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Get a policy network.
def get_policy(observations, hparams, action_space): """Get a policy network. Args: observations: observations hparams: parameters action_space: action space Returns: Tuple (action logits, value). """ if not isinstance(action_space, gym.spaces.Discrete): raise ValueError("Expecting discr...
Base set of hparams for model - free PPO.
def rlmf_tictactoe(): """Base set of hparams for model-free PPO.""" hparams = rlmf_original() hparams.game = "tictactoe" hparams.rl_env_name = "T2TEnv-TicTacToeEnv-v0" # Since we don't have any no-op actions, otherwise we have to have an # attribute called `get_action_meanings`. hparams.eval_max_num_noops...
Tiny set of hparams for model - free PPO.
def rlmf_tiny(): """Tiny set of hparams for model-free PPO.""" hparams = rlmf_original() hparams = hparams.override_from_dict(rlmf_tiny_overrides()) hparams.batch_size = 2 hparams.base_algo_params = "ppo_original_tiny" hparams.add_hparam("ppo_epochs_num", 3) hparams.add_hparam("ppo_epoch_length", 2) ret...
Tiny DQN params.
def rlmf_dqn_tiny(): """Tiny DQN params.""" hparams = rlmf_original() hparams = hparams.override_from_dict(rlmf_tiny_overrides()) hparams.batch_size = 1 hparams.base_algo = "dqn" hparams.base_algo_params = "dqn_original_params" hparams.add_hparam("dqn_num_frames", 128) hparams.add_hparam("dqn_save_every...
Eval set of hparams for model - free PPO.
def rlmf_eval(): """Eval set of hparams for model-free PPO.""" hparams = rlmf_original() hparams.batch_size = 8 hparams.eval_sampling_temps = [0.0, 0.5, 1.0] hparams.eval_rl_env_max_episode_steps = -1 hparams.add_hparam("ppo_epoch_length", 128) hparams.add_hparam("ppo_optimization_batch_size", 32) hpara...
Feed - forward Gaussian.
def feed_forward_gaussian_fun(action_space, config, observations): """Feed-forward Gaussian.""" if not isinstance(action_space, gym.spaces.box.Box): raise ValueError("Expecting continuous action space.") mean_weights_initializer = tf.initializers.variance_scaling( scale=config.init_mean_factor) logst...
Curvature range.
def _curvature_range(self): """Curvature range. Returns: h_max_t, h_min_t ops """ self._curv_win = tf.get_variable("curv_win", dtype=tf.float32, trainable=False, shape=[self.curvature_wi...
Estimate of gradient Variance.
def _grad_variance(self): """Estimate of gradient Variance. Returns: C_t ops. """ grad_var_ops = [] tensor_to_avg = [] for t, g in zip(self._vars, self._grad): if isinstance(g, tf.IndexedSlices): tensor_to_avg.append( tf.reshape(tf.unsorted_segment_sum(g.values, ...
Distance to optimum.
def _dist_to_opt(self): """Distance to optimum. Returns: D_t ops """ dist_to_opt_ops = [] # Running average of the norm of gradient self._grad_norm = tf.sqrt(self._grad_norm_squared) avg_op = self._moving_averager.apply([self._grad_norm,]) dist_to_opt_ops.append(avg_op) with t...
Gradient sparsity.
def _grad_sparsity(self): """Gradient sparsity.""" # If the sparse minibatch gradient has 10 percent of its entries # non-zero, its sparsity is 0.1. # The norm of dense gradient averaged from full dataset # are roughly estimated norm of minibatch # sparse gradient norm * sqrt(sparsity) # An ...
Prepare Variables for YellowFin.
def _prepare_variables(self): """Prepare Variables for YellowFin. Returns: Grad**2, Norm, Norm**2, Mean(Norm**2) ops """ self._moving_averager = tf.train.ExponentialMovingAverage( decay=self._beta, zero_debias=self._zero_debias) # assert self._grad is not None and len(self._grad) > 0 ...
Get the cubic root.
def _get_cubic_root(self): """Get the cubic root.""" # We have the equation x^2 D^2 + (1-x)^4 * C / h_min^2 # where x = sqrt(mu). # We substitute x, which is sqrt(mu), with x = y + 1. # It gives y^3 + py = q # where p = (D^2 h_min^2)/(2*C) and q = -p. # We use the Vieta's substitution to com...
