View source on GitHub |
Swaps model weights and EMA weights before and after evaluation.
Inherits From: Callback
tf.keras.callbacks.SwapEMAWeights(
swap_on_epoch=False
)
This callbacks replaces the model's weight values with the values of the optimizer's EMA weights (the exponential moving average of the past model weights values, implementing "Polyak averaging") before model evaluation, and restores the previous weights after evaluation.
The SwapEMAWeights
callback is to be used in conjunction with
an optimizer that sets use_ema=True
.
Note that the weights are swapped in-place in order to save memory. The behavior is undefined if you modify the EMA weights or model weights in other callbacks.
Example:
# Remember to set `use_ema=True` in the optimizer
optimizer = SGD(use_ema=True)
model.compile(optimizer=optimizer, loss=..., metrics=...)
# Metrics will be computed with EMA weights
model.fit(X_train, Y_train, callbacks=[SwapEMAWeights()])
# If you want to save model checkpoint with EMA weights, you can set
# `swap_on_epoch=True` and place ModelCheckpoint after SwapEMAWeights.
model.fit(
X_train,
Y_train,
callbacks=[SwapEMAWeights(swap_on_epoch=True), ModelCheckpoint(...)]
)
Args | |
---|---|
swap_on_epoch
|
whether to perform swapping at on_epoch_begin()
and on_epoch_end() . This is useful if you want to use
EMA weights for other callbacks such as ModelCheckpoint .
Defaults to False .
|
Attributes | |
---|---|
model
|
Methods
on_batch_begin
on_batch_begin(
batch, logs=None
)
A backwards compatibility alias for on_train_batch_begin
.
on_batch_end
on_batch_end(
batch, logs=None
)
A backwards compatibility alias for on_train_batch_end
.
on_epoch_begin
on_epoch_begin(
epoch, logs=None
)
Called at the start of an epoch.
Subclasses should override for any actions to run. This function should only be called during TRAIN mode.
Args | |
---|---|
epoch
|
Integer, index of epoch. |
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_epoch_end
on_epoch_end(
epoch, logs=None
)
Called at the end of an epoch.
Subclasses should override for any actions to run. This function should only be called during TRAIN mode.
Args | |
---|---|
epoch
|
Integer, index of epoch. |
logs
|
Dict, metric results for this training epoch, and for the
validation epoch if validation is performed. Validation result
keys are prefixed with val_ . For training epoch, the values of
the Model 's metrics are returned. Example:
{'loss': 0.2, 'accuracy': 0.7} .
|
on_predict_batch_begin
on_predict_batch_begin(
batch, logs=None
)
Called at the beginning of a batch in predict
methods.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_predict_batch_end
on_predict_batch_end(
batch, logs=None
)
Called at the end of a batch in predict
methods.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Aggregated metric results up until this batch. |
on_predict_begin
on_predict_begin(
logs=None
)
Called at the beginning of prediction.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_predict_end
on_predict_end(
logs=None
)
Called at the end of prediction.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_test_batch_begin
on_test_batch_begin(
batch, logs=None
)
Called at the beginning of a batch in evaluate
methods.
Also called at the beginning of a validation batch in the fit
methods, if validation data is provided.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_test_batch_end
on_test_batch_end(
batch, logs=None
)
Called at the end of a batch in evaluate
methods.
Also called at the end of a validation batch in the fit
methods, if validation data is provided.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Aggregated metric results up until this batch. |
on_test_begin
on_test_begin(
logs=None
)
Called at the beginning of evaluation or validation.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_test_end
on_test_end(
logs=None
)
Called at the end of evaluation or validation.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently the output of the last call to
on_test_batch_end() is passed to this argument for this method
but that may change in the future.
|
on_train_batch_begin
on_train_batch_begin(
batch, logs=None
)
Called at the beginning of a training batch in fit
methods.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_train_batch_end
on_train_batch_end(
batch, logs=None
)
Called at the end of a training batch in fit
methods.
Subclasses should override for any actions to run.
Note that if the steps_per_execution
argument to compile
in
Model
is set to N
, this method will only be called every
N
batches.
Args | |
---|---|
batch
|
Integer, index of batch within the current epoch. |
logs
|
Dict. Aggregated metric results up until this batch. |
on_train_begin
on_train_begin(
logs=None
)
Called at the beginning of training.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently no data is passed to this argument for this method but that may change in the future. |
on_train_end
on_train_end(
logs=None
)
Called at the end of training.
Subclasses should override for any actions to run.
Args | |
---|---|
logs
|
Dict. Currently the output of the last call to
on_epoch_end() is passed to this argument for this method but
that may change in the future.
|
set_model
set_model(
model
)
set_params
set_params(
params
)