refine docstring for parakeet.data and deep voice 3, wavenet and clarinet

examples/clarinet/utils.py

@@ -67,13 +67,13 @@ def save_checkpoint(model, optim, checkpoint_dir, global_step):
 
 def load_model(model, path):
     model_dict, _ = dg.load_dygraph(path)
-    model.state_dict(model_dict)
+    model.set_dict(model_dict)
     print("loaded model from {}.pdparams".format(path))
 
 
 def load_checkpoint(model, optim, path):
     model_dict, optim_dict = dg.load_dygraph(path)
-    model.state_dict(model_dict)
+    model.set_dict(model_dict)
     print("loaded model from {}.pdparams".format(path))
     if optim_dict:
         optim.set_dict(optim_dict)

examples/deepvoice3/utils.py

@@ -69,7 +69,6 @@ def make_model(n_speakers, speaker_dim, speaker_embed_std, embed_dim,
         padding_idx=None,
         embedding_weight_std=embedding_std,
         convolutions=encoder_convolutions,
-        max_positions=max_positions,
         dropout=dropout)
     if freeze_embedding:
         freeze(enc.embed)
@@ -91,7 +90,6 @@ def make_model(n_speakers, speaker_dim, speaker_embed_std, embed_dim,
         mel_dim,
         r=r,
         max_positions=max_positions,
-        padding_idx=padding_idx,
         preattention=prenet_convolutions,
         convolutions=attentive_convolutions,
         attention=attention,

parakeet/data/batch.py

@@ -12,13 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-functions to make batch for arrays which satisfy some conditions.
+Utility functions to create batch for arrays which satisfy some conditions.
+Batch functions for text sequences, audio and spectrograms are provided.
 """
 import numpy as np
 
 
 class TextIDBatcher(object):
-    """A wrapper class for a function to build a functor, which holds the configs to pass to the function."""
+    """A wrapper class for `batch_text_id`."""
 
     def __init__(self, pad_id=0, dtype=np.int64):
         self.pad_id = pad_id
@@ -30,9 +31,15 @@ class TextIDBatcher(object):
 
 
 def batch_text_id(minibatch, pad_id=0, dtype=np.int64):
-    """
-    minibatch: List[Example]
-    Example: ndarray, shape(T,), dtype: int64
+    """Pad sequences to text_ids to the largest length and batch them.
+    
+    Args:
+        minibatch (List[np.ndarray]): list of rank-1 arrays, shape(T,), dtype: np.int64, text_ids.
+        pad_id (int, optional): the id which correspond to the special pad token. Defaults to 0.
+        dtype (np.dtype, optional): the data dtype of the output. Defaults to np.int64.
+
+    Returns:
+        np.ndarray: rank-2 array of text_ids, shape(B, T), B stands for batch_size, T stands for length. The output batch.
     """
     peek_example = minibatch[0]
     assert len(peek_example.shape) == 1, "text example is an 1D tensor"
@@ -53,6 +60,8 @@ def batch_text_id(minibatch, pad_id=0, dtype=np.int64):
 
 
 class WavBatcher(object):
+    """A wrapper class for `batch_wav`."""
+
     def __init__(self, pad_value=0., dtype=np.float32):
         self.pad_value = pad_value
         self.dtype = dtype
@@ -63,19 +72,25 @@ class WavBatcher(object):
 
 
 def batch_wav(minibatch, pad_value=0., dtype=np.float32):
+    """pad audios to the largest length and batch them.
+
+    Args:
+        minibatch (List[np.ndarray]): list of rank-1 float arrays(mono-channel audio, shape(T,)) or list of rank-2 float arrays(multi-channel audio, shape(C, T), C stands for numer of channels, T stands for length), dtype: float.
+        pad_value (float, optional): the pad value. Defaults to 0..
+        dtype (np.dtype, optional): the data type of the output. Defaults to np.float32.
+
+    Returns:
+        np.ndarray: the output batch. It is a rank-2 float array of shape(B, T) if the minibatch is a list of mono-channel audios, or a rank-3 float array of shape(B, C, T) if the minibatch is a list of multi-channel audios.
     """
-    minibatch: List[Example]
-    Example: ndarray, shape(C, T) for multi-channel wav, shape(T,) for mono-channel wav, dtype: float32 
-    """
-    # detect data format, maybe better to specify it in __init__
+
     peek_example = minibatch[0]
     if len(peek_example.shape) == 1:
         mono_channel = True
     elif len(peek_example.shape) == 2:
         mono_channel = False
 
-    lengths = [example.shape[-1] for example in minibatch
-               ]  # assume (channel, n_samples) or (n_samples, )
+    # assume (channel, n_samples) or (n_samples, )
+    lengths = [example.shape[-1] for example in minibatch]
     max_len = np.max(lengths)
 
     batch = []
@@ -90,12 +105,14 @@ def batch_wav(minibatch, pad_value=0., dtype=np.float32):
             batch.append(
                 np.pad(example, [(0, 0), (0, pad_len)],
                        mode='constant',
-                       constant_values=pad_value))  # what about PCM, no
+                       constant_values=pad_value))
 
     return np.array(batch, dtype=dtype)
 
 
 class SpecBatcher(object):
+    """A wrapper class for `batch_spec`"""
+
     def __init__(self, pad_value=0., dtype=np.float32):
         self.pad_value = pad_value
         self.dtype = dtype
@@ -106,9 +123,15 @@ class SpecBatcher(object):
 
 
 def batch_spec(minibatch, pad_value=0., dtype=np.float32):
-    """
-    minibatch: List[Example]
-    Example: ndarray, shape(C, F, T) for multi-channel spectrogram, shape(F, T) for mono-channel spectrogram, dtype: float32 
+    """Pad spectra to the largest length and batch them.
+
+    Args:
+        minibatch (List[np.ndarray]): list of rank-2 arrays of shape(F, T) for mono-channel spectrograms, or list of rank-3 arrays of shape(C, F, T) for multi-channel spectrograms(F stands for frequency bands.), dtype: float.
+        pad_value (float, optional): the pad value. Defaults to 0..
+        dtype (np.dtype, optional): data type of the output. Defaults to np.float32.
+
+    Returns:
+        np.ndarray: a rank-3 array of shape(B, F, T) when the minibatch is a list of mono-channel spectrograms, or a rank-4 array of shape(B, C, F, T) when the minibatch is a list of multi-channel spectorgrams.
     """
     # assume (F, T) or (C, F, T)
     peek_example = minibatch[0]
@@ -117,8 +140,8 @@ def batch_spec(minibatch, pad_value=0., dtype=np.float32):
     elif len(peek_example.shape) == 3:
         mono_channel = False
 
-    lengths = [example.shape[-1] for example in minibatch
-               ]  # assume (channel, F, n_frame) or (F, n_frame)
+    # assume (channel, F, n_frame) or (F, n_frame)
+    lengths = [example.shape[-1] for example in minibatch]
     max_len = np.max(lengths)
 
     batch = []
@@ -133,6 +156,6 @@ def batch_spec(minibatch, pad_value=0., dtype=np.float32):
             batch.append(
                 np.pad(example, [(0, 0), (0, 0), (0, pad_len)],
                        mode='constant',
-                       constant_values=pad_value))  # what about PCM, no
+                       constant_values=pad_value))
 
     return np.array(batch, dtype=dtype)

parakeet/data/datacargo.py

@@ -25,6 +25,17 @@ class DataCargo(object):
                  shuffle=False,
                  batch_sampler=None,
                  drop_last=False):
+        """An Iterable object of batches. It requires a dataset, a batch function and a sampler. The sampler yields the example ids, then the corresponding examples in the dataset are collected and transformed into a batch with the batch function.
+
+        Args:
+            dataset (Dataset): the dataset used to build a data cargo.
+            batch_fn (callable, optional): a callable that takes a list of examples of `dataset` and return a batch, it can be None if the dataset has a `_batch_examples` method which satisfy the requirement. Defaults to None.
+            batch_size (int, optional): number of examples in a batch. Defaults to 1.
+            sampler (Sampler, optional): an iterable of example ids(intergers), the example ids are used to pick examples. Defaults to None.
+            shuffle (bool, optional): when sampler is not provided, shuffle = True creates a RandomSampler and shuffle=False creates a SequentialSampler internally. Defaults to False.
+            batch_sampler (BatchSampler, optional): an iterable of lists of example ids(intergers), the list is used to pick examples, `batch_sampler` option is mutually exclusive with `batch_size`, `shuffle`, `sampler`, and `drop_last`. Defaults to None.
+            drop_last (bool, optional): whether to drop the last minibatch. Defaults to False.
+        """
         self.dataset = dataset
         self.batch_fn = batch_fn or self.dataset._batch_examples
 
@@ -59,11 +70,12 @@ class DataCargo(object):
         return DataIterator(self)
 
     def __call__(self):
+        # protocol for paddle's DataLoader
         return DataIterator(self)
 
     @property
     def _auto_collation(self):
-        # we will auto batching
+        # use auto batching
         return self.batch_sampler is not None
 
     @property
@@ -79,6 +91,11 @@ class DataCargo(object):
 
 class DataIterator(object):
     def __init__(self, loader):
+        """Iterator object of DataCargo.
+
+        Args:
+            loader (DataCargo): the data cargo to iterate.
+        """
         self.loader = loader
         self._dataset = loader.dataset
 
@@ -90,11 +107,9 @@ class DataIterator(object):
         return self
 
     def __next__(self):
-
-        index = self._next_index(
-        )  # may raise StopIteration, TODO(chenfeiyu): use dynamic batch size
-        minibatch = [self._dataset[i] for i in index
-                     ]  # we can abstract it, too to use dynamic batch size
+        # TODO(chenfeiyu): use dynamic batch size
+        index = self._next_index()
+        minibatch = [self._dataset[i] for i in index]
         minibatch = self._batch_fn(minibatch)  # list[Example] -> Batch
         return minibatch
 

parakeet/data/dataset.py

@@ -17,9 +17,23 @@ import numpy as np
 
 
 class DatasetMixin(object):
-    """standard indexing interface for dataset."""
+    """Standard indexing interface for dataset. Inherit this class to 
+    get the indexing interface. Since it is a mixin class which does 
+    not have an `__init__` class, the subclass not need to call  
+    `super().__init__()`.
+    """
 
     def __getitem__(self, index):
+        """Standard indexing interface for dataset.
+
+        Args:
+            index (slice, list[int], np.array or int): the index. if can be int, slice, list of integers, or ndarray of integers. It calls `get_example` to pick an example. 
+
+        Returns:
+            Example, or List[Example]:  If `index` is an interger, it returns an 
+                    example. If `index` is a slice, a list of intergers or an array of intergers,
+                    it returns a list of examples.
+        """
         if isinstance(index, slice):
             start, stop, step = index.indices(len(self))
             return [
@@ -32,6 +46,12 @@ class DatasetMixin(object):
             return self.get_example(index)
 
     def get_example(self, i):
+        """Get an example from the dataset. Custom datasets should have 
+        this method implemented.
+
+        Args:
+            i (int): example index.
+        """
         raise NotImplementedError
 
     def __len__(self):
@@ -43,9 +63,13 @@ class DatasetMixin(object):
 
 
 class TransformDataset(DatasetMixin):
-    """Transform a dataset to another with a transform."""
-
     def __init__(self, dataset, transform):
+        """Dataset which is transformed from another with a transform.
+
+        Args:
+            dataset (DatasetMixin): the base dataset.
+            transform (callable): the transform which takes an example of the base dataset as parameter and return a new example.
+        """
         self._dataset = dataset
         self._transform = transform
 
@@ -53,14 +77,17 @@ class TransformDataset(DatasetMixin):
         return len(self._dataset)
 
     def get_example(self, i):
-        # CAUTION: only int is supported?
-        # CAUTION: dataset support support __getitem__ and __len__
         in_data = self._dataset[i]
         return self._transform(in_data)
 
 
 class CacheDataset(DatasetMixin):
     def __init__(self, dataset):
+        """A lazy cache of the base dataset.
+
+        Args:
+            dataset (DatasetMixin): the base dataset to cache.
+        """
         self._dataset = dataset
         self._cache = dict()
 
