rlgt.environments.global_environments.GlobalFlipEnvironment

class documentation

class GlobalFlipEnvironment(GraphEnvironment):

Constructor: GlobalFlipEnvironment(graph_invariant, graph_order, episode_length, flip_only, ...)

This class inherits from GraphEnvironment and models a graph building game for constructing 2-edge-colored looped complete graphs. In this environment, all edges (resp. arcs) are initially fully colored in some manner, and at each step, any edge (resp. arc) can be potentially flipped. Users can configure the graph order, whether the graphs are directed or undirected, whether loops are allowed, and the mechanism for generating the initial fully colored graphs, which can be deterministic or nondeterministic.

The RL tasks in this environment are continuing. The total number of actions to be performed, i.e., the episode length, is configurable.

Each state is represented by a binary numpy.ndarray vector of type numpy.uint8 that encodes the current graph in one of the two flattened formats with color numbers. The edge ordering (row-major or clockwise) is configurable by the user at initialization and remains fixed.

The environment supports two modes of operation controlled by the flip_only parameter. If flip_only is False (the default), each action is a numpy.int32 integer between 0 and 2 * flattened_length - 1. In this case, for an action a, a % flattened_length gives the index of the edge (resp. arc) to potentially flip, and a // flattened_length is a binary value indicating whether the edge should actually be flipped (1) or left unchanged (0). If flip_only is True, each action is a numpy.int32 integer between 0 and flattened_length - 1, specifying the index of the edge (resp. arc) that must be flipped.

Method	`__init__`	This constructor initializes an instance of the `GlobalFlipEnvironment` class.
Method	`episode_length.setter`	This setter allows the user to potentially reconfigure the episode length between two independent batches of episodes. It should not be used while a batch of episodes is currently in progress.
Method	`state_batch_to_graph_batch`	This abstract method must be implemented by any concrete subclass. It extracts the batch of underlying graphs corresponding to a provided batch of states. Implementations must return a `Graph` object containing the graphs corresponding to each row in ...
Instance Variable	`initial_graph_generator`	A `GraphGenerator` function that defines how the underlying fully colored graphs are generated for the initial states. This attribute may be reconfigured between independent batches of episodes.
Property	`action_mask`	This abstract property must be implemented by any concrete subclass. It must return `None` if no episodes are currently being run in parallel, or if every action is available in every current state. Otherwise, it must return a two-dimensional ...
Property	`action_number`	This abstract property must be implemented by any concrete subclass. It must return the total number of distinct actions that can be executed in the environment, as a positive `int`.
Property	`episode_length`	This abstract property must be implemented by any concrete subclass. It must return the predetermined common length of all episodes run in parallel, i.e., the total number of actions executed in each episode, as a positive ...
Property	`is_continuing`	This abstract property must be implemented by any concrete subclass. It must return a `bool` indicating whether the environment is continuing (`True`) or episodic (`False`).
Property	`state_dtype`	This abstract property must be implemented by any concrete subclass. It must return the data type of the one-dimensional `numpy.ndarray` vectors that represent states, as a `numpy.dtype`.
Property	`state_length`	This abstract property must be implemented by any concrete subclass. It must return the number of entries in each state vector, i.e., the length of the one-dimensional `numpy.ndarray` vectors that represent states, as a positive ...
Method	`_initialize_batch`	This abstract method must be implemented by any concrete subclass. It must initialize a batch of episodes of the specified size and update the `_state_batch` and `_status` attributes so that they represent the newly initialized batch.
Method	`_transition_batch`	This abstract method must be implemented by any concrete subclass. It must apply a batch of actions to the current batch of states and update the `_state_batch` and `_status` attributes to reflect the resulting states and the updated batch status...
Instance Variable	`_allow_loops`	A `bool` indicating whether loops are allowed in the graphs to be constructed.
Instance Variable	`_episode_length`	A positive `int` specifying the episode length, i.e., the total number of actions in each episode.
Instance Variable	`_flattened_length`	A positive `int` equal to the flattened length of the graphs to be constructed.
Instance Variable	`_flattened_ordering`	An item of the `FlattenedOrdering` enumeration specifying the edge (resp. arc) ordering (row-major or clockwise).
Instance Variable	`_flip_only`	A `bool` specifying whether the selected edges (resp. arcs) must be flipped.
Instance Variable	`_is_directed`	A `bool` indicating whether the graphs to be constructed are directed or undirected.
Instance Variable	`_state_batch`	See `GraphEnvironment._state_batch`.
Instance Variable	`_status`	See `GraphEnvironment._status`.
Instance Variable	`_step_count`	Either `None` or a nonnegative `int` counting how many actions have been executed in the current batch of episodes. When `_step_count` equals `_episode_length`, the episode has reached a final state. This attribute is updated after each call to ...

