This class can wrap an encoder model, such as ``BertModel`` and a decoder modeling with a language modeling head, such as ``BertForMaskedLM`` into a encoder-decoder model.
This class can wrap an encoder model, such as ``BertModel`` and a decoder modeling with a language modeling head, such as ``BertForMaskedLM`` into a encoder-decoder model.
...
@@ -10,7 +10,7 @@ An application of this architecture could be *summarization* using two pretraine
...
@@ -10,7 +10,7 @@ An application of this architecture could be *summarization* using two pretraine
file a `Github Issue <https://github.com/huggingface/transformers/issues/new?assignees=&labels=&template=bug-report.md&title>`_
file a `Github Issue <https://github.com/huggingface/transformers/issues/new?assignees=&labels=&template=bug-report.md&title>`_
Overview
Overview
~~~~~
~~~~~~~~~~
The Reformer model was presented in `Reformer: The Efficient Transformer <https://arxiv.org/abs/2001.04451.pdf>`_ by Nikita Kitaev, Łukasz Kaiser, Anselm Levskaya.
The Reformer model was presented in `Reformer: The Efficient Transformer <https://arxiv.org/abs/2001.04451.pdf>`_ by Nikita Kitaev, Łukasz Kaiser, Anselm Levskaya.
Here the abstract:
Here the abstract:
...
@@ -13,7 +13,7 @@ Here the abstract:
...
@@ -13,7 +13,7 @@ Here the abstract:
The Authors' code can be found `here <https://github.com/google/trax/tree/master/trax/models/reformer>`_ .
The Authors' code can be found `here <https://github.com/google/trax/tree/master/trax/models/reformer>`_ .
Axial Positional Encodings
Axial Positional Encodings
~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Axial Positional Encodings were first implemented in Google's `trax library <https://github.com/google/trax/blob/4d99ad4965bab1deba227539758d59f0df0fef48/trax/layers/research/position_encodings.py#L29>`_ and developed by the authors of this model's paper. In models that are treating very long input sequences, the conventional position id encodings store an embedings vector of size :math:`d` being the ``config.hidden_size`` for every position :math:`i, \ldots, n_s`, with :math:`n_s` being ``config.max_embedding_size``. *E.g.*, having a sequence length of :math:`n_s = 2^{19} \approx 0.5M` and a ``config.hidden_size`` of :math:`d = 2^{10} \approx 1000` would result in a position encoding matrix:
Axial Positional Encodings were first implemented in Google's `trax library <https://github.com/google/trax/blob/4d99ad4965bab1deba227539758d59f0df0fef48/trax/layers/research/position_encodings.py#L29>`_ and developed by the authors of this model's paper. In models that are treating very long input sequences, the conventional position id encodings store an embedings vector of size :math:`d` being the ``config.hidden_size`` for every position :math:`i, \ldots, n_s`, with :math:`n_s` being ``config.max_embedding_size``. *E.g.*, having a sequence length of :math:`n_s = 2^{19} \approx 0.5M` and a ``config.hidden_size`` of :math:`d = 2^{10} \approx 1000` would result in a position encoding matrix:
T5_START_DOCSTRING=r""" The T5 model was proposed in
T5_START_DOCSTRING=r"""
`Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer`_
The T5 model was proposed in `Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer
by Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan Narang, Michael Matena, Yanqi Zhou, Wei Li, Peter J. Liu.
<https://arxiv.org/abs/1910.10683>`__ by Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan Narang,
Michael Matena, Yanqi Zhou, Wei Li, Peter J. Liu.
It's an encoder decoder transformer pre-trained in a text-to-text denoising generative setting.
It's an encoder decoder transformer pre-trained in a text-to-text denoising generative setting.