Get lr minimizing the surrogate.
def _get_lr_tensor(self): """Get lr minimizing the surrogate. Returns: The lr_t. """ lr = tf.squared_difference(1.0, tf.sqrt(self._mu)) / self._h_min return lr
Get the min mu which minimize the surrogate.
def _get_mu_tensor(self): """Get the min mu which minimize the surrogate. Returns: The mu_t. """ root = self._get_cubic_root() dr = self._h_max / self._h_min mu = tf.maximum( root**2, ((tf.sqrt(dr) - 1) / (tf.sqrt(dr) + 1))**2) return mu
YellowFin auto - tuning optimizer based on momentum SGD.
def _yellowfin(self): """YellowFin auto-tuning optimizer based on momentum SGD. Returns: YF ops (Curvature range, Grad_variance, Dist_to_opt, Single-Step, Auto-Tuning) """ # List for the returned Operations. yellowfin_ops = [] # Curvature range...
Applying gradients and tune hyperparams with YellowFin.
def apply_gradients(self, grads_and_vars, global_step=None, name=None): """Applying gradients and tune hyperparams with YellowFin. Args: grads_and_vars: List of (gradient, variable) pairs as returned by compute_gradients(). global_step: Optional Variable to increment by one after the ...
Compute gradients through momentum optimizer.
def compute_gradients(self, loss, var_list, global_step=None, gate_gradients=GATE_OP, aggregation_method=None, colocate_gradients_with_ops=False, name=N...
Adapted from TensorFlow Optimizer base class member function.
def minimize(self, loss, global_step=None, var_list=None, gate_gradients=GATE_OP, aggregation_method=None, colocate_gradients_with_ops=False, name=None, grad_loss=None): """Adapted from TensorFlow...
A stack of convolution blocks with residual connections.
def residual_dilated_conv(x, repeat, padding, name, hparams): """A stack of convolution blocks with residual connections.""" with tf.variable_scope(name): k = (hparams.kernel_height, hparams.kernel_width) dilations_and_kernels = [((2**i, 1), k) for i in range(hparams.num_hidden_...
ByteNet main step used for training.
def bytenet_internal(inputs, targets, hparams): """ByteNet, main step used for training.""" with tf.variable_scope("bytenet"): # Flatten inputs and extend length by 50%. inputs = tf.expand_dims(common_layers.flatten4d3d(inputs), axis=2) extend_length = tf.to_int32(0.5 * tf.to_float(tf.shape(inputs)[1]))...
Set of hyperparameters.
def bytenet_base(): """Set of hyperparameters.""" hparams = common_hparams.basic_params1() hparams.batch_size = 2048 hparams.hidden_size = 768 hparams.dropout = 0.2 hparams.symbol_dropout = 0.2 hparams.label_smoothing = 0.1 hparams.clip_grad_norm = 2.0 hparams.num_hidden_layers = 4 hparams.kernel_he...
Downloads and prepairs the dataset to be parsed by the data_generator.
def _download_and_parse_dataset(tmp_dir, train): """Downloads and prepairs the dataset to be parsed by the data_generator.""" file_path = generator_utils.maybe_download(tmp_dir, _SNLI_ZIP, _SNLI_URL) zip_ref = zipfile.ZipFile(file_path, 'r') zip_ref.extractall(tmp_dir) zip_ref.close() file_name = 'train' i...
Parse str to tokens and pos tags.
def _get_tokens_and_tags(parse_str): """Parse str to tokens and pos tags.""" tokens = [] parse_split = parse_str.split(' ') for p in parse_split: assert p.startswith('(') or p.endswith(')') if p.endswith(')'): token = p.replace(')', '') tokens.append(token) return tokens
Convert the dataset in to a simpler format.
def _parse_dataset(file_path, tmp_dir, train): """Convert the dataset in to a simpler format. This function creates two files. One for being processed to produce a vocab and another to generate the data. Args: file_path: string, path to the file to parse. tmp_dir: string, path to the directory to outp...