Inherited from GraphEnvironment:

Method	`reset_batch`	This method initializes a batch of episodes of a specified size and returns the resulting batch of states, the corresponding values of the selected graph invariant (if computed), and the status of the batch of episodes...
Method	`state_to_graph`	This method extracts the underlying graph corresponding to a single state.
Method	`step_batch`	This method applies a batch of actions to the current batch of episodes and returns the resulting batch of states, the corresponding values of the selected graph invariant (if computed), and the updated status of the batch...
Instance Variable	`sparse_setting`	A `bool` indicating whether the graph invariant values should be computed only for the final batch of actions.
Instance Variable	`__graph_batch`	Either `None` or a `Graph` object representing the current batch of underlying graphs. This attribute is updated only when required by the sparse setting.
Instance Variable	`__graph_invariant`	A `GraphInvariant` function specifying the graph invariant to be maximized.
Instance Variable	`__graph_invariant_batch`	Either `None` or a one-dimensional `numpy.ndarray` of type `numpy.float32` containing the current batch of graph invariant values. As with `__graph_batch`, this attribute is updated only when required by the sparse setting.
Instance Variable	`__graph_invariant_diff`	Either `None`, indicating that graph invariant values are always computed directly using `__graph_invariant`, or a `GraphInvariantDiff` function used to incrementally update invariant values after state transitions.

def __init__(self, graph_invariant: GraphInvariant, graph_order: int, episode_length: int | None = None, flip_only: bool = False, flattened_ordering: FlattenedOrdering = FlattenedOrdering.ROW_MAJOR, is_directed: bool = False, allow_loops: bool = False, initial_graph_generator: GraphGenerator | None = None, graph_invariant_diff: GraphInvariantDiff | None = None, sparse_setting: bool = False): ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.__init__

This constructor initializes an instance of the GlobalFlipEnvironment class.

Parameters
graph_invariant:`GraphInvariant`	A `GraphInvariant` function that computes the graph invariant values associated with a batch of underlying graphs. These values are the quantities to be maximized by the environment.
graph_order:`int`	A positive `int` (not below 2) that represents the graph order of the graphs to be constructed.
episode_length:`int \| None`	Either `None`, or a positive `int` specifying the number of actions in each episode. If `None`, the episode length defaults to the flattened length of the graphs to be constructed. The default value is `None`.
flip_only:`bool`	A `bool` specifying whether the selected edges (resp. arcs) must be flipped. The default value is `False`.
flattened_ordering:`FlattenedOrdering`	An item of the `FlattenedOrdering` enumeration specifying whether the edges (resp. arcs) are ordered row-major or clockwise. The default value is `FlattenedOrdering.ROW_MAJOR`.
is_directed:`bool`	A `bool` indicating whether the graphs to be constructed are directed. The default value is `False`.
allow_loops:`bool`	A `bool` indicating whether loops are allowed in the graphs to be constructed. The default value is `False`.
initial_graph_generator:`GraphGenerator \| None`	Either `None` or a `GraphGenerator` function that determines how the initial fully colored graphs are generated for the batch of initial states. If `None`, all edges (resp. arcs) in all graphs are initially colored with color 0. The default value is `None`.
graph_invariant_diff:`GraphInvariantDiff \| None`	Either `None`, indicating that graph invariant values are always computed directly using `graph_invariant`, or a `GraphInvariantDiff` function that computes element-wise differences of the graph invariant values when the environment transitions from one batch of underlying graphs to another. The default value is `None`.
sparse_setting:`bool`	A `bool` indicating whether the sparse setting is enabled. If set to `True`, the graph invariant values are computed only for the final batch of actions. Otherwise, the graph invariant values are computed after every batch of actions. The default value is `False`.

@episode_length.setter

def episode_length(self, episode_length: int): ¶

This setter allows the user to potentially reconfigure the episode length between two independent batches of episodes. It should not be used while a batch of episodes is currently in progress.

