tf.compat.v1.train.MomentumOptimizer

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Optimizer that implements the Momentum algorithm.

Inherits From: Optimizer

tf.compat.v1.train.MomentumOptimizer(
    learning_rate, momentum, use_locking=False, name='Momentum', use_nesterov=False
)

Computes (if use_nesterov = False):

accumulation = momentum * accumulation + gradient
variable -= learning_rate * accumulation

Note that in the dense version of this algorithm, accumulation is updated and applied regardless of a gradient's value, whereas the sparse version (when the gradient is an IndexedSlices, typically because of tf.gather or an embedding) only updates variable slices and corresponding accumulation terms when that part of the variable was used in the forward pass.

Args:

Methods

apply_gradients

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apply_gradients(
    grads_and_vars, global_step=None, name=None
)

Apply gradients to variables.

This is the second part of minimize(). It returns an Operation that applies gradients.

Args:

Returns:

An Operation that applies the specified gradients. If global_step was not None, that operation also increments global_step.

Raises:

compute_gradients

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compute_gradients(
    loss, var_list=None, gate_gradients=GATE_OP, aggregation_method=None,
    colocate_gradients_with_ops=False, grad_loss=None
)

Compute gradients of loss for the variables in var_list.

This is the first part of minimize(). It returns a list of (gradient, variable) pairs where "gradient" is the gradient for "variable". Note that "gradient" can be a Tensor, an IndexedSlices, or None if there is no gradient for the given variable.

Args:

Returns:

A list of (gradient, variable) pairs. Variable is always present, but gradient can be None.

Raises:

Eager Compatibility

When eager execution is enabled, gate_gradients, aggregation_method, and colocate_gradients_with_ops are ignored.

get_name

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get_name()

get_slot

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get_slot(
    var, name
)

Return a slot named name created for var by the Optimizer.

Some Optimizer subclasses use additional variables. For example Momentum and Adagrad use variables to accumulate updates. This method gives access to these Variable objects if for some reason you need them.

Use get_slot_names() to get the list of slot names created by the Optimizer.

Args:

Returns:

The Variable for the slot if it was created, None otherwise.

get_slot_names

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get_slot_names()

Return a list of the names of slots created by the Optimizer.

See get_slot().

Returns:

A list of strings.

minimize

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minimize(
    loss, global_step=None, var_list=None, gate_gradients=GATE_OP,
    aggregation_method=None, colocate_gradients_with_ops=False, name=None,
    grad_loss=None
)

Add operations to minimize loss by updating var_list.

This method simply combines calls compute_gradients() and apply_gradients(). If you want to process the gradient before applying them call compute_gradients() and apply_gradients() explicitly instead of using this function.

Args:

Returns:

An Operation that updates the variables in var_list. If global_step was not None, that operation also increments global_step.

Raises:

Eager Compatibility

When eager execution is enabled, loss should be a Python function that takes no arguments and computes the value to be minimized. Minimization (and gradient computation) is done with respect to the elements of var_list if not None, else with respect to any trainable variables created during the execution of the loss function. gate_gradients, aggregation_method, colocate_gradients_with_ops and grad_loss are ignored when eager execution is enabled.

variables

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variables()

A list of variables which encode the current state of Optimizer.

Includes slot variables and additional global variables created by the optimizer in the current default graph.

Returns:

A list of variables.

Class Variables