@@ -75,6 +102,11 @@ class CacheDataset(DatasetMixin):
 
 class TupleDataset(object):
     def __init__(self, *datasets):
+        """A compound dataset made from several datasets of the same length. An example of the `TupleDataset` is a tuple of examples from the constituent datasets.
+
+        Args:
+            datasets: tuple[DatasetMixin], the constituent datasets.
+        """
         if not datasets:
             raise ValueError("no datasets are given")
         length = len(datasets[0])
@@ -105,6 +137,11 @@ class TupleDataset(object):
 
 class DictDataset(object):
     def __init__(self, **datasets):
+        """A compound dataset made from several datasets of the same length. An example of the `DictDataset` is a dict of examples from the constituent datasets.
+
+        Args:
+            datasets: Dict[DatasetMixin], the constituent datasets.
+        """
         if not datasets:
             raise ValueError("no datasets are given")
         length = None
@@ -134,6 +171,14 @@ class DictDataset(object):
 
 class SliceDataset(DatasetMixin):
     def __init__(self, dataset, start, finish, order=None):
+        """A Dataset which is a slice of the base dataset.
+
+        Args:
+            dataset (DatasetMixin): the base dataset.
+            start (int): the start of the slice.
+            finish (int): the end of the slice, not inclusive.
+            order (List[int], optional): the order, it is a permutation of the valid example ids of the base dataset. If `order` is provided, the slice is taken in `order`. Defaults to None.
+        """
         if start < 0 or finish > len(dataset):
             raise ValueError("subset overruns the dataset.")
         self._dataset = dataset
@@ -168,6 +213,12 @@ class SliceDataset(DatasetMixin):
 
 class SubsetDataset(DatasetMixin):
     def __init__(self, dataset, indices):
+        """A Dataset which is a subset of the base dataset.
+
+        Args:
+            dataset (DatasetMixin): the base dataset.
+            indices (Iterable[int]): the indices of the examples to pick.
+        """
         self._dataset = dataset
         if len(indices) > len(dataset):
             raise ValueError("subset's size larger that dataset's size!")
@@ -184,6 +235,12 @@ class SubsetDataset(DatasetMixin):
 
 class FilterDataset(DatasetMixin):
     def __init__(self, dataset, filter_fn):
+        """A filtered dataset.
+
+        Args:
+            dataset (DatasetMixin): the base dataset.
+            filter_fn (callable): a callable which takes an example of the base dataset and return a boolean.
+        """
         self._dataset = dataset
         self._indices = [
             i for i in range(len(dataset)) if filter_fn(dataset[i])
@@ -200,6 +257,11 @@ class FilterDataset(DatasetMixin):
 
 class ChainDataset(DatasetMixin):
     def __init__(self, *datasets):
+        """A concatenation of the several datasets which the same structure.
+
+        Args:
+            datasets (Iterable[DatasetMixin]): datasets to concat.
+        """
         self._datasets = datasets
 
     def __len__(self):

parakeet/data/sampler.py

@@ -14,7 +14,7 @@
 """
 At most cases, we have non-stream dataset, which means we can random access it with __getitem__, and we can get the length of the dataset with __len__.
 
-This suffices for a sampler. We implemente sampler as iterable of valid indices. By valid, we mean 0 <= index < N, where N is the length of the dataset. We then collect several indices within a batch and use it to collect examples from the dataset with __getitem__. Then collate this examples to form a batch.
+This suffices for a sampler. We implemente sampler as iterable of valid indices. By valid, we mean 0 <= index < N, where N is the length of the dataset. We then collect several indices within a batch and use them to collect examples from the dataset with __getitem__. Then transform these examples into a batch.
 
 So the sampler is only responsible for generating valid indices.
 """
@@ -24,9 +24,6 @@ import random
 
 
 class Sampler(object):
-    def __init__(self, data_source):
-        pass
-
     def __iter__(self):
         # return a iterator of indices
         # or a iterator of list[int], for BatchSampler
@@ -35,6 +32,11 @@ class Sampler(object):
 
 class SequentialSampler(Sampler):
     def __init__(self, data_source):
+        """Sequential sampler, the simplest sampler that samples indices from 0 to N - 1, where N is the dataset is length.
+
+        Args:
+            data_source (DatasetMixin): the dataset. This is used to get the dataset's length.
+        """
         self.data_source = data_source
 
     def __iter__(self):
@@ -46,6 +48,13 @@ class SequentialSampler(Sampler):
 
 class RandomSampler(Sampler):
     def __init__(self, data_source, replacement=False, num_samples=None):
+        """Random sampler.
+
+        Args:
+            data_source (DatasetMixin): the dataset. This is used to get the dataset's length.
+            replacement (bool, optional): whether replacement is enabled in sampling. When `replacement` is True, `num_samples` must be provided. Defaults to False.
+            num_samples (int, optional): numbers of indices to draw. This option should only be provided when replacement is True. Defaults to None.
+        """
         self.data_source = data_source
         self.replacement = replacement
         self._num_samples = num_samples
@@ -66,7 +75,6 @@ class RandomSampler(Sampler):
 
     @property
     def num_samples(self):
-        # dataset size might change at runtime
         if self._num_samples is None:
             return len(self.data_source)
         return self._num_samples
@@ -84,12 +92,16 @@ class RandomSampler(Sampler):
 
 
 class SubsetRandomSampler(Sampler):
-    r"""Samples elements randomly from a given list of indices, without replacement.
+    """Samples elements randomly from a given list of indices, without replacement.
     Arguments:
         indices (sequence): a sequence of indices
     """
 
     def __init__(self, indices):
+        """
+        Args:
+            indices (List[int]): indices to sample from.
+        """
         self.indices = indices
 
     def __iter__(self):
@@ -112,6 +124,14 @@ class PartialyRandomizedSimilarTimeLengthSampler(Sampler):
                  batch_size=4,
                  batch_group_size=None,
                  permutate=True):
+        """[summary]
+
+        Args:
+            lengths (List[int]): The length of the examples of the dataset. This is the key to be considered as 'time length'.
+            batch_size (int, optional): batch size. Defaults to 4.
+            batch_group_size (int, optional): the size of a small batch. Random shuffling is applied within such patches. If `batch_group_size` is not provided, it is set to min(batch_size * 32, len(self.lengths)). Batch_group_size should be perfectly divided by batch_size. Defaults to None.
+            permutate (bool, optional): permutate batches. Defaults to True.
+        """
         _lengths = np.array(
             lengths,
             dtype=np.int64)  # maybe better implement length as a sort key
@@ -157,13 +177,11 @@ class PartialyRandomizedSimilarTimeLengthSampler(Sampler):
 
 
 class WeightedRandomSampler(Sampler):
-    r"""Samples elements from ``[0,..,len(weights)-1]`` with given probabilities (weights).
+    """Samples elements from ``[0,..,len(weights)-1]`` with given probabilities (weights).
     Args:
-        weights (sequence)   : a sequence of weights, not necessary summing up to one
-        num_samples (int): number of samples to draw
-        replacement (bool): if ``True``, samples are drawn with replacement.
-            If not, they are drawn without replacement, which means that when a
-            sample index is drawn for a row, it cannot be drawn again for that row.
+        weights (List[float]): a sequence of weights, not necessary summing up to 1.
+        num_samples (int): number of samples to draw.
+        replacement (bool): whether samples are drawn with replacement. When replacement is False, num_samples should not be larger than len(weights).
     Example:
         >>> list(WeightedRandomSampler([0.1, 0.9, 0.4, 0.7, 3.0, 0.6], 5, replacement=True))
         [0, 0, 0, 1, 0]
@@ -179,6 +197,10 @@ class WeightedRandomSampler(Sampler):
         self.weights = np.array(weights, dtype=np.float64)
         self.num_samples = num_samples
         self.replacement = replacement
+        if replacement is False and num_samples > len(weights):
+            raise ValueError(
+                "when replacement is False, num_samples should not be"
+                "larger that length of weight.")
 
     def __iter__(self):
         return iter(
@@ -194,6 +216,21 @@ class WeightedRandomSampler(Sampler):
 
 class DistributedSampler(Sampler):
     def __init__(self, dataset_size, num_trainers, rank, shuffle=True):
+        """Sampler used for data parallel training. Indices are divided into num_trainers parts. Each trainer gets a subset and iter that subset. If the dataset has 16 examples, and there are 4 trainers. 
+
+        Trainer 0 gets [0, 4, 8, 12];
+        Trainer 1 gets [1, 5, 9, 13];
+        Trainer 2 gets [2, 6, 10, 14];
+        trainer 3 gets [3, 7, 11, 15].
+
+        It ensures that trainer get different parts of the dataset. If dataset's length cannot be perfectly devidef by num_trainers, some examples appended to the dataset, to ensures that every trainer gets the same amounts of examples.
+
+        Args:
+            dataset_size (int): the length of the dataset.
+            num_trainers (int): number of trainers(training processes).
+            rank (int): local rank of the trainer.
+            shuffle (bool, optional): whether to shuffle the indices before iteration. Defaults to True.
+        """
         self.dataset_size = dataset_size
         self.num_trainers = num_trainers
         self.rank = rank
@@ -222,20 +259,20 @@ class DistributedSampler(Sampler):
 
 
 class BatchSampler(Sampler):
-    r"""Wraps another sampler to yield a mini-batch of indices.
-    Args:
-        sampler (Sampler): Base sampler.
-        batch_size (int): Size of mini-batch.
-        drop_last (bool): If ``True``, the sampler will drop the last batch if
-            its size would be less than ``batch_size``
-    Example:
-        >>> list(BatchSampler(SequentialSampler(range(10)), batch_size=3, drop_last=False))
-        [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9]]
-        >>> list(BatchSampler(SequentialSampler(range(10)), batch_size=3, drop_last=True))
-        [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
-    """
+    """Wraps another sampler to yield a mini-batch of indices."""
 
     def __init__(self, sampler, batch_size, drop_last):
+        """
+        Args:
+            sampler (Sampler): Base sampler.
+            batch_size (int): Size of mini-batch.
+            drop_last (bool): If True, the sampler will drop the last batch if its size is less than batch_size.
+        Example:
+            >>> list(BatchSampler(SequentialSampler(range(10)), batch_size=3, drop_last=False))
+            [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9]]
+            >>> list(BatchSampler(SequentialSampler(range(10)), batch_size=3, drop_last=True))
+            [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
+        """
         if not isinstance(sampler, Sampler):
             raise ValueError("sampler should be an instance of "
                              "Sampler, but got sampler={}".format(sampler))

parakeet/models/clarinet/net.py

@@ -37,28 +37,41 @@ class Clarinet(dg.Layer):
                  stft,
                  min_log_scale=-6.0,
                  lmd=4.0):
+        """Clarinet model.
+
+        Args:
+            encoder (UpsampleNet): an UpsampleNet to upsample mel spectrogram.
+            teacher (WaveNet): a WaveNet, the teacher.
+            student (ParallelWaveNet): a ParallelWaveNet model, the student.
+            stft (STFT): a STFT model to perform differentiable stft transform.
+            min_log_scale (float, optional): used only for computing loss, the minimal value of log standard deviation of the output distribution of both the teacher and the student . Defaults to -6.0.
+            lmd (float, optional): weight for stft loss. Defaults to 4.0.
+        """
         super(Clarinet, self).__init__()
-        self.lmd = lmd
         self.encoder = encoder
         self.teacher = teacher
         self.student = student
+        self.stft = stft
 
+        self.lmd = lmd
         self.min_log_scale = min_log_scale
-        self.stft = stft
 
     def forward(self, audio, mel, audio_start, clip_kl=True):
-        """Compute loss for a distill model
-        
-        Arguments:
-            audio {Variable} -- shape(batch_size, time_steps), target waveform.
-            mel {Variable} -- shape(batch_size, condition_dim, time_steps // hop_length), original mel spectrogram, not upsampled yet.
-            audio_starts {Variable} -- shape(batch_size, ), the index of the start sample.
-            clip_kl (bool) -- whether to clip kl divergence if it is greater than 10.0.
-        
+        """Compute loss of Clarinet model.
+
+        Args:
+            audio (Variable): shape(B, T_audio), dtype: float, ground truth waveform.
+            mel (Variable): shape(B, F, T_mel), dtype: float, condition(mel spectrogram here).
+            audio_start (Variable): shape(B, ), dtype: int64, audio starts positions.
+            clip_kl (bool, optional): whether to clip kl_loss by maximum=100. Defaults to True.
+
         Returns:
-            Variable -- shape(1,), loss
+            Dict(str, Variable)
+            loss (Variable): shape(1, ), dtype: float, total loss.
+            kl (Variable): shape(1, ), dtype: float, kl divergence between the teacher's output distribution and student's output distribution.
+            regularization (Variable): shape(1, ), dtype: float, a regularization term of the KL divergence.
+            spectrogram_frame_loss (Variable): shape(1, ), dytpe: float, stft loss, the L1-distance of the magnitudes of the spectrograms of the ground truth waveform and synthesized waveform.
         """
-
         batch_size, audio_length = audio.shape  # audio clip's length
 
         z = F.gaussian_random(audio.shape)
@@ -104,13 +117,13 @@ class Clarinet(dg.Layer):
 
