--- a +++ b/trainers/GMVAE.py @@ -0,0 +1,223 @@ +from collections import defaultdict +from math import inf + +from tensorflow.python.ops.losses.losses_impl import Reduction + +from trainers import trainer_utils +from trainers.AEMODEL import Phase, update_log_dicts, indicate_early_stopping, AEMODEL +from trainers.DLMODEL import * + + +class GMVAE(AEMODEL): + class Config(AEMODEL.Config): + def __init__(self): + super().__init__('GMVAE') + self.dim_c = 6 + self.dim_z = 1 + self.dim_w = 1 + self.c_lambda = 1 + self.restore_lr = 1e-3 + self.restore_steps = 150 + self.tv_lambda = 1.8 + + def __init__(self, sess, config, network=None): + super().__init__(sess, config, network) + self.x = tf.placeholder(tf.float32, [None, self.config.outputHeight, self.config.outputWidth, self.config.numChannels], name='x') + self.tv_lambda = tf.placeholder(tf.float32, shape=()) + + # Additional Parameters + self.dim_c = self.config.dim_c + self.dim_z = self.config.dim_z + self.dim_w = self.config.dim_w + self.c_lambda = self.config.c_lambda + self.restore_lr = self.config.restore_lr + self.restore_steps = self.config.restore_steps + self.tv_lambda_value = self.config.tv_lambda + + self.outputs = self.network(self.x, dropout_rate=self.dropout_rate, dropout=self.dropout, config=self.config) + + self.w_mu = self.outputs['w_mu'] + self.w_log_sigma = self.outputs['w_log_sigma'] + self.z_sampled = self.outputs['z_sampled'] + self.z_mu = self.outputs['z_mu'] + self.z_log_sigma = self.outputs['z_log_sigma'] + self.z_wc_mu = self.outputs['z_wc_mus'] + self.z_wc_log_sigma_inv = self.outputs['z_wc_log_sigma_invs'] + self.xz_mu = self.outputs['xz_mu'] + self.pc = self.outputs['pc'] + self.reconstruction = self.xz_mu + + # Print Stats + self.get_number_of_trainable_params() + # Instantiate Saver + self.saver = tf.train.Saver() + + def train(self, dataset): + # Determine trainable variables + self.variables = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES) + + # Build losses + # 1. the reconstruction loss + self.losses['L1'] = tf.losses.absolute_difference(self.x, self.xz_mu, reduction=Reduction.NONE) + self.losses['L1_sum'] = tf.reduce_sum(self.losses['L1'], axis=[1, 2, 3]) + self.losses['reconstructionLoss'] = self.losses['mean_p_loss'] = mean_p_loss = tf.reduce_mean(self.losses['L1_sum']) + self.losses['L2'] = tf.losses.mean_squared_error(self.x, self.xz_mu, reduction=Reduction.NONE) + self.losses['L2_sum'] = tf.reduce_sum(self.losses['L2']) + + # 2. E_c_w[KL(q(z|x)|| p(z|w, c))] + # calculate KL for each cluster + # KL = 1/2( logvar2 - logvar1 + (var1 + (m1-m2)^2)/var2 - 1 ) here dim_c clusters, then we have batchsize * dim_z * dim_c + # then [batchsize * dim_z* dim_c] * [batchsize * dim_c * 1] = batchsize * dim_z * 1, squeeze it to batchsize * dim_z + self.z_mu = tf.tile(tf.expand_dims(self.z_mu, -1), [1, 1, self.dim_c]) + z_logvar = tf.tile(tf.expand_dims(self.z_log_sigma, -1), [1, 1, self.dim_c]) + d_mu_2 = tf.squared_difference(self.z_mu, self.z_wc_mu) + d_var = (tf.exp(z_logvar) + d_mu_2) * (tf.exp(self.z_wc_log_sigma_inv) + 1e-6) + d_logvar = -1 * (self.z_wc_log_sigma_inv + z_logvar) + kl = (d_var + d_logvar - 1) * 0.5 + con_prior_loss = tf.reduce_sum(tf.squeeze(tf.matmul(kl, tf.expand_dims(self.pc, -1)), -1), 1) + self.losses['conditional_prior_loss'] = mean_con_loss = tf.reduce_mean(con_prior_loss) + + # 3. KL(q(w|x)|| p(w) ~ N(0, I)) + # KL = 1/2 sum( mu^2 + var - logvar -1 ) + w_loss = 0.5 * tf.reduce_sum(tf.square(self.w_mu) + tf.exp(self.w_log_sigma) - self.w_log_sigma - 1, 1) + self.losses['w_prior_loss'] = mean_w_loss = tf.reduce_mean(w_loss) + + # 4. KL(q(c|z)||p(c)) = - sum_k q(k) log p(k)/q(k) , k = dim_c + # let p(k) = 1/K# + + closs1 = tf.reduce_sum(tf.multiply(self.pc, tf.log(self.pc * self.dim_c + 1e-8)), [1]) + c_lambda = tf.cast(tf.fill(tf.shape(closs1), self.c_lambda), dtype=tf.float32) + c_loss = tf.maximum(closs1, c_lambda) + self.losses['c_prior_loss'] = mean_c_loss = tf.reduce_mean(c_loss) + + self.losses['loss'] = mean_p_loss + mean_con_loss + mean_w_loss + mean_c_loss + self.losses['restore'] = self.tv_lambda * tf.image.total_variation(tf.subtract(self.x, self.reconstruction)) + self.losses['grads'] = tf.gradients(self.losses['loss'] + self.losses['restore'], self.x)[0] + + # Set