 = NeuralNetwork(Layer(4,x))
l12 = Layer(4, tf.nn.sigmoid)
nn2.add_layer(l12,biased=False,shared_weights=shared_w)
self.assertEqual(nn2.size(),2)
self.assertEqual(nn2.graph.number_of_edges(),1)
init_vars = tf.initialize_all_variables()
with tf.Session() as ss:
ss.run(init_vars)
w1 = ss.run(nn1.weights(1,2))
w2 = ss.run(nn2.weights(0,1))
# shared weights should be the same in both networks
self.assertTrue(np.array_equal(w1,w2))
out_nn1 = ss.run(nn1.output())
out_nn2 = ss.run(nn2.output())
# outputs should be the same since the networks are equivalent
self.assertTrue(np.array_equal(out_nn1,out_nn2))
def test_weights(self):
n_inputs = 10
n_hidden = 20
x = tf.ones([1,n_inputs])
input_layer = Layer(n_units=n_inputs,activation=x)
hidden_layer = Layer(n_units=n_hidden,activation=tf.sigmoid)
nn = NeuralNetwork(input_layer)
nn.add_layer(hidden_layer)
weights_ih = nn.weights(0,1)
self.assertTrue(weights_ih is not None)
init = tf.initialize_all_variables()
with tf.Session() as ss:
ss.run(init)
(c, r) = ss.run(tf.shape(weights_ih))
self.assertEqual(c,n_inputs)
self.assertEqual(r,n_hidden)