     @dg.no_grad
     def synthesis(self, mel):
-        """Synthesize waveform conditioned on the mel spectrogram.
-        
-        Arguments:
-            mel {Variable} -- shape(batch_size, frequqncy_bands, frames)
-        
+        """Synthesize waveform using the encoder and the student network.
+
+        Args:
+            mel (Variable): shape(B, F, T_mel), the condition(mel spectrogram here).
+
         Returns:
-            Variable -- shape(batch_size, frames * upsample_factor)
+            Variable: shape(B, T_audio), the synthesized waveform. (T_audio = T_mel * upscale_factor, where upscale_factor is the `upscale_factor` of the encoder.)
         """
         condition = self.encoder(mel)
         samples_shape = (condition.shape[0], condition.shape[-1])
@@ -121,6 +134,14 @@ class Clarinet(dg.Layer):
 
 class STFT(dg.Layer):
     def __init__(self, n_fft, hop_length, win_length, window="hanning"):
+        """A module for computing differentiable stft transform. See `librosa.stft` for more details.
+
+        Args:
+            n_fft (int): number of samples in a frame.
+            hop_length (int): number of samples shifted between adjacent frames.
+            win_length (int): length of the window function.
+            window (str, optional): name of window function, see `scipy.signal.get_window` for more details. Defaults to "hanning".
+        """
         super(STFT, self).__init__()
         self.hop_length = hop_length
         self.n_bin = 1 + n_fft // 2
@@ -146,6 +167,16 @@ class STFT(dg.Layer):
         self.weight = dg.to_variable(w)
 
     def forward(self, x):
+        """Compute the stft transform.
+
+        Args:
+            x (Variable): shape(B, T), dtype: float, the input waveform.
+
+        Returns:
+            (real, imag)
+            real (Variable): shape(B, C, 1, T), dtype: float, the real part of the spectrogram. (C = 1 + n_fft // 2)
+            imag (Variable): shape(B, C, 1, T), dtype: float, the image part of the spectrogram. (C = 1 + n_fft // 2) 
+        """
         # x(batch_size, time_steps)
         # pad it first with reflect mode
         pad_start = F.reverse(x[:, 1:1 + self.n_fft // 2], axis=1)
@@ -159,11 +190,31 @@ class STFT(dg.Layer):
         return real, imag
 
     def power(self, x):
+        """Compute the power spectrogram.
+
+        Args:
+            (real, imag)
+            real (Variable): shape(B, C, 1, T), dtype: float, the real part of the spectrogram.
+            imag (Variable): shape(B, C, 1, T), dtype: float, the image part of the spectrogram.
+
+        Returns:
+            Variable: shape(B, C, 1, T), dtype: float, the power spectrogram.
+        """
         real, imag = self(x)
         power = real**2 + imag**2
         return power
 
     def magnitude(self, x):
+        """Compute the magnitude spectrogram.
+
+        Args:
+            (real, imag)
+            real (Variable): shape(B, C, 1, T), dtype: float, the real part of the spectrogram.
+            imag (Variable): shape(B, C, 1, T), dtype: float, the image part of the spectrogram.
+
+        Returns:
+            Variable: shape(B, C, 1, T), dtype: float, the magnitude spectrogram. It is the square root of the power spectrogram.
+        """
         power = self.power(x)
         magnitude = F.sqrt(power)
         return magnitude

parakeet/models/clarinet/parallel_wavenet.py

@@ -29,6 +29,15 @@ from parakeet.models.wavenet import WaveNet
 class ParallelWaveNet(dg.Layer):
     def __init__(self, n_loops, n_layers, residual_channels, condition_dim,
                  filter_size):
+        """ParallelWaveNet, an inverse autoregressive flow model, it contains several flows(WaveNets).
+
+        Args:
+            n_loops (List[int]): `n_loop` for each flow.
+            n_layers (List[int]): `n_layer` for each flow.
+            residual_channels (int): `residual_channels` for every flow.
+            condition_dim (int): `condition_dim` for every flow.
+            filter_size (int): `filter_size` for every flow.
+        """
         super(ParallelWaveNet, self).__init__()
         self.flows = dg.LayerList()
         for n_loop, n_layer in zip(n_loops, n_layers):
@@ -38,20 +47,18 @@ class ParallelWaveNet(dg.Layer):
                         filter_size, "mog", -100.0))
 
     def forward(self, z, condition=None):
-        """Inverse Autoregressive Flow. Several wavenets.
-        
-        Arguments:
-            z {Variable} -- shape(batch_size, time_steps), hidden variable, sampled from a standard normal distribution.
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim, time_steps), condition, basically upsampled mel spectrogram. (default: {None})
-        
+        """Transform a random noise sampled from a standard Gaussian distribution into sample from the target distribution. And output the mean and log standard deviation of the output distribution.
+
+        Args:
+            z (Variable): shape(B, T), random noise sampled from a standard gaussian disribution.
+            condition (Variable, optional): shape(B, F, T), dtype: float, the upsampled condition. Defaults to None.
+
         Returns:
-            Variable -- shape(batch_size, time_steps), transformed z.
-            Variable -- shape(batch_size, time_steps), output distribution's mu.
-            Variable -- shape(batch_size, time_steps), output distribution's log_std.
+            (z, out_mu, out_log_std)
+            z (Variable): shape(B, T), dtype: float, transformed noise, it is the synthesized waveform.
+            out_mu (Variable): shape(B, T), dtype: float, means of the output distributions.
+            out_log_std (Variable): shape(B, T), dtype: float, log standard deviations of the output distributions.
         """
-
         for i, flow in enumerate(self.flows):
             theta = flow(z, condition)  # w, mu, log_std [0: T]
             w, mu, log_std = F.split(theta, 3, dim=-1)  # (B, T, 1) for each

parakeet/models/deepvoice3/attention.py

@@ -31,6 +31,16 @@ class Attention(dg.Layer):
                  window_range=WindowRange(-1, 3),
                  key_projection=True,
                  value_projection=True):
+        """Attention Layer for Deep Voice 3.
+
+        Args:
+            query_dim (int): the dimension of query vectors. (The size of a single vector of query.)
+            embed_dim (int): the dimension of keys and values.
+            dropout (float, optional): dropout probability of attention. Defaults to 0.0.
+            window_range (WindowRange, optional): range of attention, this is only used at inference. Defaults to WindowRange(-1, 3).
+            key_projection (bool, optional): whether the `Attention` Layer has a Linear Layer for the keys to pass through before computing attention. Defaults to True.
+            value_projection (bool, optional): whether the `Attention` Layer has a Linear Layer for the values to pass through before computing attention. Defaults to True.
+        """
         super(Attention, self).__init__()
         std = np.sqrt(1 / query_dim)
         self.query_proj = Linear(
@@ -54,29 +64,19 @@ class Attention(dg.Layer):
 
     def forward(self, query, encoder_out, mask=None, last_attended=None):
         """
-        Compute pooled context representation and alignment scores.
+        Compute contextualized representation and alignment scores.
         
         Args:
-            query (Variable): shape(B, T_dec, C_q), the query tensor,
-                where C_q means the channel of query.
-            encoder_out (Tuple(Variable, Variable)): 
-                keys (Variable): shape(B, T_enc, C_emb), the key
-                    representation from an encoder, where C_emb means
-                    text embedding size.
-                values (Variable): shape(B, T_enc, C_emb), the value
-                    representation from an encoder, where C_emb means
-                    text embedding size.
-            mask (Variable, optional): Shape(B, T_enc), mask generated with 
-                valid text lengths.
-            last_attended (int, optional): The position that received most
-                attention at last timestep. This is only used at decoding.
+            query (Variable): shape(B, T_dec, C_q), dtype: float, the query tensor, where C_q means the query dim.
+            encoder_out (keys, values): 
+                keys (Variable): shape(B, T_enc, C_emb), dtype: float, the key representation from an encoder, where C_emb means embed dim.
+                values (Variable): shape(B, T_enc, C_emb), dtype: float, the value representation from an encoder, where C_emb means embed dim.
+            mask (Variable, optional): shape(B, T_enc), dtype: float, mask generated with valid text lengths. Pad tokens corresponds to 1, and valid tokens correspond to 0.
+            last_attended (int, optional): The position that received the most attention at last time step. This is only used at inference.
 
         Outpus:
-            x (Variable): Shape(B, T_dec, C_q), the context representation
-                pooled from attention mechanism.
-            attn_scores (Variable): shape(B, T_dec, T_enc), the alignment
-                tensor, where T_dec means the number of decoder time steps and 
-                T_enc means number the number of decoder time steps.
+            x (Variable): shape(B, T_dec, C_q), dtype: float, the contextualized representation from attention mechanism.
+            attn_scores (Variable): shape(B, T_dec, T_enc), dtype: float, the alignment tensor, where T_dec means the number of decoder time steps and T_enc means number the number of decoder time steps.
         """
         keys, values = encoder_out
         residual = query
@@ -85,7 +85,6 @@ class Attention(dg.Layer):
         if self.key_projection:
             keys = self.key_proj(keys)
         x = self.query_proj(query)
-        # TODO: check the code
 
         x = F.matmul(x, keys, transpose_y=True)
 
@@ -97,7 +96,6 @@ class Attention(dg.Layer):
 
         # if last_attended is provided, focus only on a window range around it
         # to enforce monotonic attention.
-        # TODO: if last attended is a shape(B,) array
         if last_attended is not None:
             locality_mask = np.ones(shape=x.shape, dtype=np.float32)
             backward, ahead = self.window_range
@@ -116,7 +114,7 @@ class Attention(dg.Layer):
             x, self.dropout, dropout_implementation="upscale_in_train")
         x = F.matmul(x, values)
         encoder_length = keys.shape[1]
-        # CAUTION: is it wrong? let it be now
+
         x = F.scale(x, encoder_length * np.sqrt(1.0 / encoder_length))
         x = self.out_proj(x)
         x = F.scale((x + residual), np.sqrt(0.5))

parakeet/models/deepvoice3/conv1dglu.py

@@ -24,10 +24,7 @@ from parakeet.modules.weight_norm import Conv1D, Conv1DCell, Conv2D, Linear
 
 class Conv1DGLU(dg.Layer):
     """
-    A Convolution 1D block with GLU activation. It also applys dropout for the 
-    input x. It fuses speaker embeddings through a FC activated by softsign. It
-    has residual connection from the input x, and scale the output by 
-    np.sqrt(0.5).
+    A Convolution 1D block with GLU activation. It also applys dropout for the input x. It integrates speaker embeddings through a Linear activated by softsign. It has residual connection from the input x, and scale the output by np.sqrt(0.5).
     """
 
     def __init__(self,
@@ -41,8 +38,21 @@ class Conv1DGLU(dg.Layer):
                  dropout=0.0,
                  causal=False,
                  residual=True):
-        super(Conv1DGLU, self).__init__()
+        """[summary]
 
+        Args:
+            n_speakers (int): number of speakers.
+            speaker_dim (int): speaker embedding's size.
+            in_channels (int): channels of the input.
+            num_filters (int): channels of the output.
+            filter_size (int, optional): filter size of the internal Conv1DCell. Defaults to 1.
+            dilation (int, optional): dilation of the internal Conv1DCell. Defaults to 1.
+            std_mul (float, optional): [description]. Defaults to 4.0.
+            dropout (float, optional): dropout probability. Defaults to 0.0.
+            causal (bool, optional): padding of the Conv1DCell. It shoudl be True if `add_input` method of `Conv1DCell` is ever used. Defaults to False.
+            residual (bool, optional): whether to use residual connection. If True, in_channels shoudl equals num_filters. Defaults to True.
+        """
+        super(Conv1DGLU, self).__init__()
         # conv spec
         self.in_channels = in_channels
         self.n_speakers = n_speakers
@@ -83,18 +93,12 @@ class Conv1DGLU(dg.Layer):
     def forward(self, x, speaker_embed=None):
         """
         Args:
-            x (Variable): Shape(B, C_in, T), the input of Conv1DGLU
-                layer, where B means batch_size, C_in means the input channels
-                T means input time steps.
-            speaker_embed_bct1 (Variable): Shape(B, C_sp), expanded
-                speaker embed, where C_sp means speaker embedding size. Note
-                that when using residual connection, the Conv1DGLU does not
-                change the number of channels, so out channels equals input
-                channels.
+            x (Variable): shape(B, C_in, T), dtype: float, the input of Conv1DGLU layer, where B means batch_size, C_in means the input channels T means input time steps.
+            speaker_embed (Variable): shape(B, C_sp), dtype: float, speaker embed, where C_sp means speaker embedding size.
 