Parameters
episode_length:`int`	A positive `int` specifying the new episode length.

def state_batch_to_graph_batch(self, state_batch: np.ndarray) -> Graph: ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.state_batch_to_graph_batch

This abstract method must be implemented by any concrete subclass. It extracts the batch of underlying graphs corresponding to a provided batch of states. Implementations must return a Graph object containing the graphs corresponding to each row in state_batch, preserving the row order. This method must be pure and must not modify any attributes of the class instance.

Parameters
state_batch:`np.ndarray`	A two-dimensional `numpy.ndarray` whose rows represent individual states from which the underlying graphs are to be extracted.

Returns
`Graph`	A `Graph` object representing the extracted batch of graphs.

initial_graph_generator: GraphGenerator = ¶

A GraphGenerator function that defines how the underlying fully colored graphs are generated for the initial states. This attribute may be reconfigured between independent batches of episodes.

@property

action_mask: np.ndarray | None = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.action_mask

This abstract property must be implemented by any concrete subclass. It must return None if no episodes are currently being run in parallel, or if every action is available in every current state. Otherwise, it must return a two-dimensional numpy.ndarray matrix a of type bool whose entry a[i, j] is True if and only if action j is available in the current state of the i-th episode.

@property

action_number: int = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.action_number

This abstract property must be implemented by any concrete subclass. It must return the total number of distinct actions that can be executed in the environment, as a positive int.

@property

episode_length: int = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.episode_length

This abstract property must be implemented by any concrete subclass. It must return the predetermined common length of all episodes run in parallel, i.e., the total number of actions executed in each episode, as a positive int.

@property

is_continuing: bool = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.is_continuing

This abstract property must be implemented by any concrete subclass. It must return a bool indicating whether the environment is continuing (True) or episodic (False).

@property

state_dtype: np.dtype = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.state_dtype

This abstract property must be implemented by any concrete subclass. It must return the data type of the one-dimensional numpy.ndarray vectors that represent states, as a numpy.dtype.

@property

state_length: int = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment.state_length

This abstract property must be implemented by any concrete subclass. It must return the number of entries in each state vector, i.e., the length of the one-dimensional numpy.ndarray vectors that represent states, as a positive int.

def _initialize_batch(self, batch_size: int): ¶

overrides rlgt.environments.graph_environment.GraphEnvironment._initialize_batch

This abstract method must be implemented by any concrete subclass. It must initialize a batch of episodes of the specified size and update the _state_batch and _status attributes so that they represent the newly initialized batch.

Parameters
batch_size:`int`	The number of episodes to initialize in the batch, given as a positive `int`.

def _transition_batch(self, action_batch: np.ndarray): ¶

overrides rlgt.environments.graph_environment.GraphEnvironment._transition_batch

This abstract method must be implemented by any concrete subclass. It must apply a batch of actions to the current batch of states and update the _state_batch and _status attributes to reflect the resulting states and the updated batch status. Implementations may also update additional subclass-specific attributes as required.

Parameters
action_batch:`np.ndarray`	A one-dimensional `numpy.ndarray` of type `numpy.int32` containing the actions to be applied. The length of `action_batch` must match the number of states in `_state_batch`.

_allow_loops: bool = ¶

A bool indicating whether loops are allowed in the graphs to be constructed.

_episode_length: int = ¶

A positive int specifying the episode length, i.e., the total number of actions in each episode.

_flattened_length: int = ¶

A positive int equal to the flattened length of the graphs to be constructed.

_flattened_ordering: FlattenedOrdering = ¶

An item of the FlattenedOrdering enumeration specifying the edge (resp. arc) ordering (row-major or clockwise).

_flip_only: bool = ¶

A bool specifying whether the selected edges (resp. arcs) must be flipped.

_is_directed: bool = ¶

A bool indicating whether the graphs to be constructed are directed or undirected.

_state_batch = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment._state_batch

See GraphEnvironment._state_batch.

_status = ¶

overrides rlgt.environments.graph_environment.GraphEnvironment._status

See GraphEnvironment._status.

_step_count: int | None = ¶

Either None or a nonnegative int counting how many actions have been executed in the current batch of episodes. When _step_count equals _episode_length, the episode has reached a final state. This attribute is updated after each call to GraphEnvironment.reset_batch or GraphEnvironment.step_batch.