tf_agents.bandits.policies.constraints.NeuralConstraint

Class for representing a trainable constraint using a neural network.

Inherits From: BaseConstraint

tf_agents.bandits.policies.constraints.NeuralConstraint(
    time_step_spec: tf_agents.typing.types.TimeStep,
    action_spec: tf_agents.typing.types.BoundedTensorSpec,
    constraint_network: Optional[tf_agents.typing.types.Network],
    error_loss_fn: tf_agents.typing.types.LossFn = tf.compat.v1.losses.mean_squared_error,
    name: Optional[Text] = 'NeuralConstraint'
)

This constraint class uses a neural network to compute the action feasibility. In this case, the loss function needs to be exposed for training the neural network weights, typically done by the agent that uses this constraint.

Args
time_step_spec	A TimeStep spec of the expected time_steps.
action_spec	A nest of BoundedTensorSpec representing the actions.
constraint_network	An instance of tf_agents.network.Network used to provide estimates of action feasibility. The input structure should be consistent with the observation_spec. If the constraint network is not available at construction time, it can be set later on using the constraint_network setter.
error_loss_fn	A function for computing the loss used to train the constraint network. The default is tf.losses.mean_squared_error.
name	Python str name of this agent. All variables in this module will fall under that name. Defaults to the class name.

Attributes
constraint_network
observation_spec

Methods

compute_loss

View source

compute_loss(
    observations: tf_agents.typing.types.NestedTensor,
    actions: tf_agents.typing.types.NestedTensor,
    rewards: tf_agents.typing.types.Tensor,
    weights: Optional[types.Float] = None,
    training: bool = False
) -> tf_agents.typing.types.Tensor

Computes loss for training the constraint network.

Args
observations	A batch of observations.
actions	A batch of actions.
rewards	A batch of rewards.
weights	Optional scalar or elementwise (per-batch-entry) importance weights. The output batch loss will be scaled by these weights, and the final scalar loss is the mean of these values.
training	Whether the loss is being used for training.

Returns
loss	A Tensor containing the loss for the training step.

initialize

View source

initialize()

Returns an op to initialize the constraint.

__call__

View source

__call__(
    observation, actions=None
)

Returns the probability of input actions being feasible.