the optimizer + optim = self.create_optimizer(self.losses['loss'], var_list=self.variables, learningrate=self.config.learningrate, + beta1=self.config.beta1, type=self.config.optimizer) + + # initialize all variables + tf.global_variables_initializer().run(session=self.sess) + + best_cost = inf + last_improvement = 0 + last_epoch = self.load_checkpoint() + + # Go go go! + for epoch in range(last_epoch, self.config.numEpochs): + ############ + # TRAINING # + ############ + self.process(dataset, epoch, Phase.TRAIN, optim, visualization_keys=['reconstruction', 'L1', 'L2']) + + # Increment last_epoch counter and save model + last_epoch += 1 + self.save(self.checkpointDir, last_epoch) + + ############## + # VALIDATION # + ############## + val_scalars = self.process(dataset, epoch, Phase.VAL, visualization_keys=['reconstruction', 'L1', 'L2']) + + best_cost, last_improvement, stop = indicate_early_stopping(val_scalars['loss'], best_cost, last_improvement) + if stop: + print('Early stopping was triggered due to no improvement over the last 5 epochs') + break + + if self.tv_lambda_value == -1 and self.restore_steps > 0: + ############## + # Determine lambda # + ############## + print('Determining best lambda') + self.determine_best_lambda(dataset) + + def process(self, dataset, epoch, phase: Phase, optim=None, visualization_keys=None): + scalars = defaultdict(list) + visuals = [] + num_batches = dataset.num_batches(self.config.batchsize, set=phase.value) + for idx in range(0, num_batches): + batch, _, _ = dataset.next_batch(self.config.batchsize, set=phase.value) + + fetches = { + 'reconstruction': self.reconstruction, + **self.losses + } + if phase == Phase.TRAIN: + fetches['optimizer'] = optim + + feed_dict = { + self.x: batch, + self.tv_lambda: self.tv_lambda_value, + self.dropout: phase == Phase.TRAIN, + self.dropout_rate: self.config.dropout_rate + } + + run = self.sess.run(fetches, feed_dict=feed_dict) + + # Print to console + print(f'Epoch ({phase.value}): [{epoch:2d}] [{idx:4d}/{num_batches:4d}] loss: {run["loss"]:.8f}') + update_log_dicts(*trainer_utils.get_summary_dict(batch, run, visualization_keys), scalars, visuals) + + self.log_to_tensorboard(epoch, scalars, visuals, phase) + return scalars + + def reconstruct(self, x, dropout=False): + if x.ndim < 4: + x = np.expand_dims(x, 0) + + if self.restore_steps == 0: + feed_dict = { + self.x: x, + self.tv_lambda: self.tv_lambda_value, + self.dropout: dropout, + self.dropout_rate: self.config.dropout_rate + } + results = self.sess.run({'reconstruction': self.reconstruction}, feed_dict=feed_dict) + else: + restored = x.copy() + for step in range(self.restore_steps): + feed_dict = { + self.x: restored, + self.tv_lambda: self.tv_lambda_value, + self.dropout: dropout, # apply only during MC sampling. + self.dropout_rate: self.config.dropout_rate + } + run = self.sess.run({'grads': self.losses['grads']}, feed_dict=feed_dict) + gradients = run['grads'] + restored -= self.restore_lr * gradients + + results = { + 'reconstruction': restored + } + results['l1err'] = np.sum(np.abs(x - results['reconstruction'])) + results['l2err'] = np.sum(np.sqrt((x - results['reconstruction']) ** 2)) + + return results + + def determine_best_lambda(self, dataset): + lambdas = np.arange(20) / 10.0 + mean_errors = [] + fetches = self.losses + + for tv_lambda in lambdas: + errors = [] + for idx in range(int(dataset.num_batches(self.config.batchsize, set=Phase.VAL.value) * 0.2)): + batch, _, _ = dataset.next_batch(self.config.batchsize, set=Phase.VAL.value) + restored = batch.copy() + for step in range(self.restore_steps): + feed_dict = { + self.x: restored, + self.tv_lambda: tv_lambda, + self.dropout: False, + self.dropout_rate: self.config.dropout_rate + } + run = self.sess.run(fetches, feed_dict=feed_dict) + restored -= self.restore_lr * run['grads'] + errors.append(np.sum(np.abs(batch - restored))) + mean_error = np.mean(errors) + mean_errors.append(mean_error) + print(f'mean_error for lambda {tv_lambda}: {mean_error}') + self.tv_lambda_value = lambdas[mean_errors.index(min(mean_errors))] + print(f'Best lambda: {self.tv_lambda_value}')