Read or create vocabulary.
def _get_or_generate_vocab(tmp_dir, vocab_filename, vocab_size): """Read or create vocabulary.""" vocab_filepath = os.path.join(tmp_dir, vocab_filename) print('Vocab file written to: ' + vocab_filepath) if tf.gfile.Exists(vocab_filepath): gs = text_encoder.SubwordTextEncoder(vocab_filepath) return gs ...
Generate example dicts.
def snli_token_generator(tmp_dir, train, vocab_size): """Generate example dicts.""" _download_and_parse_dataset(tmp_dir, train) symbolizer_vocab = _get_or_generate_vocab( tmp_dir, 'vocab.subword_text_encoder', vocab_size) file_name = 'train' if train else 'dev' data_file = os.path.join(tmp_dir, file_n...
Split items into num_shards groups.
def shard(items, num_shards): """Split items into num_shards groups.""" sharded = [] num_per_shard = len(items) // num_shards start = 0 for _ in range(num_shards): sharded.append(items[start:start + num_per_shard]) start += num_per_shard remainder = len(items) % num_shards start = len(items) - re...
An initializer function for random normal coefficients.
def RandomNormalInitializer(stddev=1e-2): """An initializer function for random normal coefficients.""" def init(shape, rng): return (stddev * backend.random.normal(rng, shape)).astype('float32') return init
An initializer function for random Glorot - scaled coefficients.
def GlorotNormalInitializer(out_dim=0, in_dim=1, scale=onp.sqrt(2)): """An initializer function for random Glorot-scaled coefficients.""" def init(shape, rng): fan_in, fan_out = shape[in_dim], shape[out_dim] size = onp.prod(onp.delete(shape, [in_dim, out_dim])) std = scale / np.sqrt((fan_in + fan_out) /...
An initializer function for random uniform Glorot - scaled coefficients.
def GlorotUniformInitializer(out_dim=0, in_dim=1): """An initializer function for random uniform Glorot-scaled coefficients.""" def init(shape, rng): fan_in, fan_out = shape[in_dim], shape[out_dim] std = np.sqrt(2.0 / (fan_in + fan_out)) a = np.sqrt(3.0) * std return backend.random.uniform(rng, shap...
Make a n + 1 dim one - hot array from n dim int - categorical array.
def one_hot(x, size, dtype=np.float32): """Make a n+1 dim one-hot array from n dim int-categorical array.""" return np.array(x[..., np.newaxis] == np.arange(size), dtype)
Apply log softmax to x: log - normalize along the given axis.
def LogSoftmax(x, params, axis=-1, **kwargs): """Apply log softmax to x: log-normalize along the given axis.""" del params, kwargs return x - backend.logsumexp(x, axis, keepdims=True)
Apply softmax to x: exponentiate and normalize along the given axis.
def Softmax(x, params, axis=-1, **kwargs): """Apply softmax to x: exponentiate and normalize along the given axis.""" del params, kwargs return np.exp(x - backend.logsumexp(x, axis, keepdims=True))
Convert padding string to list of pairs of pad values.
def padtype_to_pads(in_shape, window_shape, window_strides, padding): """Convert padding string to list of pairs of pad values.""" padding = padding.upper() if padding == 'SAME': out_shape = onp.ceil( onp.true_divide(in_shape, window_strides)).astype(int) pad_sizes = [max((out_size - 1) * stride +...
Output shape of a flatten layer.
def _flatten_output_shape(input_shape, num_axis_to_keep=1): """Output shape of a flatten layer.""" if num_axis_to_keep >= len(input_shape): raise ValueError( "num_axis_to_keep[%d] should be less than input's rank[%d]" % (num_axis_to_keep, len(input_shape))) return tuple(input_shape[:num_axis_t...
Helper to initialize batch norm params.
def _batch_norm_new_params(input_shape, rng, axis=(0, 1, 2), center=True, scale=True, **kwargs): """Helper to initialize batch norm params.""" del rng, kwargs axis = (axis,) if np.isscalar(axis) else axis shape = tuple(d for i, d in enumerate(input_shape) if i not in axis) beta = np...
Layer construction function for a batch normalization layer.
def BatchNorm(x, params, axis=(0, 1, 2), epsilon=1e-5, center=True, scale=True, **unused_kwargs): """Layer construction function for a batch normalization layer.""" mean = np.mean(x, axis, keepdims=True) # Fast but less numerically-stable variance calculation than np.var. m1 = np.mean(x**2, axis, ...
