def __init__(self):
self.img_rows = 28
self.img_cols = 28
self.img_dim = self.img_rows * self.img_cols
self.latent_dim = 128 # The dimension of the data embedding
optimizer = Adam(learning_rate=0.0002, b1=0.5)
loss_function = SquareLoss
self.encoder = self.build_encoder(optimizer, loss_function)
self.decoder = self.build_decoder(optimizer, loss_function)
self.autoencoder = NeuralNetwork(optimizer=optimizer, loss=loss_function)
self.autoencoder.layers.extend(self.encoder.layers)
self.autoencoder.layers.extend(self.decoder.layers)
print ()
self.autoencoder.summary(name="Variational Autoencoder")
def run_prediction():
od_sample_queue = collections.OrderedDict(sorted(samples_queue.items()))
punctuation_samples = np.array(
FeatureGen.punctuation_marks(od_sample_queue.values()))
backspace_samples = np.array(
FeatureGen.backspace_count(od_sample_queue.values()))
type_pace_samples = np.array(FeatureGen.type_rate(od_sample_queue))
new_data = prepare_data(punctuation_samples, type_pace_samples,
backspace_samples)
nn = NeuralNetwork()
model = nn.load_model(JSON_PATH, WEIGHTS_PATH)
print model.predict_proba(new_data)
""" Method which generates sequence of numbers """
X = np.zeros([nums, 10, 20], dtype=float)
y = np.zeros([nums, 10, 20], dtype=float)
for i in range(nums):
start = np.random.randint(0, 10)
num_seq = np.arange(start, start+10)
X[i] = to_categorical(num_seq, n_col=20)
y[i] = np.roll(X[i], -1, axis=0)
y[:, -1, 1] = 1 # Mark endpoint as 1
return X, y
X, y = gen_multiplication_series(3000)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4)
# Model definition
clf = NeuralNetwork(optimizer=optimizer,
loss=CrossEntropy)
clf.add(RNN(10, activation="tanh", bptt_trunc=5, input_shape=(10, 61)))
clf.add(Activation('softmax'))
clf.summary("Recurrent Neural Network")
# Print a problem instance and the correct solution
tmp_X = np.argmax(X_train[0], axis=1)
tmp_y = np.argmax(y_train[0], axis=1)
print ("Number Series Problem:")
print ("X = [" + " ".join(tmp_X.astype("str")) + "]")
print ("y = [" + " ".join(tmp_y.astype("str")) + "]")
print ()
train_err, _ = clf.fit(X_train, y_train, n_epochs=500, batch_size=512)
# Predict labels of the test data
y = data.target
# Convert to one-hot encoding
y = to_categorical(y.astype("int"))
X_train, X_test, y_train, y_test = train_test_split(X,
y,
test_size=0.4,
seed=1)
# Reshape X to (n_samples, channels, height, width)
X_train = X_train.reshape((-1, 1, 8, 8))
X_test = X_test.reshape((-1, 1, 8, 8))
clf = NeuralNetwork(optimizer=optimizer,
loss=CrossEntropy,
validation_data=(X_test, y_test))
clf.add(
Conv2D(n_filters=16,
filter_shape=(3, 3),
stride=1,
input_shape=(1, 8, 8),
padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
clf.add(BatchNormalization())
clf.add(Conv2D(n_filters=32, filter_shape=(3, 3), stride=1,
padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
def build_decoder(self, optimizer, loss_function):
decoder = NeuralNetwork(optimizer=optimizer, loss=loss_function)
decoder.add(Dense(256, input_shape=(self.latent_dim,)))
decoder.add(Activation('leaky_relu'))
decoder.add(BatchNormalization(momentum=0.8))
decoder.add(Dense(512))
decoder.add(Activation('leaky_relu'))
decoder.add(BatchNormalization(momentum=0.8))
decoder.add(Dense(self.img_dim))
decoder.add(Activation('tanh'))
return decoder
class Autoencoder():
"""An Autoencoder with deep fully-connected neural nets.
Training Data: MNIST Handwritten Digits (28x28 images)
"""
def __init__(self):
self.img_rows = 28
self.img_cols = 28
self.img_dim = self.img_rows * self.img_cols
self.latent_dim = 128 # The dimension of the data embedding
optimizer = Adam(learning_rate=0.0002, b1=0.5)
loss_function = SquareLoss
self.encoder = self.build_encoder(optimizer, loss_function)
self.decoder = self.build_decoder(optimizer, loss_function)
self.autoencoder = NeuralNetwork(optimizer=optimizer, loss=loss_function)
self.autoencoder.layers.extend(self.encoder.layers)
self.autoencoder.layers.extend(self.decoder.layers)
print ()
self.autoencoder.summary(name="Variational Autoencoder")
def build_encoder(self, optimizer, loss_function):
encoder = NeuralNetwork(optimizer=optimizer, loss=loss_function)
encoder.add(Dense(512, input_shape=(self.img_dim,)))
encoder.add(Activation('leaky_relu'))
encoder.add(BatchNormalization(momentum=0.8))
encoder.add(Dense(256))
encoder.add(Activation('leaky_relu'))
encoder.add(BatchNormalization(momentum=0.8))
encoder.add(Dense(self.latent_dim))
return encoder
def build_decoder(self, optimizer, loss_function):
decoder = NeuralNetwork(optimizer=optimizer, loss=loss_function)
decoder.add(Dense(256, input_shape=(self.latent_dim,)))
decoder.add(Activation('leaky_relu'))
decoder.add(BatchNormalization(momentum=0.8))
decoder.add(Dense(512))
decoder.add(Activation('leaky_relu'))
decoder.add(BatchNormalization(momentum=0.8))
decoder.add(Dense(self.img_dim))
decoder.add(Activation('tanh'))
return decoder
def train(self, n_epochs, batch_size=128, save_interval=50):
# mnist = fetch_mldata('MNIST original')
mnist = fetch_openml('mnist_784', version=1, cache=True)
X = mnist.data
y = mnist.target
# Rescale [-1, 1]
X = (X.astype(np.float32) - 127.5) / 127.5
for epoch in range(n_epochs):
# Select a random half batch of images
idx = np.random.randint(0, X.shape[0], batch_size)
imgs = X[idx]
# Train the Autoencoder
loss, _ = self.autoencoder.train_on_batch(imgs, imgs)
# Display the progress
print ("%d [D loss: %f]" % (epoch, loss))
# If at save interval => save generated image samples
if epoch % save_interval == 0:
self.save_imgs(epoch, X)
def save_imgs(self, epoch, X):
r, c = 5, 5 # Grid size
# Select a random half batch of images
idx = np.random.randint(0, X.shape[0], r*c)
imgs = X[idx]
# Generate images and reshape to image shape
gen_imgs = self.autoencoder.predict(imgs).reshape((-1, self.img_rows, self.img_cols))
# Rescale images 0 - 1
gen_imgs = 0.5 * gen_imgs + 0.5
fig, axs = plt.subplots(r, c)
plt.suptitle("Autoencoder")
cnt = 0
for i in range(r):
for j in range(c):
axs[i,j].imshow(gen_imgs[cnt,:,:], cmap='gray')
axs[i,j].axis('off')
cnt += 1
fig.savefig("ae_%d.png" % epoch)
plt.close()