A conditional accumulator for aggregating gradients.
Inherits From: ConditionalAccumulatorBase
tf.compat.v1.ConditionalAccumulator(
dtype, shape=None, shared_name=None, name='conditional_accumulator',
reduction_type='MEAN'
)
Up-to-date gradients (i.e., time step at which gradient was computed is
equal to the accumulator's time step) are added to the accumulator.
Extraction of the average gradient is blocked until the required number of
gradients has been accumulated.
Args |
|---|
dtype
|
Datatype of the accumulated gradients.
|
shape
|
Shape of the accumulated gradients.
|
shared_name
|
Optional. If non-empty, this accumulator will be shared under
the given name across multiple sessions.
|
name
|
Optional name for the accumulator.
|
reduction_type
|
Reduction type to use when taking the gradient.
|
Attributes |
|---|
accumulator_ref
|
The underlying accumulator reference.
|
dtype
|
The datatype of the gradients accumulated by this accumulator.
|
name
|
The name of the underlying accumulator.
|
Methods
apply_grad
View source
apply_grad(
grad, local_step=0, name=None
)
Attempts to apply a gradient to the accumulator.
The attempt is silently dropped if the gradient is stale, i.e., local_step
is less than the accumulator's global time step.
| Args |
|---|
grad
|
The gradient tensor to be applied.
|
local_step
|
Time step at which the gradient was computed.
|
name
|
Optional name for the operation.
|
| Returns |
|---|
|
The operation that (conditionally) applies a gradient to the accumulator.
|
| Raises |
|---|
ValueError
|
If grad is of the wrong shape
|
num_accumulated
View source
num_accumulated(
name=None
)
Number of gradients that have currently been aggregated in accumulator.
| Args |
|---|
name
|
Optional name for the operation.
|
| Returns |
|---|
|
Number of accumulated gradients currently in accumulator.
|
set_global_step
View source
set_global_step(
new_global_step, name=None
)
Sets the global time step of the accumulator.
The operation logs a warning if we attempt to set to a time step that is
lower than the accumulator's own time step.
| Args |
|---|
new_global_step
|
Value of new time step. Can be a variable or a constant
|
name
|
Optional name for the operation.
|
| Returns |
|---|
|
Operation that sets the accumulator's time step.
|
take_grad
View source
take_grad(
num_required, name=None
)
Attempts to extract the average gradient from the accumulator.
The operation blocks until sufficient number of gradients have been
successfully applied to the accumulator.
Once successful, the following actions are also triggered:
- Counter of accumulated gradients is reset to 0.
- Aggregated gradient is reset to 0 tensor.
- Accumulator's internal time step is incremented by 1.
| Args |
|---|
num_required
|
Number of gradients that needs to have been aggregated
|
name
|
Optional name for the operation
|
| Returns |
|---|
|
A tensor holding the value of the average gradient.
|
| Raises |
|---|
InvalidArgumentError
|
If num_required < 1
|
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