         Returns:
-            x (Variable): Shape(B, C_out, T), the output of Conv1DGLU, where
-                C_out means the output channels of Conv1DGLU.
+            x (Variable): shape(B, C_out, T), the output of Conv1DGLU, where
+                C_out means the `num_filters`.
         """
         residual = x
         x = F.dropout(
@@ -114,22 +118,20 @@ class Conv1DGLU(dg.Layer):
         return x
 
     def start_sequence(self):
+        """Prepare the Conv1DGLU to generate a new sequence. This method should be called before starting calling `add_input` multiple times.
+        """
         self.conv.start_sequence()
 
     def add_input(self, x_t, speaker_embed=None):
         """
+        Takes a step of inputs and return a step of outputs. It works similarily with the `forward` method, but in a `step-in-step-out` fashion.
+
         Args:
-            x (Variable): Shape(B, C_in), the input of Conv1DGLU
-                layer, where B means batch_size, C_in means the input channels.
-            speaker_embed_bct1 (Variable): Shape(B, C_sp), expanded
-                speaker embed, where C_sp means speaker embedding size. Note
-                that when using residual connection, the Conv1DGLU does not
-                change the number of channels, so out channels equals input
-                channels.
+            x_t (Variable): shape(B, C_in, T=1), dtype: float, the input of Conv1DGLU layer, where B means batch_size, C_in means the input channels.
+            speaker_embed (Variable): Shape(B, C_sp), dtype: float, speaker embed, where C_sp means speaker embedding size. 
 
         Returns:
-            x (Variable): Shape(B, C_out), the output of Conv1DGLU, where
-                C_out means the output channels of Conv1DGLU.
+            x (Variable): shape(B, C_out), the output of Conv1DGLU, where C_out means the `num_filter`.
         """
         residual = x_t
         x_t = F.dropout(

parakeet/models/deepvoice3/converter.py

@@ -25,6 +25,17 @@ from parakeet.models.deepvoice3.encoder import ConvSpec
 
 
 def upsampling_4x_blocks(n_speakers, speaker_dim, target_channels, dropout):
+    """Return a list of Layers that upsamples the input by 4 times in time dimension.
+
+    Args:
+        n_speakers (int): number of speakers of the Conv1DGLU layers used.
+        speaker_dim (int): speaker embedding size of the Conv1DGLU layers used.
+        target_channels (int): channels of the input and the output.(the list of layers does not change the number of channels.)
+        dropout (float): dropout probability.
+
+    Returns:
+        List[Layer]: upsampling layers.
+    """
     # upsampling convolitions
     upsampling_convolutions = [
         Conv1DTranspose(
@@ -41,42 +52,56 @@ def upsampling_4x_blocks(n_speakers, speaker_dim, target_channels, dropout):
             3,
             dilation=1,
             std_mul=1.,
-            dropout=dropout), Conv1DGLU(
-                n_speakers,
-                speaker_dim,
-                target_channels,
-                target_channels,
-                3,
-                dilation=3,
-                std_mul=4.,
-                dropout=dropout), Conv1DTranspose(
-                    target_channels,
-                    target_channels,
-                    2,
-                    stride=2,
-                    param_attr=I.Normal(scale=np.sqrt(
-                        4. / (2 * target_channels)))), Conv1DGLU(
-                            n_speakers,
-                            speaker_dim,
-                            target_channels,
-                            target_channels,
-                            3,
-                            dilation=1,
-                            std_mul=1.,
-                            dropout=dropout), Conv1DGLU(
-                                n_speakers,
-                                speaker_dim,
-                                target_channels,
-                                target_channels,
-                                3,
-                                dilation=3,
-                                std_mul=4.,
-                                dropout=dropout)
+            dropout=dropout),
+        Conv1DGLU(
+            n_speakers,
+            speaker_dim,
+            target_channels,
+            target_channels,
+            3,
+            dilation=3,
+            std_mul=4.,
+            dropout=dropout),
+        Conv1DTranspose(
+            target_channels,
+            target_channels,
+            2,
+            stride=2,
+            param_attr=I.Normal(scale=np.sqrt(4. / (2 * target_channels)))),
+        Conv1DGLU(
+            n_speakers,
+            speaker_dim,
+            target_channels,
+            target_channels,
+            3,
+            dilation=1,
+            std_mul=1.,
+            dropout=dropout),
+        Conv1DGLU(
+            n_speakers,
+            speaker_dim,
+            target_channels,
+            target_channels,
+            3,
+            dilation=3,
+            std_mul=4.,
+            dropout=dropout),
     ]
     return upsampling_convolutions
 
 
 def upsampling_2x_blocks(n_speakers, speaker_dim, target_channels, dropout):
+    """Return a list of Layers that upsamples the input by 2 times in time dimension.
+
+    Args:
+        n_speakers (int): number of speakers of the Conv1DGLU layers used.
+        speaker_dim (int): speaker embedding size of the Conv1DGLU layers used.
+        target_channels (int): channels of the input and the output.(the list of layers does not change the number of channels.)
+        dropout (float): dropout probability.
+
+    Returns:
+        List[Layer]: upsampling layers.
+    """
     upsampling_convolutions = [
         Conv1DTranspose(
             target_channels,
@@ -106,6 +131,17 @@ def upsampling_2x_blocks(n_speakers, speaker_dim, target_channels, dropout):
 
 
 def upsampling_1x_blocks(n_speakers, speaker_dim, target_channels, dropout):
+    """Return a list of Layers that upsamples the input by 1 times in time dimension.
+
+    Args:
+        n_speakers (int): number of speakers of the Conv1DGLU layers used.
+        speaker_dim (int): speaker embedding size of the Conv1DGLU layers used.
+        target_channels (int): channels of the input and the output.(the list of layers does not change the number of channels.)
+        dropout (float): dropout probability.
+
+    Returns:
+        List[Layer]: upsampling layers.
+    """
     upsampling_convolutions = [
         Conv1DGLU(
             n_speakers,
@@ -121,10 +157,7 @@ def upsampling_1x_blocks(n_speakers, speaker_dim, target_channels, dropout):
 
 
 class Converter(dg.Layer):
-    """
-    Vocoder that transforms mel spectrogram (or ecoder hidden states) 
-    to waveform.
-    """
+    """Vocoder that transforms mel spectrogram (or ecoder hidden states) to waveform."""
 
     def __init__(self,
                  n_speakers,
@@ -134,6 +167,17 @@ class Converter(dg.Layer):
                  convolutions=(ConvSpec(256, 5, 1), ) * 4,
                  time_upsampling=1,
                  dropout=0.0):
+        """[summary]
+
+        Args:
+            n_speakers (int): number of speakers.
+            speaker_dim (int): speaker embedding size.
+            in_channels (int): channels of the input.
+            linear_dim (int): channels of the linear spectrogram.
+            convolutions (Iterable[ConvSpec], optional): specifications of the internal convolutional layers. ConvSpec is a namedtuple of (output_channels, filter_size, dilation) Defaults to (ConvSpec(256, 5, 1), )*4.
+            time_upsampling (int, optional): time upsampling factor of the converter, possible options are {1, 2, 4}. Note that this should equals the downsample factor of the mel spectrogram. Defaults to 1.
+            dropout (float, optional): dropout probability. Defaults to 0.0.
+        """
         super(Converter, self).__init__()
 
         self.n_speakers = n_speakers
@@ -215,23 +259,12 @@ class Converter(dg.Layer):
         Convert mel spectrogram or decoder hidden states to linear spectrogram.
         
         Args:
-            x (Variable): Shape(B, T_mel, C_in), converter inputs, where
-                C_in means the input channel for the converter. Note that it 
-                can be either C_mel (channel of mel spectrogram) or C_dec // r.
-                When use mel_spectrogram as the input of converter, C_in = 
-                C_mel; and when use decoder states as the input of converter,
-                C_in = C_dec // r. In this scenario, decoder hidden states are
-                treated as if they were r outputs per decoder step and are
-                unpacked before passing to the converter.
-            speaker_embed (Variable, optional): shape(B, C_sp), speaker
-                embedding, where C_sp means the speaker embedding size.
+            x (Variable): Shape(B, T_mel, C_in), dtype: float, converter inputs, where C_in means the input channel for the converter. Note that it can be either C_mel (channel of mel spectrogram) or C_dec // r.
+                When use mel_spectrogram as the input of converter, C_in = C_mel; and when use decoder states as the input of converter, C_in = C_dec // r.
+            speaker_embed (Variable, optional): shape(B, C_sp), dtype: float, speaker embedding, where C_sp means the speaker embedding size.
 
         Returns:
-            out (Variable): Shape(B, T_lin, C_lin), the output linear 
-                spectrogram, where C_lin means the channel of linear 
-                spectrogram and T_linear means the length(time steps) of linear
-                spectrogram. T_line = time_upsampling * T_mel, which depends 
-                on the time_upsampling converter.
+            out (Variable): Shape(B, T_lin, C_lin), the output linear spectrogram, where C_lin means the channel of linear spectrogram and T_linear means the length(time steps) of linear spectrogram. T_line = time_upsampling * T_mel, which depends on the time_upsampling of the converter.
         """
         x = F.transpose(x, [0, 2, 1])
         x = self.first_conv_proj(x)

parakeet/models/deepvoice3/decoder.py

@@ -36,15 +36,12 @@ def gen_mask(valid_lengths, max_len, dtype="float32"):
      [0, 0, 0, 0, 0, 0, 0]].
 
     Args:
-        valid_lengths (Variable): Shape(B), dtype: int64. A 1D-Tensor containing
-            the valid lengths (timesteps) of each example, where B means
-            beatch_size.
-        max_len (int): The length (number of timesteps) of the mask.
-        dtype (str, optional): A string that specifies the data type of the
-            returned mask.
+        valid_lengths (Variable): shape(B, ), dtype: int64. A rank-1 Tensor containing the valid lengths (timesteps) of each example, where B means beatch_size.
+        max_len (int): The length (number of time steps) of the mask.
+        dtype (str, optional): A string that specifies the data type of the returned mask. Defaults to 'float32'.
 
     Returns:
-        mask (Variable): A mask computed from valid lengths.
+        mask (Variable): shape(B, max_len), dtype: float, a mask computed from valid lengths.
     """
     mask = F.sequence_mask(valid_lengths, maxlen=max_len, dtype=dtype)
     mask = 1 - mask
@@ -54,14 +51,13 @@ def gen_mask(valid_lengths, max_len, dtype="float32"):
 def fold_adjacent_frames(frames, r):
     """fold multiple adjacent frames.
     
-    Arguments:
-        frames {Variable} -- shape(batch_size, time_steps, channels), the spectrogram
-        r {int} -- frames per step.
+    Args:
+        frames (Variable): shape(B, T, C), the spectrogram.
+        r (int): frames per step.
     
     Returns:
-        Variable -- shape(batch_size, time_steps // r, r *channels), folded frames
+        Variable: shape(B, T // r, r * C), folded frames.
     """
-
     if r == 1:
         return frames
     batch_size, time_steps, channels = frames.shape
@@ -75,16 +71,15 @@ def fold_adjacent_frames(frames, r):
 
 
 def unfold_adjacent_frames(folded_frames, r):
-    """fold multiple adjacent frames.
+    """unfold the folded frames.
     
-    Arguments:
-        folded_frames {Variable} -- shape(batch_size, time_steps // r, r * channels), the spectrogram
-        r {int} -- frames per step.
+    Args:
+        folded_frames (Variable): shape(B, T, C), the folded spectrogram.
+        r (int): frames per step.
     
