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""" OpenAI GPT configuration """
import logging
from .configuration_utils import PretrainedConfig
logger = logging.getLogger(__name__)
OPENAI_GPT_PRETRAINED_CONFIG_ARCHIVE_MAP = {
"openai-gpt": "https://s3.amazonaws.com/models.huggingface.co/bert/openai-gpt-config.json"
}
[docs]class OpenAIGPTConfig(PretrainedConfig):
"""
This is the configuration class to store the configuration of an :class:`~transformers.OpenAIGPTModel`.
It is used to instantiate an GPT model according to the specified arguments, defining the model
architecture. Instantiating a configuration with the defaults will yield a similar configuration to that of
the `GPT <https://huggingface.co/openai-gpt>`__ architecture from OpenAI.
Configuration objects inherit from :class:`~transformers.PretrainedConfig` and can be used
to control the model outputs. Read the documentation from :class:`~transformers.PretrainedConfig`
for more information.
Args:
vocab_size (:obj:`int`, optional, defaults to 40478):
Vocabulary size of the GPT model. Defines the different tokens that
can be represented by the `inputs_ids` passed to the forward method of :class:`~transformers.CTRLModel`.
n_positions (:obj:`int`, optional, defaults to 512):
The maximum sequence length that this model might ever be used with.
Typically set this to something large just in case (e.g., 512 or 1024 or 2048).
n_ctx (:obj:`int`, optional, defaults to 512):
Dimensionality of the causal mask (usually same as n_positions).
n_embd (:obj:`int`, optional, defaults to 768):
Dimensionality of the embeddings and hidden states.
n_layer (:obj:`int`, optional, defaults to 12):
Number of hidden layers in the Transformer encoder.
n_head (:obj:`int`, optional, defaults to 12):
Number of attention heads for each attention layer in the Transformer encoder.
afn (:obj:`str` or :obj:`function`, optional, defaults to "gelu"):
The non-linear activation function (function or string) in the encoder and pooler.
If string, "gelu", "relu", "swish" and "gelu_new" are supported.
resid_pdrop (:obj:`float`, optional, defaults to 0.1):
The dropout probability for all fully connected layers in the embeddings, encoder, and pooler.
embd_pdrop (:obj:`int`, optional, defaults to 0.1):
The dropout ratio for the embeddings.
attn_pdrop (:obj:`float`, optional, defaults to 0.1):
The dropout ratio for the attention.
layer_norm_epsilon (:obj:`float`, optional, defaults to 1e-5):
The epsilon to use in the layer normalization layers
initializer_range (:obj:`float`, optional, defaults to 0.02):
The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
predict_special_tokens (:obj:`boolean`, optional, defaults to :obj:`True`):
Whether special tokens should be predicted when the model is has a language modeling head.
summary_type (:obj:`string`, optional, defaults to "cls_index"):
Argument used when doing sequence summary. Used in for the multiple choice head in
:class:`~transformers.OpenAIGPTDoubleHeadsModel`.
Is one of the following options:
- 'last' => take the last token hidden state (like XLNet)
- 'first' => take the first token hidden state (like Bert)
- 'mean' => take the mean of all tokens hidden states
- 'cls_index' => supply a Tensor of classification token position (GPT/GPT-2)
- 'attn' => Not implemented now, use multi-head attention
summary_use_proj (:obj:`boolean`, optional, defaults to :obj:`True`):
Argument used when doing sequence summary. Used in for the multiple choice head in
:class:`~transformers.OpenAIGPTDoubleHeadsModel`.
Add a projection after the vector extraction
summary_activation (:obj:`string` or :obj:`None`, optional, defaults to :obj:`None`):
Argument used when doing sequence summary. Used in for the multiple choice head in
:class:`~transformers.OpenAIGPTDoubleHeadsModel`.
'tanh' => add a tanh activation to the output, Other => no activation.
summary_proj_to_labels (:obj:`boolean`, optional, defaults to :obj:`True`):
Argument used when doing sequence summary. Used in for the multiple choice head in
:class:`~transformers.OpenAIGPTDoubleHeadsModel`.
If True, the projection outputs to config.num_labels classes (otherwise to hidden_size). Default: False.
summary_first_dropout (:obj:`float`, optional, defaults to 0.1):
Argument used when doing sequence summary. Used in for the multiple choice head in
:class:`~transformers.OpenAIGPTDoubleHeadsModel`.
Add a dropout before the projection and activation
Example::
from transformers import OpenAIGPTConfig, OpenAIGPTModel
# Initializing a GPT configuration
configuration = OpenAIGPTConfig()
# Initializing a model from the configuration
model = OpenAIGPTModel(configuration)
# Accessing the model configuration
configuration = model.config
Attributes:
pretrained_config_archive_map (Dict[str, str]):
A dictionary containing all the available pre-trained checkpoints.
"""
pretrained_config_archive_map = OPENAI_GPT_PRETRAINED_CONFIG_ARCHIVE_MAP
model_type = "openai-gpt"
def __init__(
self,
vocab_size=40478,
n_positions=512,
n_ctx=512,
n_embd=768,
n_layer=12,
n_head=12,
afn="gelu",
resid_pdrop=0.1,
embd_pdrop=0.1,
attn_pdrop=0.1,
layer_norm_epsilon=1e-5,
initializer_range=0.02,
predict_special_tokens=True,
summary_type="cls_index",
summary_use_proj=True,
summary_activation=None,
summary_proj_to_labels=True,
summary_first_dropout=0.1,
**kwargs
):
super().__init__(**kwargs)
self.vocab_size = vocab_size
self.n_ctx = n_ctx
self.n_positions = n_positions
self.n_embd = n_embd
self.n_layer = n_layer
self.n_head = n_head
self.afn = afn
self.resid_pdrop = resid_pdrop
self.embd_pdrop = embd_pdrop
self.attn_pdrop = attn_pdrop
self.layer_norm_epsilon = layer_norm_epsilon
self.initializer_range = initializer_range
self.predict_special_tokens = predict_special_tokens
self.summary_type = summary_type
self.summary_use_proj = summary_use_proj
self.summary_activation = summary_activation
self.summary_first_dropout = summary_first_dropout
self.summary_proj_to_labels = summary_proj_to_labels
@property
def max_position_embeddings(self):
return self.n_positions
@property
def hidden_size(self):
return self.n_embd
@property
def num_attention_heads(self):
return self.n_head
@property
def num_hidden_layers(self):
return self.n_layer