This model is a PyTorch `torch.nn.Module`_ sub-class. Use it as a regular PyTorch Module and
This model is a PyTorch `torch.nn.Module <https://pytorch.org/docs/stable/nn.html#module>`__ sub-class. Use it as a
refer to the PyTorch documentation for all matter related to general usage and behavior.
regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
.. _`Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer`:
https://arxiv.org/abs/1910.10683
.. _`torch.nn.Module`:
https://pytorch.org/docs/stable/nn.html#module
Parameters:
Parameters:
config (:class:`~transformers.T5Config`): Model configuration class with all the parameters of the model.
config (:class:`~transformers.T5Config`): Model configuration class with all the parameters of the model.
...
@@ -804,7 +799,7 @@ T5_INPUTS_DOCSTRING = r"""
...
@@ -804,7 +799,7 @@ T5_INPUTS_DOCSTRING = r"""
See :func:`transformers.PreTrainedTokenizer.encode` and
See :func:`transformers.PreTrainedTokenizer.encode` and
:func:`transformers.PreTrainedTokenizer.convert_tokens_to_ids` for details.
:func:`transformers.PreTrainedTokenizer.convert_tokens_to_ids` for details.
To know more on how to prepare :obj:`input_ids` for pre-training take a look at
To know more on how to prepare :obj:`input_ids` for pre-training take a look at
`T5 Training <./t5.html#training>`_.
`T5 Training <./t5.html#training>`__.
attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
Mask to avoid performing attention on padding token indices.
Mask to avoid performing attention on padding token indices.
Mask values selected in ``[0, 1]``:
Mask values selected in ``[0, 1]``:
...
@@ -817,7 +812,7 @@ T5_INPUTS_DOCSTRING = r"""
...
@@ -817,7 +812,7 @@ T5_INPUTS_DOCSTRING = r"""
Provide for sequence to sequence training. T5 uses the pad_token_id as the starting token for decoder_input_ids generation.
Provide for sequence to sequence training. T5 uses the pad_token_id as the starting token for decoder_input_ids generation.
If `decoder_past_key_value_states` is used, optionally only the last `decoder_input_ids` have to be input (see `decoder_past_key_value_states`).
If `decoder_past_key_value_states` is used, optionally only the last `decoder_input_ids` have to be input (see `decoder_past_key_value_states`).
To know more on how to prepare :obj:`decoder_input_ids` for pre-training take a look at
To know more on how to prepare :obj:`decoder_input_ids` for pre-training take a look at
`T5 Training <./t5.html#training>`_.
`T5 Training <./t5.html#training>`__.
decoder_attention_mask (:obj:`torch.BoolTensor` of shape :obj:`(batch_size, tgt_seq_len)`, `optional`, defaults to :obj:`None`):
decoder_attention_mask (:obj:`torch.BoolTensor` of shape :obj:`(batch_size, tgt_seq_len)`, `optional`, defaults to :obj:`None`):
Default behavior: generate a tensor that ignores pad tokens in decoder_input_ids. Causal mask will also be used by default.
Default behavior: generate a tensor that ignores pad tokens in decoder_input_ids. Causal mask will also be used by default.
decoder_past_key_value_states (:obj:`tuple(tuple(torch.FloatTensor))` of length :obj:`config.n_layers` with each tuple having 4 tensors of shape :obj:`(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
decoder_past_key_value_states (:obj:`tuple(tuple(torch.FloatTensor))` of length :obj:`config.n_layers` with each tuple having 4 tensors of shape :obj:`(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
...
@@ -902,8 +897,8 @@ class T5Model(T5PreTrainedModel):
...
@@ -902,8 +897,8 @@ class T5Model(T5PreTrainedModel):
output_attentions=None,
output_attentions=None,
):
):
r"""
r"""
Return:
Returns:
:obj:`tuple(torch.FloatTensor)` comprising various elements depending on the configuration (:class:`~transformers.T5Config`) and inputs.
:obj:`tuple(torch.FloatTensor)` comprising various elements depending on the configuration (:class:`~transformers.T5Config`) and inputs:
last_hidden_state (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`):
last_hidden_state (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`):
Sequence of hidden-states at the output of the last layer of the model.