Helper: compute the output shape for the pooling layer.
def _pooling_output_shape(input_shape, pool_size=(2, 2), strides=None, padding='VALID'): """Helper: compute the output shape for the pooling layer.""" dims = (1,) + pool_size + (1,) # NHWC spatial_strides = strides or (1,) * len(pool_size) strides = (1,) + spatial_strides + (1,) pad...
Helper: general pooling computation used in pooling layers later.
def _pooling_general(inputs, reducer, init_val, rescaler=None, pool_size=(2, 2), strides=None, padding='VALID'): """Helper: general pooling computation used in pooling layers later.""" spatial_strides = strides or (1,) * len(pool_size) rescale = rescaler(pool_size, spatial_strides, padding) i...
Layer construction function for a dropout layer with given rate.
def Dropout(x, params, rate=0.0, mode='train', rng=None, **kwargs): """Layer construction function for a dropout layer with given rate.""" del params, kwargs if rng is None: msg = ('Dropout layer requires apply_fun to be called with a rng keyword ' 'argument. That is, instead of `Dropout(params, in...
Helper to calculate the kernel shape.
def _kernel_shape(self, input_shape): """Helper to calculate the kernel shape.""" kernel_size_iter = iter(self._kernel_size) return [self._filters if c == 'O' else input_shape[self._lhs_spec.index('C')] if c == 'I' else next(kernel_size_iter) for c in self._rhs_spec]
Compute the shape of a conv given input shapes in canonical order.
def _conv_shape_tuple(self, lhs_shape, rhs_shape, strides, pads): """Compute the shape of a conv given input shapes in canonical order.""" if isinstance(pads, str): pads = padtype_to_pads(lhs_shape[2:], rhs_shape[2:], strides, pads) if len(pads) != len(lhs_shape) - 2: msg = 'Wrong number of expl...
Utility for convolution dimension permutations relative to Conv HLO.
def _conv_general_permutations(self, dimension_numbers): """Utility for convolution dimension permutations relative to Conv HLO.""" lhs_spec, rhs_spec, out_spec = dimension_numbers lhs_char, rhs_char, out_char = ('N', 'C'), ('O', 'I'), ('N', 'C') charpairs = (lhs_char, rhs_char, out_char) for i, (a,...
Generalized computation of conv shape.
def _conv_general_shape_tuple(self, lhs_shape, rhs_shape, window_strides, padding, dimension_numbers): """Generalized computation of conv shape.""" lhs_perm, rhs_perm, out_perm = self._conv_general_permutations( dimension_numbers) lhs_trans = onp.take(lhs_shape, lhs_p...
Factory for dopamine agent initialization.
def get_create_agent(agent_kwargs): """Factory for dopamine agent initialization. Args: agent_kwargs: dict of BatchDQNAgent parameters Returns: Function(sess, environment, summary_writer) -> BatchDQNAgent instance. """ def create_agent(sess, environment, summary_writer=None): """Creates a DQN a...
Factory for dopamine environment initialization function.
def get_create_batch_env_fun(batch_env_fn, time_limit): """Factory for dopamine environment initialization function. Args: batch_env_fn: function(in_graph: bool) -> batch environment. time_limit: time steps limit for environment. Returns: function (with optional, unused parameters) initializing envi...
Split hparams based on key prefixes.
def _parse_hparams(hparams): """Split hparams, based on key prefixes. Args: hparams: hyperparameters Returns: Tuple of hparams for respectably: agent, optimizer, runner, replay_buffer. """ prefixes = ["agent_", "optimizer_", "runner_", "replay_buffer_"] ret = [] for prefix in prefixes: ret_...
Build WrappedReplayBuffer with custom OutOfGraphReplayBuffer.
def _build_replay_buffer(self, use_staging): """Build WrappedReplayBuffer with custom OutOfGraphReplayBuffer.""" replay_buffer_kwargs = dict( observation_shape=dqn_agent.NATURE_DQN_OBSERVATION_SHAPE, stack_size=dqn_agent.NATURE_DQN_STACK_SIZE, replay_capacity=self._replay_capacity, ...