     Returns:
-        Variable -- shape(batch_size, time_steps, channels), folded frames
+        Variable: shape(B, T * r, C // r), unfolded frames.
     """
-
     if r == 1:
         return folded_frames
     batch_size, time_steps, channels = folded_frames.shape
@@ -93,26 +88,44 @@ def unfold_adjacent_frames(folded_frames, r):
 
 
 class Decoder(dg.Layer):
-    def __init__(
-            self,
-            n_speakers,
-            speaker_dim,
-            embed_dim,
-            mel_dim,
-            r=1,
-            max_positions=512,
-            padding_idx=None,  # remove it!
-            preattention=(ConvSpec(128, 5, 1), ) * 4,
-            convolutions=(ConvSpec(128, 5, 1), ) * 4,
-            attention=True,
-            dropout=0.0,
-            use_memory_mask=False,
-            force_monotonic_attention=False,
-            query_position_rate=1.0,
-            key_position_rate=1.0,
-            window_range=WindowRange(-1, 3),
-            key_projection=True,
-            value_projection=True):
+    def __init__(self,
+                 n_speakers,
+                 speaker_dim,
+                 embed_dim,
+                 mel_dim,
+                 r=1,
+                 max_positions=512,
+                 preattention=(ConvSpec(128, 5, 1), ) * 4,
+                 convolutions=(ConvSpec(128, 5, 1), ) * 4,
+                 attention=True,
+                 dropout=0.0,
+                 use_memory_mask=False,
+                 force_monotonic_attention=False,
+                 query_position_rate=1.0,
+                 key_position_rate=1.0,
+                 window_range=WindowRange(-1, 3),
+                 key_projection=True,
+                 value_projection=True):
+        """Decoder of the Deep Voice 3 model.
+
+        Args:
+            n_speakers (int): number of speakers.
+            speaker_dim (int): speaker embedding size.
+            embed_dim (int): text embedding size.
+            mel_dim (int): channel of mel input.(mel bands)
+            r (int, optional): number of frames generated per decoder step. Defaults to 1.
+            max_positions (int, optional): max position for text and decoder steps. Defaults to 512.
+            convolutions (Iterable[ConvSpec], optional): specification of causal convolutional layers inside the decoder. ConvSpec is a namedtuple of output_channels, filter_size and dilation. Defaults to (ConvSpec(128, 5, 1), )*4.
+            attention (bool or List[bool], optional): whether to use attention, it should have the same length with `convolutions` if it is a list of bool, indicating whether to have an Attention layer coupled with the corresponding convolutional layer. If it is a bool, it is repeated len(convolutions) times internally. Defaults to True.
+            dropout (float, optional): dropout probability. Defaults to 0.0.
+            use_memory_mask (bool, optional): whether to use memory mask at the Attention layer. It should have the same length with `attention` if it is a list of bool, indicating whether to use memory mask at the corresponding Attention layer. If it is a bool, it is repeated len(attention) times internally. Defaults to False.
+            force_monotonic_attention (bool, optional): whether to use monotonic_attention at the Attention layer when inferencing. It should have the same length with `attention` if it is a list of bool, indicating whether to use monotonic_attention at the corresponding Attention layer. If it is a bool, it is repeated len(attention) times internally. Defaults to False.
+            query_position_rate (float, optional): position_rate of the PositionEmbedding for query. Defaults to 1.0.
+            key_position_rate (float, optional): position_rate of the PositionEmbedding for key. Defaults to 1.0.
+            window_range (WindowRange, optional): window range of monotonic attention. Defaults to WindowRange(-1, 3).
+            key_projection (bool, optional): `key_projection` of Attention layers. Defaults to True.
+            value_projection (bool, optional): `value_projection` of Attention layers Defaults to True.
+        """
         super(Decoder, self).__init__()
 
         self.dropout = dropout
@@ -125,10 +138,9 @@ class Decoder(dg.Layer):
 
         conv_channels = convolutions[0].out_channels
         # only when padding idx is 0 can we easilt handle it
-        self.embed_keys_positions = PositionEmbedding(
-            max_positions, embed_dim, padding_idx=0)
-        self.embed_query_positions = PositionEmbedding(
-            max_positions, conv_channels, padding_idx=0)
+        self.embed_keys_positions = PositionEmbedding(max_positions, embed_dim)
+        self.embed_query_positions = PositionEmbedding(max_positions,
+                                                       conv_channels)
 
         if n_speakers > 1:
             std = np.sqrt((1 - dropout) / speaker_dim)
@@ -248,41 +260,20 @@ class Decoder(dg.Layer):
         Compute decoder outputs with ground truth mel spectrogram.
 
         Args:
-            encoder_out (Tuple(Variable, Variable)): 
-                keys (Variable): shape(B, T_enc, C_emb), the key
-                    representation from an encoder, where C_emb means
-                    text embedding size.
-                values (Variable): shape(B, T_enc, C_emb), the value
-                    representation from an encoder, where C_emb means
-                    text embedding size.
-            lengths (Variable): shape(batch_size,), dtype: int64, valid lengths
-                of text inputs for each example.
-            inputs (Variable): shape(B, T_mel, C_mel), ground truth
-                mel-spectrogram, which is used as decoder inputs when training.
-            text_positions (Variable): shape(B, T_enc), dtype: int64.
-                Positions indices for text inputs for the encoder, where 
-                T_enc means the encoder timesteps.
-            frame_positions (Variable): shape(B, T_mel // r), dtype: 
-                int64. Positions indices for each decoder time steps.
-            speaker_embed: shape(batch_size, speaker_dim), speaker embedding, 
-                only used for multispeaker model.
-
+            encoder_out (keys, values): 
+                keys (Variable): shape(B, T_enc, C_emb), dtype: float, the key representation from an encoder, where C_emb means text embedding size.
+                values (Variable): shape(B, T_enc, C_emb), dtype: float, the value representation from an encoder, where C_emb means text embedding size.
+            lengths (Variable): shape(batch_size,), dtype: int64, valid lengths of text inputs for each example.
+            inputs (Variable): shape(B, T_mel, C_mel), ground truth mel-spectrogram, which is used as decoder inputs when training.
+            text_positions (Variable): shape(B, T_enc), dtype: int64. Positions indices for text inputs for the encoder, where T_enc means the encoder timesteps.
+            frame_positions (Variable): shape(B, T_mel // r), dtype: int64. Positions indices for each decoder time steps.
+            speaker_embed (Variable, optionals): shape(batch_size, speaker_dim), speaker embedding, only used for multispeaker model.
 
         Returns:
-            outputs (Variable): Shape(B, T_mel // r, r * C_mel). Decoder
-                outputs, where C_mel means the channels of mel-spectrogram, r 
-                means the outputs per decoder step, T_mel means the length(time
-                steps) of mel spectrogram. Note that, when r > 1, the decoder
-                outputs r frames of mel spectrogram per step.
-            alignments (Variable): Shape(N, B, T_mel // r, T_enc), the alignment
-                tensor between the decoder and the encoder, where N means number
-                of Attention Layers, T_mel means the length of mel spectrogram,
-                r means the outputs per decoder step, T_enc means the encoder
-                time steps.
-            done (Variable): Shape(B, T_mel // r), probability that the
-                outputs should stop.
-            decoder_states (Variable): Shape(B, T_mel // r, C_dec), decoder
-                hidden states, where C_dec means the channels of decoder states.
+            outputs (Variable): shape(B, T_mel, C_mel), dtype: float, decoder outputs, where C_mel means the channels of mel-spectrogram, T_mel means the length(time steps) of mel spectrogram. 
+            alignments (Variable): shape(N, B, T_mel // r, T_enc), dtype: float, the alignment tensor between the decoder and the encoder, where N means number of Attention Layers, T_mel means the length of mel spectrogram, r means the outputs per decoder step, T_enc means the encoder time steps.
+            done (Variable): shape(B, T_mel // r), dtype: float, probability that the last frame has been generated.
+            decoder_states (Variable): shape(B, T_mel, C_dec // r), ddtype: float, decoder hidden states, where C_dec means the channels of decoder states (the output channels of the last `convolutions`). Note that it should be perfectlt devided by `r`.
         """
         if speaker_embed is not None:
             speaker_embed = F.dropout(
@@ -366,6 +357,8 @@ class Decoder(dg.Layer):
         return r
 
     def start_sequence(self):
+        """Prepare the Decoder to decode. This method is called by `decode`.
+        """
         for layer in self.prenet:
             if isinstance(layer, Conv1DGLU):
                 layer.start_sequence()
@@ -379,6 +372,25 @@ class Decoder(dg.Layer):
                text_positions,
                speaker_embed=None,
                test_inputs=None):
+        """Decode from the encoder's output and other conditions.
+
+        Args:
+            encoder_out (keys, values): 
+                keys (Variable): shape(B, T_enc, C_emb), dtype: float, the key representation from an encoder, where C_emb means text embedding size.
+                values (Variable): shape(B, T_enc, C_emb), dtype: float, the value representation from an encoder, where C_emb means text embedding size.
+            text_positions (Variable): shape(B, T_enc), dtype: int64. Positions indices for text inputs for the encoder, where T_enc means the encoder timesteps.
+            speaker_embed (Variable, optional): shape(B, C_sp), speaker embedding, only used for multispeaker model.
+            test_inputs (Variable, optional): shape(B, T_test, C_mel). test input, it is only used for debugging. Defaults to None.
+
+        Returns:
+            outputs (Variable): shape(B, T_mel, C_mel), dtype: float, decoder outputs, where C_mel means the channels of mel-spectrogram, T_mel means the length(time steps) of mel spectrogram. 
+            alignments (Variable): shape(N, B, T_mel // r, T_enc), dtype: float, the alignment tensor between the decoder and the encoder, where N means number of Attention Layers, T_mel means the length of mel spectrogram, r means the outputs per decoder step, T_enc means the encoder time steps.
+            done (Variable): shape(B, T_mel // r), dtype: float, probability that the last frame has been generated. If the probability is larger than 0.5 at a step, the generation stops.
+            decoder_states (Variable): shape(B, T_mel, C_dec // r), ddtype: float, decoder hidden states, where C_dec means the channels of decoder states (the output channels of the last `convolutions`). Note that it should be perfectlt devided by `r`.
+
+        Note:
+            Only single instance inference is supported now, so B = 1.
+        """
         self.start_sequence()
         keys, values = encoder_out
         batch_size = keys.shape[0]

parakeet/models/deepvoice3/encoder.py

@@ -34,10 +34,20 @@ class Encoder(dg.Layer):
                  padding_idx=None,
                  embedding_weight_std=0.1,
                  convolutions=(ConvSpec(64, 5, 1), ) * 7,
-                 max_positions=512,
                  dropout=0.):
-        super(Encoder, self).__init__()
+        """[summary]
 
+        Args:
+            n_vocab (int): vocabulary size of the text embedding.
+            embed_dim (int): embedding size of the text embedding.
+            n_speakers (int): number of speakers.
+            speaker_dim (int): speaker embedding size.
+            padding_idx (int, optional): padding index of text embedding. Defaults to None.
+            embedding_weight_std (float, optional): standard deviation of the embedding weights when intialized. Defaults to 0.1.
+            convolutions (Iterable[ConvSpec], optional): specifications of the convolutional layers. ConvSpec is a namedtuple of output channels, filter_size and dilation. Defaults to (ConvSpec(64, 5, 1), )*7.
+            dropout (float, optional): dropout probability. Defaults to 0..
+        """
+        super(Encoder, self).__init__()
         self.embedding_weight_std = embedding_weight_std
         self.embed = dg.Embedding(
             (n_vocab, embed_dim),
@@ -101,18 +111,12 @@ class Encoder(dg.Layer):
         Encode text sequence.
         
         Args:
-            x (Variable): Shape(B, T_enc), dtype: int64. Ihe input text
-                indices. T_enc means the timesteps of decoder input x.
-            speaker_embed (Variable, optional): Shape(batch_size, speaker_dim),
-                dtype: float32. Speaker embeddings. This arg is not None only
-                when the model is a multispeaker model.
+            x (Variable): shape(B, T_enc), dtype: int64. Ihe input text indices. T_enc means the timesteps of decoder input x.
+            speaker_embed (Variable, optional): shape(B, C_sp), dtype: float, speaker embeddings. This arg is not None only when the model is a multispeaker model.
 
         Returns:
-            keys (Variable), Shape(B, T_enc, C_emb), the encoded
-                representation for keys, where C_emb menas the text embedding
-                size.
-            values (Variable), Shape(B, T_enc, C_emb), the encoded
-                representation for values.
+            keys (Variable), Shape(B, T_enc, C_emb), dtype: float, the encoded epresentation for keys, where C_emb menas the text embedding size.
+            values (Variable), Shape(B, T_enc, C_emb), dtype: float, the encoded representation for values.
         """
         x = self.embed(x)
         x = F.dropout(

parakeet/models/deepvoice3/loss.py

@@ -23,12 +23,10 @@ import paddle.fluid.dygraph as dg
 def masked_mean(inputs, mask):
     """
     Args:
-        inputs (Variable): Shape(B, T, C), the input, where B means
-            batch size, C means channels of input, T means timesteps of
-            the input.
-        mask (Variable): Shape(B, T), a mask. 
+        inputs (Variable): shape(B, T, C), dtype: float, the input.
+        mask (Variable): shape(B, T), dtype: float, a mask. 
     Returns:
-        loss (Variable): Shape(1, ), masked mean.
+        loss (Variable): shape(1, ), dtype: float, masked mean.
     """
     channels = inputs.shape[-1]
     masked_inputs = F.elementwise_mul(inputs, mask, axis=0)
@@ -38,6 +36,18 @@ def masked_mean(inputs, mask):
 
