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import tensorflow as tf | ||
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@tf.function(experimental_relax_shapes=True) | ||
def preprocess_features(features): | ||
# features: | ||
# crossing_angle [-20, 20] | ||
# dip_angle [-60, 60] | ||
# drift_length [35, 290] | ||
# pad_coordinate [40-something, 40-something] | ||
bin_fractions = features[:,-2:] % 1 | ||
features = ( | ||
features[:,:3] - tf.constant([[0., 0., 162.5]]) | ||
) / tf.constant([[20., 60., 127.5]]) | ||
return tf.concat([features, bin_fractions], axis=-1) | ||
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_f = preprocess_features | ||
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def get_generator(activation, kernel_init, num_features, latent_dim): | ||
generator = tf.keras.Sequential([ | ||
tf.keras.layers.Dense(units=32, activation=activation, input_shape=(num_features + latent_dim,)), | ||
tf.keras.layers.Dense(units=64, activation=activation), | ||
tf.keras.layers.Dense(units=64, activation=activation), | ||
tf.keras.layers.Dense(units=64, activation=activation), | ||
tf.keras.layers.Dense(units=8*16, activation=activation), | ||
tf.keras.layers.Reshape((8, 16)), | ||
], name='generator') | ||
return generator | ||
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def get_discriminator(activation, kernel_init, dropout_rate, num_features, num_additional_layers, cramer=False, | ||
features_to_tail=False): | ||
input_img = tf.keras.Input(shape=(8, 16)) | ||
features_input = tf.keras.Input(shape=(num_features,)) | ||
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img = tf.reshape(input_img, (-1, 8, 16, 1)) | ||
if features_to_tail: | ||
features_tiled = tf.tile( | ||
tf.reshape(features_input, (-1, 1, 1, num_features)), | ||
(1, 8, 16, 1) | ||
) | ||
img = tf.concat( | ||
[img, features_tiled], | ||
axis=-1 | ||
) | ||
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discriminator_tail = tf.keras.Sequential([ | ||
tf.keras.layers.Conv2D(filters=16, kernel_size=3, padding='same', activation=activation, kernel_initializer=kernel_init), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
tf.keras.layers.Conv2D(filters=16, kernel_size=3, padding='same', activation=activation, kernel_initializer=kernel_init), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
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tf.keras.layers.MaxPool2D(pool_size=(1, 2)), # 8x8 | ||
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tf.keras.layers.Conv2D(filters=32, kernel_size=3, padding='same', activation=activation, kernel_initializer=kernel_init), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
tf.keras.layers.Conv2D(filters=32, kernel_size=3, padding='same', activation=activation, kernel_initializer=kernel_init), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
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tf.keras.layers.MaxPool2D(), # 4x4 | ||
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tf.keras.layers.Conv2D(filters=64, kernel_size=3, padding='valid', activation=activation, kernel_initializer=kernel_init), # 2x2 | ||
tf.keras.layers.Dropout(dropout_rate), | ||
tf.keras.layers.Conv2D(filters=64, kernel_size=2, padding='valid', activation=activation, kernel_initializer=kernel_init), # 1x1 | ||
tf.keras.layers.Dropout(dropout_rate), | ||
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tf.keras.layers.Reshape((64,)) | ||
], name='discriminator_tail') | ||
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head_input = tf.keras.layers.Concatenate()([features_input, discriminator_tail(img)]) | ||
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head_layers = [ | ||
tf.keras.layers.Dense(units=128, activation=activation, input_shape=(num_features + 64,)), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
] | ||
for _ in range(num_additional_layers): | ||
head_layers += [ | ||
tf.keras.layers.Dense(units=128, activation=activation), | ||
tf.keras.layers.Dropout(dropout_rate), | ||
] | ||
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discriminator_head = tf.keras.Sequential( | ||
head_layers + [tf.keras.layers.Dense(units=1 if not cramer else 256, | ||
activation=None)], | ||
name='discriminator_head' | ||
) | ||
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inputs = [features_input, input_img] | ||
outputs = discriminator_head(head_input) | ||
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discriminator = tf.keras.Model( | ||
inputs=inputs, | ||
outputs=outputs, | ||
name='discriminator' | ||
) | ||
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return discriminator | ||
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def disc_loss(d_real, d_fake): | ||
return tf.reduce_mean(d_fake - d_real) | ||
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def gen_loss(d_real, d_fake): | ||
return tf.reduce_mean(d_real - d_fake) | ||
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def disc_loss_cramer(d_real, d_fake, d_fake_2): | ||
return -tf.reduce_mean( | ||
tf.norm(d_real - d_fake, axis=-1) + | ||
tf.norm(d_fake_2, axis=-1) - | ||
tf.norm(d_fake - d_fake_2, axis=-1) - | ||
tf.norm(d_real, axis=-1) | ||
) | ||
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def gen_loss_cramer(d_real, d_fake, d_fake_2): | ||
return -disc_loss_cramer(d_real, d_fake, d_fake_2) | ||
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class BaselineModel_8x16: | ||
def __init__(self, activation=tf.keras.activations.relu, kernel_init='glorot_uniform', | ||
dropout_rate=0.02, lr=1e-4, latent_dim=32, gp_lambda=10., num_disc_updates=8, | ||
gpdata_lambda=0., num_additional_layers=0, cramer=False, | ||
features_to_tail=True, stochastic_stepping=True): | ||
self.disc_opt = tf.keras.optimizers.RMSprop(lr) | ||