Append artificial_done to * args and run parent method.
def add(self, observation, action, reward, terminal, *args): """Append artificial_done to *args and run parent method.""" # If this will be a problem for maintenance, we could probably override # DQNAgent.add() method instead. artificial_done = self._artificial_done and terminal args = list(args) ...
Step.
def step(self, actions): """Step.""" self._elapsed_steps += 1 obs, rewards, dones = \ [np.array(r) for r in self.batch_env.step(actions)] if self._elapsed_steps > self._max_episode_steps: done = True if self._elapsed_steps > self._max_episode_steps + 1: rewards.fill(0) el...
Set of hyperparameters.
def text_cnn_base(): """Set of hyperparameters.""" hparams = common_hparams.basic_params1() hparams.batch_size = 4096 hparams.max_length = 256 hparams.clip_grad_norm = 0. # i.e. no gradient clipping hparams.optimizer_adam_epsilon = 1e-9 hparams.learning_rate_schedule = "legacy" hparams.learning_rate_de...
Hparams for next_frame_glow.
def next_frame_glow_hparams(): """Hparams for next_frame_glow.""" hparams = glow.glow_hparams() # Possible modes are conditional and unconditional hparams.add_hparam("gen_mode", "conditional") hparams.add_hparam("learn_top_scale", False) hparams.add_hparam("condition_all_levels", True) # For each video, s...
Hparams to reproduce bits - per - pixel results on BAIR action - free dataset.
def next_frame_glow_bair_quant(): """Hparams to reproduce bits-per-pixel results on BAIR action-free dataset.""" hparams = next_frame_glow_hparams() hparams.video_num_input_frames = 3 hparams.video_num_target_frames = 10 hparams.num_train_frames = 4 hparams.num_cond_latents = 3 hparams.depth = 24 hparam...
Hparams for qualitative video generation results.
def next_frame_glow_bair_qual(): """Hparams for qualitative video generation results.""" hparams = next_frame_glow_bair_quant() hparams.coupling = "additive" hparams.temperature = 0.5 hparams.coupling_width = 392 return hparams
Hparams for qualitative and quantitative results on shapes dataset.
def next_frame_glow_shapes(): """Hparams for qualitative and quantitative results on shapes dataset.""" hparams = next_frame_glow_bair_quant() hparams.video_num_input_frames = 1 hparams.video_num_target_frames = 2 hparams.num_train_frames = 2 hparams.num_cond_latents = 1 hparams.coupling = "additive" hp...
Get z^ { cond } _ { t } given z^ { 1.. t - 1 }.
def get_cond_latents(all_latents=None, hparams=None): """Get z^{cond}_{t} given z^{1..t-1}. Args: all_latents: list of list of tensors, outer-size equals no.of time_steps-1 inner-size equals hparams.n_levels. hparams: See next_frame_glow_hparams. Returns: cond_latent...
Small fully connected model.
def basic_fc_small(): """Small fully connected model.""" hparams = common_hparams.basic_params1() hparams.learning_rate = 0.1 hparams.batch_size = 128 hparams.hidden_size = 256 hparams.num_hidden_layers = 2 hparams.initializer = "uniform_unit_scaling" hparams.initializer_gain = 1.0 hparams.weight_deca...
A stack of layers.
def _layer_stack(mp, inputs, self_attention_bias, layers, hparams, encoder_output=None, encoder_decoder_attention_bias=None): """A stack of layers. Args: mp: a Parallelism object inputs: a list of Tensors ...
Set of hyperparameters.
def transformer_symshard_base(): """Set of hyperparameters.""" hparams = common_hparams.basic_params1() hparams.hidden_size = 256 hparams.batch_size = 2048 hparams.max_length = 0 # All hyperparameters ending in "dropout" are automatically set to 0.0 # when not in training mode. hparams.layer_prepostproc...
Image generator for Imagenet 64x64 downsampled images.
def imagenet_pixelrnn_generator(tmp_dir, training, size=_IMAGENET_SMALL_IMAGE_SIZE): """Image generator for Imagenet 64x64 downsampled images. It assumes that the data has been downloaded from http://image-net.org/small/*_32x32.tar or http://image...
Preprocessing used for Imagenet and similar problems.
def imagenet_preprocess_example(example, mode, resize_size=None, normalize=True): """Preprocessing used for Imagenet and similar problems.""" resize_size = resize_size or [299, 299] assert resize_size[0] == resize_size[1] image = example["inputs"] if mode == tf.estimator.ModeK...
Crops the given image using the provided offsets and sizes.
def _crop(image, offset_height, offset_width, crop_height, crop_width): """Crops the given image using the provided offsets and sizes. Note that the method doesn't assume we know the input image size but it does assume we know the input image rank. Args: image: `Tensor` image of shape [height, width, chan...
Generates cropped_image using a one of the bboxes randomly distorted.
def distorted_bounding_box_crop(image, bbox, min_object_covered=0.1, aspect_ratio_range=(0.75, 1.33), area_range=(0.05, 1.0), max_attempts=100, ...
Make a random crop of ( size x size ).
def _random_crop(image, size): """Make a random crop of (`size` x `size`).""" bbox = tf.constant([0.0, 0.0, 1.0, 1.0], dtype=tf.float32, shape=[1, 1, 4]) random_image, bbox = distorted_bounding_box_crop( image, bbox, min_object_covered=0.1, aspect_ratio_range=(3. / 4, 4. / 3.), area_...
At least x of a and b Tensors are true.
def _at_least_x_are_true(a, b, x): """At least `x` of `a` and `b` `Tensors` are true.""" match = tf.equal(a, b) match = tf.cast(match, tf.int32) return tf.greater_equal(tf.reduce_sum(match), x)
Rescale the image by scaling the smaller spatial dimension to size.
def _do_scale(image, size): """Rescale the image by scaling the smaller spatial dimension to `size`.""" shape = tf.cast(tf.shape(image), tf.float32) w_greater = tf.greater(shape[0], shape[1]) shape = tf.cond(w_greater, lambda: tf.cast([shape[0] / shape[1] * size, size], tf.int32), ...
Crops to center of image with specified size.
def _center_crop(image, size): """Crops to center of image with specified `size`.""" image_height = tf.shape(image)[0] image_width = tf.shape(image)[1] offset_height = ((image_height - size) + 1) / 2 offset_width = ((image_width - size) + 1) / 2 image = _crop(image, offset_height, offset_width, size, size)...
Normalize the image to zero mean and unit variance.
def _normalize(image): """Normalize the image to zero mean and unit variance.""" offset = tf.constant(MEAN_RGB, shape=[1, 1, 3]) image -= offset scale = tf.constant(STDDEV_RGB, shape=[1, 1, 3]) image /= scale return image
Preprocesses the given image for evaluation.
def preprocess_for_train(image, image_size=224, normalize=True): """Preprocesses the given image for evaluation. Args: image: `Tensor` representing an image of arbitrary size. image_size: int, how large the output image should be. normalize: bool, if True the image is normalized. Returns: A prep...
Preprocesses the given image for evaluation.
def preprocess_for_eval(image, image_size=224, normalize=True): """Preprocesses the given image for evaluation. Args: image: `Tensor` representing an image of arbitrary size. image_size: int, how large the output image should be. normalize: bool, if True the image is normalized. Returns: A prepr...
Factor - based learning rate schedule.
def MultifactorSchedule(history=None, factors="constant * linear_warmup * rsqrt_decay", constant=0.1, warmup_steps=100, decay_factor=0.5, steps_per_decay=20000): """Factor-based learning rate schedu...
Learning rate that decreases when eval metric stalls.
def EvalAdjustingSchedule(history, constant=0.1, steps_to_decrease=20, improvement_margin=0.001, decrease_rate=1.5, history_mode="eval", metric="metrics/accuracy"):...
Project encoder hidden state under num_blocks using projection tensors.
def project_hidden(x, projection_tensors, hidden_size, num_blocks): """Project encoder hidden state under num_blocks using projection tensors. Args: x: Encoder hidden state of shape [batch_size, latent_dim, hidden_size]. projection_tensors: Projection tensors used to project the hidden state. hidden_s...
Slice encoder hidden state under num_blocks.
def slice_hidden(x, hidden_size, num_blocks): """Slice encoder hidden state under num_blocks. Args: x: Encoder hidden state of shape [batch_size, latent_dim, hidden_size]. hidden_size: Dimension of the latent space. num_blocks: Number of blocks in DVQ. Returns: Sliced states of shape [batch_size...