 @jit(nopython=True)
 def guided_attention(N, max_N, T, max_T, g):
+    """Generate an diagonal attention guide.
+    
+    Args:
+        N (int): valid length of encoder.
+        max_N (int): max length of encoder.
+        T (int): valid length of decoder.
+        max_T (int): max length of decoder.
+        g (float): sigma to adjust the degree of diagonal guide.
+
+    Returns:
+        np.ndarray: shape(max_N, max_T), dtype: float, the diagonal guide.
+    """
     W = np.zeros((max_N, max_T), dtype=np.float32)
     for n in range(N):
         for t in range(T):
@@ -47,6 +57,17 @@ def guided_attention(N, max_N, T, max_T, g):
 
 def guided_attentions(encoder_lengths, decoder_lengths, max_decoder_len,
                       g=0.2):
+    """Generate a diagonal attention guide for a batch.
+
+    Args:
+        encoder_lengths (np.ndarray): shape(B, ), dtype: int64, encoder valid lengths.
+        decoder_lengths (np.ndarray): shape(B, ), dtype: int64, decoder valid lengths.
+        max_decoder_len (int): max length of decoder.
+        g (float, optional): sigma to adjust the degree of diagonal guide.. Defaults to 0.2.
+
+    Returns:
+        np.ndarray: shape(B, max_T, max_N), dtype: float, the diagonal guide. (max_N: max encoder length, max_T: max decoder length.)
+    """
     B = len(encoder_lengths)
     max_input_len = encoder_lengths.max()
     W = np.zeros((B, max_decoder_len, max_input_len), dtype=np.float32)
@@ -65,6 +86,17 @@ class TTSLoss(object):
                  guided_attention_sigma=0.2,
                  downsample_factor=4,
                  r=1):
+        """Compute loss for Deep Voice 3 model.
+
+        Args:
+            masked_weight (float, optional): the weight of masked loss. Defaults to 0.0.
+            priority_bin ([type], optional): frequency bands for linear spectrogram loss to be prioritized. Defaults to None.
+            priority_weight (float, optional): weight for the prioritized frequency bands. Defaults to 0.0.
+            binary_divergence_weight (float, optional): weight for binary cross entropy (used for spectrogram loss). Defaults to 0.0.
+            guided_attention_sigma (float, optional): `sigma` for attention guide. Defaults to 0.2.
+            downsample_factor (int, optional): the downsample factor for mel spectrogram. Defaults to 4.
+            r (int, optional): frames per decoder step. Defaults to 1.
+        """
         self.masked_weight = masked_weight
         self.priority_bin = priority_bin  # only used for lin-spec loss
         self.priority_weight = priority_weight  # only used for lin-spec loss
@@ -76,6 +108,17 @@ class TTSLoss(object):
         self.downsample_factor = downsample_factor
 
     def l1_loss(self, prediction, target, mask, priority_bin=None):
+        """L1 loss for spectrogram.
+
+        Args:
+            prediction (Variable): shape(B, T, C), dtype: float, predicted spectrogram.
+            target (Variable): shape(B, T, C), dtype: float, target spectrogram.
+            mask (Variable): shape(B, T), mask.
+            priority_bin (int, optional): frequency bands for linear spectrogram loss to be prioritized. Defaults to None.
+
+        Returns:
+            Variable: shape(1,), dtype: float, l1 loss(with mask and possibly priority bin applied.)
+        """
         abs_diff = F.abs(prediction - target)
 
         # basic mask-weighted l1 loss
@@ -103,6 +146,16 @@ class TTSLoss(object):
         return loss
 
     def binary_divergence(self, prediction, target, mask):
+        """Binary cross entropy loss for spectrogram. All the values in the spectrogram are treated as logits in a logistic regression.
+
+        Args:
+            prediction (Variable): shape(B, T, C), dtype: float, predicted spectrogram.
+            target (Variable): shape(B, T, C), dtype: float, target spectrogram.
+            mask (Variable): shape(B, T), mask.
+
+        Returns:
+            Variable: shape(1,), dtype: float, binary cross entropy loss.
+        """
         flattened_prediction = F.reshape(prediction, [-1, 1])
         flattened_target = F.reshape(target, [-1, 1])
         flattened_loss = F.log_loss(
@@ -119,6 +172,15 @@ class TTSLoss(object):
 
     @staticmethod
     def done_loss(done_hat, done):
+        """Compute done loss
+
+        Args:
+            done_hat (Variable): shape(B, T), dtype: float, predicted done probability(the probability that the final frame has been generated.)
+            done (Variable): shape(B, T), dtype: float, ground truth done probability(the probability that the final frame has been generated.)
+
+        Returns:
+            Variable: shape(1, ), dtype: float, done loss.
+        """
         flat_done_hat = F.reshape(done_hat, [-1, 1])
         flat_done = F.reshape(done, [-1, 1])
         loss = F.log_loss(flat_done_hat, flat_done, epsilon=1e-8)
@@ -128,21 +190,15 @@ class TTSLoss(object):
     def attention_loss(self, predicted_attention, input_lengths,
                        target_lengths):
         """
-        Given valid encoder_lengths and decoder_lengths, compute a diagonal 
-        guide, and compute loss from the predicted attention and the guide.
+        Given valid encoder_lengths and decoder_lengths, compute a diagonal guide, and compute loss from the predicted attention and the guide.
         
         Args:
-            predicted_attention (Variable): Shape(*, B, T_dec, T_enc), the 
-                alignment tensor, where B means batch size, T_dec means number
-                of time steps of the decoder, T_enc means the number of time
-                steps of the encoder, * means other possible dimensions.
-            input_lengths (numpy.ndarray): Shape(B,), dtype:int64, valid lengths
-                (time steps) of encoder outputs.
-            target_lengths (numpy.ndarray): Shape(batch_size,), dtype:int64, 
-                valid lengths (time steps) of decoder outputs.
+            predicted_attention (Variable): shape(*, B, T_dec, T_enc), dtype: float, the alignment tensor, where B means batch size, T_dec means number of time steps of the decoder, T_enc means the number of time steps of the encoder, * means other possible dimensions.
+            input_lengths (numpy.ndarray): shape(B,), dtype:int64, valid lengths (time steps) of encoder outputs.
+            target_lengths (numpy.ndarray): shape(batch_size,), dtype:int64, valid lengths (time steps) of decoder outputs.
         
         Returns:
-            loss (Variable): Shape(1, ) attention loss.
+            loss (Variable): shape(1, ), dtype: float, attention loss.
         """
         n_attention, batch_size, max_target_len, max_input_len = (
             predicted_attention.shape)
@@ -167,6 +223,26 @@ class TTSLoss(object):
                  compute_mel_loss=True,
                  compute_done_loss=True,
                  compute_attn_loss=True):
+        """Total loss
+
+        Args:
+            mel_hyp (Variable): shape(B, T, C_mel), dtype, float, predicted mel spectrogram.
+            lin_hyp (Variable): shape(B, T, C_lin), dtype, float, predicted linear spectrogram.
+            done_hyp (Variable): shape(B, T), dtype, float, predicted done probability.
+            attn_hyp (Variable): shape(N, B, T_dec, T_enc), dtype: float, predicted attention.
+            mel_ref (Variable): shape(B, T, C_mel), dtype, float, ground truth mel spectrogram.
+            lin_ref (Variable): shape(B, T, C_lin), dtype, float, ground truth linear spectrogram.
+            done_ref (Variable): shape(B, T), dtype, float, ground truth done flag.
+            input_lengths (Variable): shape(B, ), dtype: int, encoder valid lengths.
+            n_frames (Variable): shape(B, ), dtype: int, decoder valid lengths.
+            compute_lin_loss (bool, optional): whether to compute linear loss. Defaults to True.
+            compute_mel_loss (bool, optional): whether to compute mel loss. Defaults to True.
+            compute_done_loss (bool, optional): whether to compute done loss. Defaults to True.
+            compute_attn_loss (bool, optional): whether to compute atention loss. Defaults to True.
+
+        Returns:
+            Dict(str, Variable): details of loss.
+        """
         total_loss = 0.
 
         # n_frames # mel_lengths # decoder_lengths

parakeet/models/deepvoice3/model.py

@@ -22,6 +22,15 @@ import paddle.fluid.dygraph as dg
 class DeepVoice3(dg.Layer):
     def __init__(self, encoder, decoder, converter, speaker_embedding,
                  use_decoder_states):
+        """Deep Voice 3 TTS model.
+
+        Args:
+            encoder (Layer): the encoder.
+            decoder (Layer): the decoder.
+            converter (Layer): the converter.
+            speaker_embedding (Layer): the speaker embedding (for multispeaker cases).
+            use_decoder_states (bool): use decoder states instead of predicted mel spectrogram as the input of the converter.
+        """
         super(DeepVoice3, self).__init__()
         if speaker_embedding is None:
             self.n_speakers = 1
@@ -34,6 +43,24 @@ class DeepVoice3(dg.Layer):
 
     def forward(self, text_sequences, text_positions, valid_lengths,
                 speaker_indices, mel_inputs, frame_positions):
+        """Compute predicted value in a teacher forcing training manner.
+
+        Args:
+            text_sequences (Variable): shape(B, T_enc), dtype: int64, text indices.
+            text_positions (Variable): shape(B, T_enc), dtype: int64, positions of text indices.
+            valid_lengths (Variable): shape(B, ), dtype: int64, valid lengths of utterances.
+            speaker_indices (Variable): shape(B, ), dtype: int64, speaker indices for utterances.
+            mel_inputs (Variable): shape(B, T_mel, C_mel), dytpe: int64, ground truth mel spectrogram.
+            frame_positions (Variable): shape(B, T_dec), dtype: int64, positions of decoder steps.
+
+        Returns:
+            (mel_outputs, linear_outputs, alignments, done)
+            mel_outputs (Variable): shape(B, T_mel, C_mel), dtype: float, predicted mel spectrogram.
+            mel_outputs (Variable): shape(B, T_mel, C_mel), dtype: float, predicted mel spectrogram.
+            alignments (Variable): shape(N, B, T_dec, T_enc), dtype: float, predicted attention.
+            done (Variable): shape(B, T_dec), dtype: float, predicted done probability.
+            (T_mel: time steps of mel spectrogram, T_lin: time steps of linear spectrogra, T_dec, time steps of decoder, T_enc: time steps of encoder.)
+        """
         if hasattr(self, "speaker_embedding"):
             speaker_embed = self.speaker_embedding(speaker_indices)
         else:
@@ -49,6 +76,21 @@ class DeepVoice3(dg.Layer):
         return mel_outputs, linear_outputs, alignments, done
 
     def transduce(self, text_sequences, text_positions, speaker_indices=None):
+        """Generate output without teacher forcing. Only batch_size = 1 is supported.
+
+        Args:
+            text_sequences (Variable): shape(B, T_enc), dtype: int64, text indices.
+            text_positions (Variable): shape(B, T_enc), dtype: int64, positions of text indices.
+            speaker_indices (Variable): shape(B, ), dtype: int64, speaker indices for utterances.
+
+        Returns:
+            (mel_outputs, linear_outputs, alignments, done)
+            mel_outputs (Variable): shape(B, T_mel, C_mel), dtype: float, predicted mel spectrogram.
+            mel_outputs (Variable): shape(B, T_mel, C_mel), dtype: float, predicted mel spectrogram.
+            alignments (Variable): shape(B, T_dec, T_enc), dtype: float, predicted average attention of all attention layers.
+            done (Variable): shape(B, T_dec), dtype: float, predicted done probability.
+            (T_mel: time steps of mel spectrogram, T_lin: time steps of linear spectrogra, T_dec, time steps of decoder, T_enc: time steps of encoder.)
+        """
         if hasattr(self, "speaker_embedding"):
             speaker_embed = self.speaker_embedding(speaker_indices)
         else:

parakeet/models/deepvoice3/position_embedding.py

@@ -19,14 +19,14 @@ import paddle.fluid.dygraph as dg
 
 
 def compute_position_embedding(radians, speaker_position_rate):
-    """compute sin/cos separately and scatter them to a zero.
+    """Compute sin/cos interleaved matrix from the radians.
     
-    Arguments:
-        radians {Variable} -- shape(n_vocab, embed_dim), the radians matrix.
-        speaker_position_rate {Variable} -- shape(batch_size, ), speaker positioning rate.
+    Arg:
+        radians (Variable): shape(n_vocab, embed_dim), dtype: float, the radians matrix.
+        speaker_position_rate (Variable): shape(B, ), speaker positioning rate.
     