self.gen_opt = tf.keras.optimizers.RMSprop(lr) | ||
self.latent_dim = latent_dim | ||
self.gp_lambda = gp_lambda | ||
self.gpdata_lambda = gpdata_lambda | ||
self.num_disc_updates = num_disc_updates | ||
self.num_features = 5 | ||
self.cramer = cramer | ||
self.stochastic_stepping = stochastic_stepping | ||
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self.generator = get_generator( | ||
activation=activation, kernel_init=kernel_init, latent_dim=latent_dim, num_features=self.num_features | ||
) | ||
self.discriminator = get_discriminator( | ||
activation=activation, kernel_init=kernel_init, dropout_rate=dropout_rate, num_features=self.num_features, | ||
num_additional_layers=num_additional_layers, cramer=cramer, features_to_tail=features_to_tail | ||
) | ||
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self.step_counter = tf.Variable(0, dtype='int32', trainable=False) | ||
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# # compile the models with an arbitrary loss func for serializablility | ||
# self.generator.compile(optimizer=self.gen_opt, | ||
# loss='mean_squared_error') | ||
# self.discriminator.compile(optimizer=self.disc_opt, | ||
# loss='mean_squared_error') | ||
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@tf.function | ||
def make_fake(self, features): | ||
size = tf.shape(features)[0] | ||
latent_input = tf.random.normal(shape=(size, self.latent_dim), dtype='float32') | ||
return self.generator( | ||
tf.concat([_f(features), latent_input], axis=-1) | ||
) | ||
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def gradient_penalty(self, features, real, fake): | ||
alpha = tf.random.uniform(shape=[len(real), 1, 1]) | ||
interpolates = alpha * real + (1 - alpha) * fake | ||
with tf.GradientTape() as t: | ||
t.watch(interpolates) | ||
d_int = self.discriminator([_f(features), interpolates]) | ||
# if self.cramer: | ||
# d_fake = self.discriminator([_f(features), interpolates]) | ||
# d_int = tf.norm(d_int - d_fake, axis=-1) | ||
grads = tf.reshape(t.gradient(d_int, interpolates), [len(real), -1]) | ||
return tf.reduce_mean(tf.maximum(tf.norm(grads, axis=-1) - 1, 0)**2) | ||
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def gradient_penalty_on_data(self, features, real): | ||
with tf.GradientTape() as t: | ||
t.watch(real) | ||
d_real = self.discriminator([_f(features), real]) | ||
# if self.cramer: | ||
# d_real = tf.norm(d_real, axis=-1) | ||
grads = tf.reshape(t.gradient(d_real, real), [len(real), -1]) | ||
return tf.reduce_mean(tf.reduce_sum(grads**2, axis=-1)) | ||
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@tf.function | ||
def calculate_losses(self, feature_batch, target_batch): | ||
fake = self.make_fake(feature_batch) | ||
d_real = self.discriminator([_f(feature_batch), target_batch]) | ||
d_fake = self.discriminator([_f(feature_batch), fake]) | ||
if self.cramer: | ||
fake_2 = self.make_fake(feature_batch) | ||
d_fake_2 = self.discriminator([_f(feature_batch), fake_2]) | ||
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if not self.cramer: | ||
d_loss = disc_loss(d_real, d_fake) | ||
else: | ||
d_loss = disc_loss_cramer(d_real, d_fake, d_fake_2) | ||
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if self.gp_lambda > 0: | ||
d_loss = ( | ||
d_loss + | ||
self.gradient_penalty( | ||
feature_batch, target_batch, fake | ||
) * self.gp_lambda | ||
) | ||
if self.gpdata_lambda > 0: | ||
d_loss = ( | ||
d_loss + | ||
self.gradient_penalty_on_data( | ||
feature_batch, target_batch | ||
) * self.gpdata_lambda | ||
) | ||
if not self.cramer: | ||
g_loss = gen_loss(d_real, d_fake) | ||
else: | ||
g_loss = gen_loss_cramer(d_real, d_fake, d_fake_2) | ||
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return {'disc_loss': d_loss, 'gen_loss': g_loss} | ||
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def disc_step(self, feature_batch, target_batch): | ||
feature_batch = tf.convert_to_tensor(feature_batch) | ||
target_batch = tf.convert_to_tensor(target_batch) | ||
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with tf.GradientTape() as t: | ||
losses = self.calculate_losses(feature_batch, target_batch) | ||
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grads = t.gradient(losses['disc_loss'], self.discriminator.trainable_variables) | ||
self.disc_opt.apply_gradients(zip(grads, self.discriminator.trainable_variables)) | ||
return losses | ||
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def gen_step(self, feature_batch, target_batch): | ||
feature_batch = tf.convert_to_tensor(feature_batch) | ||
target_batch = tf.convert_to_tensor(target_batch) | ||
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with tf.GradientTape() as t: | ||
losses = self.calculate_losses(feature_batch, target_batch) | ||
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grads = t.gradient(losses['gen_loss'], self.generator.trainable_variables) | ||
self.gen_opt.apply_gradients(zip(grads, self.generator.trainable_variables)) | ||
return losses | ||
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@tf.function | ||
def training_step(self, feature_batch, target_batch): | ||
if self.stochastic_stepping: | ||
if tf.random.uniform( | ||
shape=[], dtype='int32', | ||
maxval=self.num_disc_updates + 1 | ||
) == self.num_disc_updates: | ||
result = self.gen_step(feature_batch, target_batch) | ||
else: | ||
result = self.disc_step(feature_batch, target_batch) | ||
else: | ||
if self.step_counter == self.num_disc_updates: | ||
result = self.gen_step(feature_batch, target_batch) | ||
self.step_counter.assign(0) | ||
else: | ||
result = self.disc_step(feature_batch, target_batch) | ||
self.step_counter.assign_add(1) | ||
return result |
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