Sequence of hidden-states at the output of the last layer of the model.
If `decoder_past_key_value_states` is used only the last hidden-state of the sequences of shape :obj:`(batch_size, 1, hidden_size)` is output.
If `decoder_past_key_value_states` is used only the last hidden-state of the sequences of shape :obj:`(batch_size, 1, hidden_size)` is output.
...
@@ -1038,7 +1033,7 @@ class T5ForConditionalGeneration(T5PreTrainedModel):
...
@@ -1038,7 +1033,7 @@ class T5ForConditionalGeneration(T5PreTrainedModel):
Used to hide legacy arguments that have been deprecated.
Used to hide legacy arguments that have been deprecated.
Returns:
Returns:
:obj:`tuple(torch.FloatTensor)` comprising various elements depending on the configuration (:class:`~transformers.T5Config`) and inputs.
:obj:`tuple(torch.FloatTensor)` comprising various elements depending on the configuration (:class:`~transformers.T5Config`) and inputs:
loss (:obj:`torch.FloatTensor` of shape :obj:`(1,)`, `optional`, returned when :obj:`labels` is provided):
loss (:obj:`torch.FloatTensor` of shape :obj:`(1,)`, `optional`, returned when :obj:`labels` is provided):
Classification loss (cross entropy).
Classification loss (cross entropy).
prediction_scores (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, config.vocab_size)`)
prediction_scores (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, config.vocab_size)`)
@@ -294,7 +294,6 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin):
...
@@ -294,7 +294,6 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin):
Parameters:
Parameters:
pretrained_model_name_or_path: either:
pretrained_model_name_or_path: either:
- a string with the `shortcut name` of a pre-trained model to load from cache or download, e.g.: ``bert-base-uncased``.
- a string with the `shortcut name` of a pre-trained model to load from cache or download, e.g.: ``bert-base-uncased``.
- a string with the `identifier name` of a pre-trained model that was user-uploaded to our S3, e.g.: ``dbmdz/bert-base-german-cased``.
- a string with the `identifier name` of a pre-trained model that was user-uploaded to our S3, e.g.: ``dbmdz/bert-base-german-cased``.
- a path to a `directory` containing model weights saved using :func:`~transformers.PreTrainedModel.save_pretrained`, e.g.: ``./my_model_directory/``.
- a path to a `directory` containing model weights saved using :func:`~transformers.PreTrainedModel.save_pretrained`, e.g.: ``./my_model_directory/``.
...
@@ -306,8 +305,8 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin):
...
@@ -306,8 +305,8 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin):
config: (`optional`) one of:
config: (`optional`) one of:
- an instance of a class derived from :class:`~transformers.PretrainedConfig`, or
- an instance of a class derived from :class:`~transformers.PretrainedConfig`, or
- a string valid as input to :func:`~transformers.PretrainedConfig.from_pretrained()`
- a string valid as input to :func:`~transformers.PretrainedConfig.from_pretrained()`
Configuration for the model to use instead of an automatically loaded configuation. Configuration can be automatically loaded when:
Configuration for the model to use instead of an automatically loaded configuation. Configuration can be automatically loaded when:
- the model is a model provided by the library (loaded with the ``shortcut-name`` string of a pretrained model), or
- the model is a model provided by the library (loaded with the ``shortcut-name`` string of a pretrained model), or
- the model was saved using :func:`~transformers.PreTrainedModel.save_pretrained` and is reloaded by suppling the save directory.
- the model was saved using :func:`~transformers.PreTrainedModel.save_pretrained` and is reloaded by suppling the save directory.
- the model is loaded by suppling a local directory as ``pretrained_model_name_or_path`` and a configuration JSON file named `config.json` is found in the directory.
- the model is loaded by suppling a local directory as ``pretrained_model_name_or_path`` and a configuration JSON file named `config.json` is found in the directory.