     Returns:
-        Variable -- shape(batch_size, n_vocab, embed_dim), the sin, cos matrix.
+        Variable: shape(B, n_vocab, embed_dim), the sin, cos interleaved matrix.
     """
     _, embed_dim = radians.shape
     batch_size = speaker_position_rate.shape[0]
@@ -48,10 +48,20 @@ def position_encoding_init(n_position,
                            d_pos_vec,
                            position_rate=1.0,
                            padding_idx=None):
-    """init the position encoding table"""
+    """Init the position encoding.
+
+    Args:
+        n_position (int): max position, vocab size for position embedding.
+        d_pos_vec (int): position embedding size.
+        position_rate (float, optional): position rate (this should only be used when all the utterances are from one speaker.). Defaults to 1.0.
+        padding_idx (int, optional): padding index for the position embedding(it is set as 0 internally if not provided.). Defaults to None.
+
+    Returns:
+        [type]: [description]
+    """
+    # init the position encoding table
     # keep idx 0 for padding token position encoding zero vector
     # CAUTION: it is radians here, sin and cos are not applied
-    # CAUTION: difference here
     indices_range = np.expand_dims(np.arange(n_position), -1)
     embed_range = 2 * (np.arange(d_pos_vec) // 2)
     radians = position_rate \
@@ -63,31 +73,32 @@ def position_encoding_init(n_position,
 
 
 class PositionEmbedding(dg.Layer):
-    def __init__(self,
-                 n_position,
-                 d_pos_vec,
-                 position_rate=1.0,
-                 param_attr=None,
-                 max_norm=None,
-                 padding_idx=None):
+    def __init__(self, n_position, d_pos_vec, position_rate=1.0):
+        """Position Embedding for Deep Voice 3.
+
+        Args:
+            n_position (int): max position, vocab size for position embedding.
+            d_pos_vec (int): position embedding size.
+            position_rate (float, optional): position rate (this should only be used when all the utterances are from one speaker.). Defaults to 1.0.
+        """
         super(PositionEmbedding, self).__init__()
         self.weight = self.create_parameter((n_position, d_pos_vec))
         self.weight.set_value(
-            position_encoding_init(n_position, d_pos_vec, position_rate,
-                                   padding_idx).astype("float32"))
+            position_encoding_init(n_position, d_pos_vec, position_rate)
+            .astype("float32"))
 
     def forward(self, indices, speaker_position_rate=None):
         """
         Args:
-            indices (Variable): Shape (B, T), dtype: int64, position
+            indices (Variable): shape (B, T), dtype: int64, position
                 indices, where B means the batch size, T means the time steps.
             speaker_position_rate (Variable | float, optional), position
                 rate. It can be a float point number or a Variable with 
                 shape (1,), then this speaker_position_rate is used for every 
-                example. It can also be a Variable with shape (B, 1), which 
-                contains a speaker position rate for each speaker.
+                example. It can also be a Variable with shape (B, ), which 
+                contains a speaker position rate for each utterance.
         Returns:
-            out (Variable): Shape(B, T, C_pos), position embedding, where C_pos 
+            out (Variable): shape(B, T, C_pos), dtype: float, position embedding, where C_pos 
                 means position embedding size.
         """
         batch_size, time_steps = indices.shape

parakeet/models/wavenet/net.py

@@ -27,17 +27,16 @@ from parakeet.models.wavenet.wavenet import WaveNet
 
 
 def crop(x, audio_start, audio_length):
-    """Crop mel spectrogram.
-    
+    """Crop the upsampled condition to match audio_length. The upsampled condition has the same time steps as the whole audio does. But since audios are sliced to 0.5 seconds randomly while conditions are not, upsampled conditions should also be sliced to extaclt match the time steps of the audio slice.
+
     Args:
-        x (Variable): shape(batch_size, channels, time_steps), the condition, upsampled mel spectrogram.
-        audio_start (int): starting point.
-        audio_length (int): length.
-    
+        x (Variable): shape(B, C, T), dtype: float, the upsample condition.
+        audio_start (Variable): shape(B, ), dtype: int64, the index the starting point.
+        audio_length (int): the length of the audio (number of samples it contaions).
+
     Returns:
-        out: cropped condition.
+        Variable: shape(B, C, audio_length), cropped condition.
     """
-
     # crop audio
     slices = []  # for each example
     starts = audio_start.numpy()
@@ -51,12 +50,15 @@ def crop(x, audio_start, audio_length):
 
 
 class UpsampleNet(dg.Layer):
-    """A upsampling net (bridge net) in clarinet to upsample spectrograms from frame level to sample level.
-    It consists of several(2) layers of transposed_conv2d. in time and frequency.
-    The time dim is dilated hop_length times. The frequency bands retains.
-    """
-
     def __init__(self, upscale_factors=[16, 16]):
+        """UpsamplingNet.
+        It consists of several layers of Conv2DTranspose. Each Conv2DTranspose layer upsamples the time dimension by its `stride` times. And each Conv2DTranspose's filter_size at frequency dimension is 3.
+
+        Args:
+            upscale_factors (list[int], optional): time upsampling factors for each Conv2DTranspose Layer. The `UpsampleNet` contains len(upscale_factor) Conv2DTranspose Layers. Each upscale_factor is used as the `stride` for the corresponding Conv2DTranspose. Defaults to [16, 16].
+        Note:
+            np.prod(upscale_factors) should equals the `hop_length` of the stft transformation used to extract spectrogram features from audios. For example, 16 * 16 = 256, then the spectram extracted using a stft transformation whose `hop_length` is 256. See `librosa.stft` for more details.
+        """
         super(UpsampleNet, self).__init__()
         self.upscale_factors = list(upscale_factors)
         self.upsample_convs = dg.LayerList()
@@ -74,13 +76,13 @@ class UpsampleNet(dg.Layer):
         return np.prod(self.upscale_factors)
 
     def forward(self, x):
-        """upsample local condition to match time steps of input signals. i.e. upsample mel spectrogram to match time steps for waveform, for each layer of a wavenet.
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, frequency, time_steps), local condition
-        
+        """Compute the upsampled condition.
+
+        Args:
+            x (Variable): shape(B, F, T), dtype: float, the condition (mel spectrogram here.) (F means the frequency bands). In the internal Conv2DTransposes, the frequency dimension is treated as `height` dimension instead of `in_channels`.
+
         Returns:
-            Variable -- shape(batch_size, frequency, time_steps * np.prod(upscale_factors)), upsampled condition for each layer.
+            Variable: shape(B, F, T * upscale_factor), dtype: float, the upsampled condition.
         """
         x = F.unsqueeze(x, axes=[1])
         for sublayer in self.upsample_convs:
@@ -91,27 +93,31 @@ class UpsampleNet(dg.Layer):
 
 # AutoRegressive Model
 class ConditionalWavenet(dg.Layer):
-    def __init__(self, encoder: UpsampleNet, decoder: WaveNet):
+    def __init__(self, encoder, decoder):
+        """Conditional Wavenet, which contains an UpsampleNet as the encoder and a WaveNet as the decoder. It is an autoregressive model.
+
+        Args:
+            encoder (UpsampleNet): the UpsampleNet as the encoder.
+            decoder (WaveNet): the WaveNet as the decoder.
+        """
         super(ConditionalWavenet, self).__init__()
         self.encoder = encoder
         self.decoder = decoder
 
     def forward(self, audio, mel, audio_start):
-        """forward
-        
-        Arguments:
-            audio {Variable} -- shape(batch_size, time_steps), waveform of 0.5 seconds
-            mel {Variable} -- shape(batch_size, frequency_bands, frames), mel spectrogram of the whole sentence
-            audio_start {Variable} -- shape(batch_size, ), audio start positions
-        
+        """Compute the output distribution given the mel spectrogram and the input(for teacher force training).
+
+        Args:
+            audio (Variable): shape(B, T_audio), dtype: float, ground truth waveform, used for teacher force training.
+            mel ([Variable): shape(B, F, T_mel), dtype: float, mel spectrogram. Note that it is the spectrogram for the whole utterance.
+            audio_start (Variable): shape(B, ), dtype: int, audio slices' start positions for each utterance.
+
         Returns:
-            Variable -- shape(batch_size, time_steps - 1, output_dim), output distribution parameters
+            Variable: shape(B, T_audio - 1, C_putput), parameters for the output distribution.(C_output is the `output_dim` of the decoder.)
         """
-
         audio_length = audio.shape[1]  # audio clip's length
         condition = self.encoder(mel)
-        condition_slice = crop(condition, audio_start,
-                               audio_length)  # crop audio
+        condition_slice = crop(condition, audio_start, audio_length)
 
         # shifting 1 step
         audio = audio[:, :-1]
@@ -121,43 +127,41 @@ class ConditionalWavenet(dg.Layer):
         return y
 
     def loss(self, y, t):
-        """compute loss
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution parameters
-            t {Variable} -- shape(batch_size, time_steps), target waveform
-        
+        """compute loss with respect to the output distribution and the targer audio.
+
+        Args:
+            y (Variable): shape(B, T - 1, C_output), dtype: float, parameters of the output distribution.
+            t (Variable): shape(B, T), dtype: float, target waveform.
+
         Returns:
-            Variable -- shape(1, ), reduced loss 
+            Variable: shape(1, ), dtype: float, the loss.
         """
         t = t[:, 1:]
         loss = self.decoder.loss(y, t)
         return loss
 
     def sample(self, y):
-        """sample from output distribution
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps, output_dim), output distribution parameters
-        
+        """Sample from the output distribution.
+
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, parameters of the output distribution.
+
         Returns:
-            Variable -- shape(batch_size, time_steps) samples
+            Variable: shape(B, T), dtype: float, sampled waveform from the output distribution.
         """
-
         samples = self.decoder.sample(y)
         return samples
 
     @dg.no_grad
     def synthesis(self, mel):
-        """synthesize waveform from mel spectrogram
-        
-        Arguments:
-            mel {Variable} -- shape(batch_size, frequency_bands, frames), mel-spectrogram
-        
+        """Synthesize waveform from mel spectrogram.
+
+        Args:
+            mel (Variable): shape(B, F, T), condition(mel spectrogram here).
+
         Returns:
-            Variable -- shape(batch_size, time_steps), synthesized waveform.
+            Variable: shape(B, T * upsacle_factor), synthesized waveform.(`upscale_factor` is the `upscale_factor` of the encoder `UpsampleNet`)
         """
-
         condition = self.encoder(mel)
         batch_size, _, time_steps = condition.shape
         samples = []

parakeet/models/wavenet/wavenet.py

@@ -27,11 +27,29 @@ from parakeet.modules.weight_norm import Linear, Conv1D, Conv1DCell, Conv2DTrans
 
 # for wavenet with softmax loss
 def quantize(values, n_bands):
+    """Linearlly quantize a float Tensor in [-1, 1) to an interger Tensor in [0, n_bands).
+
+    Args:
+        values (Variable): dtype: flaot32 or float64. the floating point value.
+        n_bands (int): the number of bands. The output integer Tensor's value is in the range [0, n_bans).
+
+    Returns:
+        Variable: the quantized tensor, dtype: int64.
+    """
     quantized = F.cast((values + 1.0) / 2.0 * n_bands, "int64")
     return quantized
 
 
 def dequantize(quantized, n_bands):
+    """Linearlly dequantize an integer Tensor into a float Tensor in the range [-1, 1).
+
+    Args:
+        quantized (Variable): dtype: int64. The quantized value in the range [0, n_bands).
+        n_bands (int): number of bands. The input integer Tensor's value is in the range [0, n_bans).
+
+    Returns:
+        Variable: the dequantized tensor, dtype: float32.
+    """
     value = (F.cast(quantized, "float32") + 0.5) * (2.0 / n_bands) - 1.0
     return value
 
@@ -39,6 +57,14 @@ def dequantize(quantized, n_bands):
 class ResidualBlock(dg.Layer):
     def __init__(self, residual_channels, condition_dim, filter_size,
                  dilation):
+        """A Residual block in wavenet. It does not have parametric residual or skip connection. It consists of a Conv1DCell and an Conv1D(filter_size = 1) to integrate the condition.
+
+        Args:
+            residual_channels (int): the channels of the input, residual and skip.
+            condition_dim (int): the channels of the condition.
+            filter_size (int): filter size of the internal convolution cell.
+            dilation (int): dilation of the internal convolution cell.
+        """
         super(ResidualBlock, self).__init__()
         dilated_channels = 2 * residual_channels
         # following clarinet's implementation, we do not have parametric residual
@@ -64,17 +90,16 @@ class ResidualBlock(dg.Layer):
         self.condition_dim = condition_dim
 
     def forward(self, x, condition=None):
-        """Conv1D gated tanh Block
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, residual_channels, time_steps), the input.
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim, time_steps), upsampled local condition, it has the shape time steps as the input x. (default: {None})
-        
+        """Conv1D gated-tanh Block.
+
+        Args:
+            x (Variable): shape(B, C_res, T), the input. (B stands for batch_size, C_res stands for residual channels, T stands for time steps.) dtype: float.
+            condition (Variable, optional): shape(B, C_cond, T), the condition, it has been upsampled in time steps, so it has the same time steps as the input does.(C_cond stands for the condition's channels). Defaults to None.
+
         Returns:
-            Variable -- shape(batch_size, residual_channels, time_steps), the output which is used as the input of the next layer.
-            Variable -- shape(batch_size, residual_channels, time_steps), the output which is stacked alongside with other layers' as the output of wavenet.
+            (residual, skip_connection)
+            residual (Variable): shape(B, C_res, T), the residual, which is used as the input to the next layer of ResidualBlock.
+            skip_connection (Variable): shape(B, C_res, T), the skip connection. This output is accumulated with that of other ResidualBlocks. 
         """
         time_steps = x.shape[-1]
         h = x
@@ -98,20 +123,21 @@ class ResidualBlock(dg.Layer):
         return residual, skip_connection
 
     def start_sequence(self):
+        """Prepare the ResidualBlock to generate a new sequence. This method should be called before starting calling `add_input` multiple times.
+        """
         self.conv.start_sequence()
 
     def add_input(self, x, condition=None):
-        """add a step input.
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, in_channels, time_steps=1), step input
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim, time_steps=1) (default: {None})
-        
+        """Add a step input. This method works similarily with `forward` but in a `step-in-step-out` fashion.
+
+        Args:
+            x (Variable): shape(B, C_res, T=1), input for a step, dtype: float.
+            condition (Variable, optional): shape(B, C_cond, T=1). condition for a step, dtype: float. Defaults to None.
+
         Returns:
-            Variable -- shape(batch_size, in_channels, time_steps=1), residual connection, which is the input for the next layer
-            Variable -- shape(batch_size, in_channels, time_steps=1), skip connection
+            (residual, skip_connection)
+            residual (Variable): shape(B, C_res, T=1), the residual for a step, which is used as the input to the next layer of ResidualBlock.
+            skip_connection (Variable): shape(B, C_res, T=1), the skip connection for a step. This output is accumulated with that of other ResidualBlocks. 
         """
         h = x
 
