MaskedLM
classkeras_hub.models.MaskedLM()
Base class for masked language modeling tasks.
MaskedLM
tasks wrap a keras_hub.models.Backbone
and
a keras_hub.models.Preprocessor
to create a model that can be used for
unsupervised fine-tuning with a masked language modeling loss.
When calling fit()
, all input will be tokenized, and random tokens in
the input sequence will be masked. These positions of these masked tokens
will be fed as an additional model input, and the original value of the
tokens predicted by the model outputs.
All MaskedLM
tasks include a from_preset()
constructor which can be used
to load a pre-trained config and weights.
Example
# Load a Bert MaskedLM with pre-trained weights.
masked_lm = keras_hub.models.MaskedLM.from_preset(
"bert_base_en",
)
masked_lm.fit(train_ds)
from_preset
methodMaskedLM.from_preset(preset, load_weights=True, **kwargs)
Instantiate a keras_hub.models.Task
from a model preset.
A preset is a directory of configs, weights and other file assets used
to save and load a pre-trained model. The preset
can be passed as
one of:
'bert_base_en'
'kaggle://user/bert/keras/bert_base_en'
'hf://user/bert_base_en'
'./bert_base_en'
For any Task
subclass, you can run cls.presets.keys()
to list all
built-in presets available on the class.
This constructor can be called in one of two ways. Either from a task
specific base class like keras_hub.models.CausalLM.from_preset()
, or
from a model class like keras_hub.models.BertTextClassifier.from_preset()
.
If calling from the a base class, the subclass of the returning object
will be inferred from the config in the preset directory.
Arguments
True
, saved weights will be loaded into
the model architecture. If False
, all weights will be
randomly initialized.Examples
# Load a Gemma generative task.
causal_lm = keras_hub.models.CausalLM.from_preset(
"gemma_2b_en",
)
# Load a Bert classification task.
model = keras_hub.models.TextClassifier.from_preset(
"bert_base_en",
num_classes=2,
)
compile
methodMaskedLM.compile(optimizer="auto", loss="auto", weighted_metrics="auto", **kwargs)
Configures the MaskedLM
task for training.
The MaskedLM
task extends the default compilation signature of
keras.Model.compile
with defaults for optimizer
, loss
, and
weighted_metrics
. To override these defaults, pass any value
to these arguments during compilation.
Note that because training inputs include padded tokens which are
excluded from the loss, it is almost always a good idea to compile with
weighted_metrics
and not metrics
.
Arguments
"auto"
, an optimizer name, or a keras.Optimizer
instance. Defaults to "auto"
, which uses the default optimizer
for the given model and task. See keras.Model.compile
and
keras.optimizers
for more info on possible optimizer
values."auto"
, a loss name, or a keras.losses.Loss
instance.
Defaults to "auto"
, where a
keras.losses.SparseCategoricalCrossentropy
loss will be
applied for the token classification MaskedLM
task. See
keras.Model.compile
and keras.losses
for more info on
possible loss
values."auto"
, or a list of metrics to be evaluated by
the model during training and testing. Defaults to "auto"
,
where a keras.metrics.SparseCategoricalAccuracy
will be
applied to track the accuracy of the model at guessing masked
token values. See keras.Model.compile
and keras.metrics
for
more info on possible weighted_metrics
values.keras.Model.compile
for a full list of arguments
supported by the compile method.save_to_preset
methodMaskedLM.save_to_preset(preset_dir)
Save task to a preset directory.
Arguments
preprocessor
propertykeras_hub.models.MaskedLM.preprocessor
A keras_hub.models.Preprocessor
layer used to preprocess input.
backbone
propertykeras_hub.models.MaskedLM.backbone
A keras_hub.models.Backbone
model with the core architecture.