Find the nearest element in means to elements in x.
def nearest_neighbor(x, means, block_v_size, random_top_k=1, soft_em=False, num_samples=1, sum_over_latents=False, summary=True): """Find the nearest element in means to e...
Compute nearest neighbors and loss for training the embeddings via DVQ.
def embedding_lookup(x, means, num_blocks, block_v_size, bottleneck_kind="dvq", random_top_k=1, soft_em=False, num_samples=1, do_hard_gumbel_softmax=Fal...
Turn x_bit representing numbers bitwise ( lower - endian ) to int tensor.
def bit_to_int(x_bit, num_bits, base=2): """Turn x_bit representing numbers bitwise (lower-endian) to int tensor. Args: x_bit: Tensor containing numbers in a particular base to be converted to int. num_bits: Number of bits in the representation. base: Base of the representation. Returns: I...
Turn x_int into a bitwise ( lower - endian ) tensor and embed densly.
def int_to_bit_embed(x_int, num_bits, embedding_size, base=2): """Turn x_int into a bitwise (lower-endian) tensor and embed densly.""" shape = common_layers.shape_list(x_int) inputs = int_to_bit(x_int, num_bits, base=base) inputs = tf.reshape(inputs, shape[:-1] + [shape[-1] * 8]) inputs = 2.0 * tf.to_float(in...
Embedding function that takes discrete latent and returns embedding.
def embed(x, hidden_size, z_size, filter_size, bottleneck_kind="dvq", soft_em=False, num_blocks=2, num_residuals=1, block_v_size=None, means=None, name=None): """Embedding function that takes discrete latent and return...
Simple variational autoencoder without discretization.
def vae(x, z_size, name=None): """Simple variational autoencoder without discretization. Args: x: Input to the discretization bottleneck. z_size: Number of bits, where discrete codes range from 1 to 2**z_size. name: Name for the bottleneck scope. Returns: Embedding function, latent, loss, mu and...
Sample from the Gumbel distribution protect from overflows.
def gumbel_sample(shape): """Sample from the Gumbel distribution, protect from overflows. Args: shape: Shape of Gumbel samples. Returns: Noise drawn from Gumbel distribution. """ uniform_samples = tf.random_uniform(shape, minval=0.00001, maxval=0.99998) return -tf.log(-tf.log(uniform_samples))
Gumbel softmax discretization bottleneck.
def gumbel_softmax(x, z_size, mode, softmax_k=0, temperature_warmup_steps=150000, summary=True, name=None): """Gumbel softmax discretization bottleneck. Args: x: Input to the discretization bottlen...
Discretization bottleneck.
def discrete_bottleneck(inputs, hidden_size, z_size, filter_size, mode=None, bottleneck_kind="dvq", num_blocks=2, num_residuals=1, ...
Predict a sequence of bits ( a latent ) with LSTM both training and infer.
def predict_bits_with_lstm(prediction_source, state_size, total_num_bits, target_bits=None, extra_inputs=None, bits_at_once=8, temperature=1.0, dropout=0.1): """Predict a sequence of bits (a latent) with LSTM, both training and infer. Given a tensor on which th...
Get lookup table for VQ bottleneck.
def get_vq_codebook(codebook_size, hidden_size): """Get lookup table for VQ bottleneck.""" with tf.variable_scope("vq", reuse=tf.AUTO_REUSE): means = tf.get_variable( name="means", shape=[codebook_size, hidden_size], initializer=tf.uniform_unit_scaling_initializer()) ema_count = tf....
Find the nearest element in means to elements in x.
def vq_nearest_neighbor(x, means, soft_em=False, num_samples=10, temperature=None): """Find the nearest element in means to elements in x.""" bottleneck_size = common_layers.shape_list(means)[0] x_norm_sq = tf.reduce_sum(tf.square(x), axis=-1, keepdims=True) means_norm_sq = tf.reduce_sum...
Simple vector quantized discrete bottleneck.
def vq_discrete_bottleneck(x, bottleneck_bits, beta=0.25, decay=0.999, epsilon=1e-5, soft_em=False, num_samples=10): """Simple vector quantized discrete bot...
Discretize each x into one of codebook_size codes.
def vq_body(x, codebook_size, beta=0.25, decay=0.999, epsilon=1e-5, soft_em=False, num_samples=10, temperature=None, do_update=True): """Discretize each x into one of codebook_size codes.""" x_shape = common_layers.shape...
Compute the loss of large vocab tensors using a VQAE codebook.
def vq_loss(x, targets, codebook_size, beta=0.25, decay=0.999, epsilon=1e-5, soft_em=False, num_samples=10, temperature=None, do_update=True): """Compute the loss of large vocab tensors using a VQAE codebook. ...
Simple undiscretization from vector quantized representation.
def vq_discrete_unbottleneck(x, hidden_size): """Simple undiscretization from vector quantized representation.""" x_shape = common_layers.shape_list(x) x = tf.to_float(x) bottleneck_size = common_layers.shape_list(x)[-1] means, _, _ = get_vq_codebook(bottleneck_size, hidden_size) result = tf.matmul(tf.resha...
Sample from Gumbel - Softmax and compute neighbors and losses.
def gumbel_softmax_nearest_neighbor_dvq(x, means, block_v_size, hard=False, temperature_init=1.2, num_samples=1, ...
VQ - VAE using Gumbel - Softmax.
def gumbel_softmax_discrete_bottleneck(x, bottleneck_bits, beta=0.25, decay=0.999, epsilon=1e-5, temperature_warmup_steps=150...
Simple discretization through tanh flip bottleneck_noise many bits.
def tanh_discrete_bottleneck(x, bottleneck_bits, bottleneck_noise, discretize_warmup_steps, mode): """Simple discretization through tanh, flip bottleneck_noise many bits.""" x = tf.layers.dense(x, bottleneck_bits, name="tanh_discrete_bottleneck") d0 = tf.stop_gradient(2.0 * tf.to_floa...
Simple un - discretization from tanh.
def tanh_discrete_unbottleneck(x, hidden_size): """Simple un-discretization from tanh.""" x = tf.layers.dense(x, hidden_size, name="tanh_discrete_unbottleneck") return x
Improved semantic hashing bottleneck.
def isemhash_bottleneck(x, bottleneck_bits, bottleneck_noise, discretize_warmup_steps, mode, isemhash_noise_dev=0.5, isemhash_mix_prob=0.5): """Improved semantic hashing bott...
Improved semantic hashing un - bottleneck.
def isemhash_unbottleneck(x, hidden_size, isemhash_filter_size_multiplier=1.0): """Improved semantic hashing un-bottleneck.""" filter_size = int(hidden_size * isemhash_filter_size_multiplier) x = 0.5 * (x - 1.0) # Move from [-1, 1] to [0, 1]. with tf.variable_scope("isemhash_unbottleneck"): h1a = tf.layers...
Meta - function calling all the above bottlenecks with hparams.
def parametrized_bottleneck(x, hparams): """Meta-function calling all the above bottlenecks with hparams.""" if hparams.bottleneck_kind == "tanh_discrete": d, _ = tanh_discrete_bottleneck( x, hparams.bottleneck_bits, hparams.bottleneck_noise * 0.5, hparams.discretize_warmup_steps, hparams.mode) ...
Meta - function calling all the above un - bottlenecks with hparams.
def parametrized_unbottleneck(x, hidden_size, hparams): """Meta-function calling all the above un-bottlenecks with hparams.""" if hparams.bottleneck_kind == "tanh_discrete": return tanh_discrete_unbottleneck(x, hidden_size) if hparams.bottleneck_kind == "isemhash": return isemhash_unbottleneck(x, hidden_s...
Create hyperpameters for inverse autoregressive flows.
def iaf_hparams(hidden_size=512, filter_size=4096): """Create hyperpameters for inverse autoregressive flows. Args: hidden_size: Width of attention layers and neural network output layer. filter_size: Hidden layer width for neural network. Returns: hparams: Hyperpameters with basic presets for inver...
Returns a set containing the original vocabulary.
def _original_vocab(tmp_dir): """Returns a set containing the original vocabulary. This is important for comparing with published results. Args: tmp_dir: directory containing dataset. Returns: a set of strings """ vocab_url = ("http://download.tensorflow.org/models/LM_LSTM_CNN/" "v...