@@ -135,6 +161,15 @@ class ResidualBlock(dg.Layer):
 class ResidualNet(dg.Layer):
     def __init__(self, n_loop, n_layer, residual_channels, condition_dim,
                  filter_size):
+        """The residual network in wavenet. It consists of `n_layer` stacks, each of which consists of `n_loop` ResidualBlocks.
+
+        Args:
+            n_loop (int): number of ResidualBlocks in a stack.
+            n_layer (int): number of stacks in the `ResidualNet`.
+            residual_channels (int): channels of each `ResidualBlock`'s input.
+            condition_dim (int): channels of the condition.
+            filter_size (int): filter size of the internal Conv1DCell of each `ResidualBlock`.
+        """
         super(ResidualNet, self).__init__()
         # double the dilation at each layer in a loop(n_loop layers)
         dilations = [2**i for i in range(n_loop)] * n_layer
@@ -145,19 +180,14 @@ class ResidualNet(dg.Layer):
         ])
 
     def forward(self, x, condition=None):
-        """n_layer layers of n_loop Residual Blocks.
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, residual_channels, time_steps), input of the residual net.
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim, time_steps), upsampled conditions, which has the same time steps as the input. (default: {None})
-        
-        Returns:
-            Variable -- shape(batch_size, skip_channels, time_steps), output of the residual net.
         """
+        Args:
+            x (Variable): shape(B, C_res, T), dtype: float, the input. (B stands for batch_size, C_res stands for residual channels, T stands for time steps.)
+            condition (Variable, optional): shape(B, C_cond, T), dtype: float, the condition, it has been upsampled in time steps, so it has the same time steps as the input does.(C_cond stands for the condition's channels) Defaults to None.
 
-        #before_resnet = time.time()
+        Returns:
+            skip_connection (Variable): shape(B, C_res, T), dtype: float, the output.
+        """
         for i, func in enumerate(self.residual_blocks):
             x, skip = func(x, condition)
             if i == 0:
@@ -165,24 +195,23 @@ class ResidualNet(dg.Layer):
             else:
                 skip_connections = F.scale(skip_connections + skip,
                                            np.sqrt(0.5))
-        #print("resnet: ", time.time() - before_resnet)
         return skip_connections
 
     def start_sequence(self):
+        """Prepare the ResidualNet to generate a new sequence. This method should be called before starting calling `add_input` multiple times.
+        """
         for block in self.residual_blocks:
             block.start_sequence()
 
     def add_input(self, x, condition=None):
-        """add step input and return step output.
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, residual_channels, time_steps=1), step input.
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim, time_steps=1), step condition (default: {None})
-        
+        """Add a step input. This method works similarily with `forward` but in a `step-in-step-out` fashion.
+
+        Args:
+            x (Variable): shape(B, C_res, T=1), dtype: float, input for a step.
+            condition (Variable, optional): shape(B, C_cond, T=1), dtype: float, condition for a step. Defaults to None.
+
         Returns:
-            Variable -- shape(batch_size, skip_channels, time_steps=1), step output, parameters of the output distribution.
+            skip_connection (Variable): shape(B, C_res, T=1), dtype: float, the output for a step.
         """
 
         for i, func in enumerate(self.residual_blocks):
@@ -198,6 +227,18 @@ class ResidualNet(dg.Layer):
 class WaveNet(dg.Layer):
     def __init__(self, n_loop, n_layer, residual_channels, output_dim,
                  condition_dim, filter_size, loss_type, log_scale_min):
+        """Wavenet that transform upsampled mel spectrogram into waveform.
+
+        Args:
+            n_loop (int): n_loop for the internal ResidualNet.
+            n_layer (int): n_loop for the internal ResidualNet.
+            residual_channels (int): the channel of the input.
+            output_dim (int): the channel of the output distribution. 
+            condition_dim (int): the channel of the condition.
+            filter_size (int): the filter size of the internal ResidualNet.
+            loss_type (str): loss type of the wavenet. Possible values are 'softmax' and 'mog'. If `loss_type` is 'softmax', the output is the logits of the catrgotical(multinomial) distribution, `output_dim` means the number of classes of the categorical distribution. If `loss_type` is mog(mixture of gaussians), the output is the parameters of a mixture of gaussians, which consists of weight(in the form of logit) of each gaussian distribution and its mean and log standard deviaton. So when `loss_type` is 'mog', `output_dim` should be perfectly divided by 3.
+            log_scale_min (int): the minimum value of log standard deviation of the output gaussian distributions. Note that this value is only used for computing loss if `loss_type` is 'mog', values less than `log_scale_min` is clipped when computing loss.
+        """
         super(WaveNet, self).__init__()
         if loss_type not in ["softmax", "mog"]:
             raise ValueError("loss_type {} is not supported".format(loss_type))
@@ -225,19 +266,16 @@ class WaveNet(dg.Layer):
         self.log_scale_min = log_scale_min
 
     def forward(self, x, condition=None):
-        """(Possibly) Conditonal Wavenet.
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, time_steps), the input signal of wavenet. The waveform in 0.5 seconds.
-        
-        Keyword Arguments:
-            conditions {Variable} -- shape(batch_size, condition_dim, 1, time_steps), the upsampled local condition. (default: {None})
-        
+        """compute the output distribution (represented by its parameters).
+
+        Args:
+            x (Variable): shape(B, T), dtype: float, the input waveform.
+            condition (Variable, optional): shape(B, C_cond, T), dtype: float, the upsampled condition. Defaults to None.
+
         Returns:
-            Variable -- shape(batch_size, time_steps, output_dim), output distributions at each time_steps. 
+            Variable: shape(B, T, C_output), dtype: float, the parameter of the output distributions.
         """
 
-        # CAUTION: rank-4 condition here
         # Causal Conv
         if self.loss_type == "softmax":
             x = F.clip(x, min=-1., max=0.99999)
@@ -258,21 +296,20 @@ class WaveNet(dg.Layer):
         return y
 
     def start_sequence(self):
+        """Prepare the WaveNet to generate a new sequence. This method should be called before starting calling `add_input` multiple times.
+        """
         self.resnet.start_sequence()
 
     def add_input(self, x, condition=None):
-        """add step input
-        
-        Arguments:
-            x {Variable} -- shape(batch_size, time_steps=1), step input.
-        
-        Keyword Arguments:
-            condition {Variable} -- shape(batch_size, condition_dim , 1, time_steps=1) (default: {None})
-        
+        """compute the output distribution (represented by its parameters) for a step. It works similarily with the `forward` method but in a `step-in-step-out` fashion.
+
+        Args:
+            x (Variable): shape(B, T=1), dtype: float, a step of the input waveform.
+            condition (Variable, optional): shape(B, C_cond, T=1), dtype: float, a step of the upsampled condition. Defaults to None.
+
         Returns:
-            Variable -- ouput parameter for the distribution.
+            Variable: shape(B, T=1, C_output), dtype: float, the parameter of the output distributions.
         """
-
         # Causal Conv
         if self.loss_type == "softmax":
             x = quantize(x, self.output_dim)
@@ -292,16 +329,15 @@ class WaveNet(dg.Layer):
         return y
 
     def compute_softmax_loss(self, y, t):
-        """compute loss, it is basically a language_model-like loss.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution of multinomial distribution.
-            t {Variable} -- shape(batch_size, time_steps - 1), target waveform.
-        
+        """compute the loss where output distribution is a categorial distribution.
+
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, the logits of the output distribution.
+            t (Variable): shape(B, T), dtype: float, the target audio. Note that the target's corresponding time index is one step ahead of the output distribution. And output distribution whose input contains padding is neglected in loss computation.
+
         Returns:
-            Variable -- shape(1,), loss
+            Variable: shape(1, ), dtype: float, the loss.
         """
-
         # context size is not taken into account
         y = y[:, self.context_size:, :]
         t = t[:, self.context_size:]
@@ -314,15 +350,14 @@ class WaveNet(dg.Layer):
         return reduced_loss
 
     def sample_from_softmax(self, y):
-        """sample from output distribution.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution.
-        
+        """Sample from the output distribution where the output distribution is a categorical distriobution.
+
+        Args:
+            y (Variable): shape(B, T, C_output), the logits of the output distribution
+
         Returns:
-            Variable -- shape(batch_size, time_steps - 1), samples.
+            Variable: shape(B, T), waveform sampled from the output distribution.
         """
-
         # dequantize
         batch_size, time_steps, output_dim, = y.shape
         y = F.reshape(y, (batch_size * time_steps, output_dim))
@@ -333,17 +368,15 @@ class WaveNet(dg.Layer):
         return samples
 
     def compute_mog_loss(self, y, t):
-        """compute the loss with an mog output distribution.
-        WARNING: this is not a legal probability, but a density. so it might be greater than 1.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps, output_dim), output distribution's parameter. To represent a mixture of Gaussians. The output for each example at each time_step consists of 3 parts. The mean, the stddev, and a weight for that gaussian.
-            t {Variable} -- shape(batch_size, time_steps), target waveform.
+        """compute the loss where output distribution is a mixture of Gaussians.
+
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, the parameterd of the output distribution. It is the concatenation of 3 parts, the logits of every distribution, the mean of each distribution and the log standard deviation of each distribution. Each part's shape is (B, T, n_mixture), where `n_mixture` means the number of Gaussians in the mixture.
+            t (Variable): shape(B, T), dtype: float, the target audio. Note that the target's corresponding time index is one step ahead of the output distribution. And output distribution whose input contains padding is neglected in loss computation.
 
         Returns:
-            Variable -- loss, note that it is computed with the pdf of the MoG distribution. 
+            Variable: shape(1, ), dtype: float, the loss.
         """
-
         n_mixture = self.output_dim // 3
 
         # context size is not taken in to account
@@ -373,15 +406,13 @@ class WaveNet(dg.Layer):
         return loss
 
     def sample_from_mog(self, y):
-        """sample from output distribution.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution.
-        
+        """Sample from the output distribution where the output distribution is a mixture of Gaussians.
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, the parameterd of the output distribution. It is the concatenation of 3 parts, the logits of every distribution, the mean of each distribution and the log standard deviation of each distribution. Each part's shape is (B, T, n_mixture), where `n_mixture` means the number of Gaussians in the mixture.
+
         Returns:
-            Variable -- shape(batch_size, time_steps - 1), samples.
+            Variable: shape(B, T), waveform sampled from the output distribution.
         """
-
         batch_size, time_steps, output_dim = y.shape
         n_mixture = output_dim // 3
 
@@ -405,31 +436,28 @@ class WaveNet(dg.Layer):
         return samples
 
     def sample(self, y):
-        """sample from output distribution.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution.
-        
+        """Sample from the output distribution.
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, the parameterd of the output distribution.
+
         Returns:
-            Variable -- shape(batch_size, time_steps - 1), samples.
+            Variable: shape(B, T), waveform sampled from the output distribution.
         """
-
         if self.loss_type == "softmax":
             return self.sample_from_softmax(y)
         else:
             return self.sample_from_mog(y)
 
     def loss(self, y, t):
-        """compute loss.
-        
-        Arguments:
-            y {Variable} -- shape(batch_size, time_steps - 1, output_dim), output distribution of multinomial distribution.
-            t {Variable} -- shape(batch_size, time_steps - 1), target waveform.
-        
+        """compute the loss where output distribution is a mixture of Gaussians.
+
+        Args:
+            y (Variable): shape(B, T, C_output), dtype: float, the parameterd of the output distribution.
+            t (Variable): shape(B, T), dtype: float, the target audio. Note that the target's corresponding time index is one step ahead of the output distribution. And output distribution whose input contains padding is neglected in loss computation.
+
         Returns:
-            Variable -- shape(1,), loss
+            Variable: shape(1, ), dtype: float, the loss.
         """
-
         if self.loss_type == "softmax":
             return self.compute_softmax_loss(y, t)
         else: