Spaces Utils#

gymnasium.spaces.utils.flatten_space(space: Space[Any]) → Box | Dict | Sequence | Tuple | Graph#

gymnasium.spaces.utils.flatten_space(space: Box) → Box

gymnasium.spaces.utils.flatten_space(space: Discrete | MultiBinary | MultiDiscrete) → Box

gymnasium.spaces.utils.flatten_space(space: Tuple) → Box | Tuple

gymnasium.spaces.utils.flatten_space(space: Dict) → Box | Dict

gymnasium.spaces.utils.flatten_space(space: Graph) → Graph

gymnasium.spaces.utils.flatten_space(space: Text) → Box

gymnasium.spaces.utils.flatten_space(space: Sequence) → Sequence

Flatten a space into a space that is as flat as possible.

This function will attempt to flatten space into a single gymnasium.spaces.Box space. However, this might not be possible when space is an instance of gymnasium.spaces.Graph, gymnasium.spaces.Sequence or a compound space that contains a gymnasium.spaces.Graph or gymnasium.spaces.Sequence space. This is equivalent to flatten(), but operates on the space itself. The result for non-graph spaces is always a gymnasium.spaces.Box with flat boundaries. While the result for graph spaces is always a gymnasium.spaces.Graph with Graph.node_space being a Box with flat boundaries and Graph.edge_space being a Box with flat boundaries or None. The box has exactly flatdim() dimensions. Flattening a sample of the original space has the same effect as taking a sample of the flattened space. However, sampling from the flattened space is not necessarily reversible. For example, sampling from a flattened Discrete space is the same as sampling from a Box, and the results may not be integers or one-hot encodings. This may result in errors or non-uniform sampling.

Example::

>>> from gymnasium.spaces import Box
>>> box = Box(0.0, 1.0, shape=(3, 4, 5))
>>> box
Box(3, 4, 5)
>>> flatten_space(box)
Box(60,)
>>> flatten(box, box.sample()) in flatten_space(box)
True

Example that flattens a discrete space::

>>> from gymnasium.spaces import Discrete
>>> discrete = Discrete(5)
>>> flatten_space(discrete)
Box(5,)
>>> flatten(box, box.sample()) in flatten_space(box)
True

Example that recursively flattens a dict::

>>> from gymnasium.spaces import Dict, Discrete, Box
>>> space = Dict({"position": Discrete(2), "velocity": Box(0, 1, shape=(2, 2))})
>>> flatten_space(space)
Box(6,)
>>> flatten(space, space.sample()) in flatten_space(space)
True

Example that flattens a graph:

>>> space = Graph(node_space=Box(low=-100, high=100, shape=(3, 4)), edge_space=Discrete(5))
>>> flatten_space(space)
Graph(Box(-100.0, 100.0, (12,), float32), Box(0, 1, (5,), int64))
>>> flatten(space, space.sample()) in flatten_space(space)
True

Parameters:: space – The space to flatten
Returns:: A flattened Box
Raises:: NotImplementedError – if the space is not defined in gymnasium.spaces.

gymnasium.spaces.utils.flatten(space: Space[T], x: T) → Union[ndarray[Any, dtype[Any]], Dict[str, Any], Tuple[Any, ...], GraphInstance]#

gymnasium.spaces.utils.flatten(space: Box | MultiBinary, x: NDArray[Any]) → NDArray[Any]

gymnasium.spaces.utils.flatten(space: Discrete, x: int64) → ndarray[Any, dtype[int64]]

gymnasium.spaces.utils.flatten(space: MultiDiscrete, x: ndarray[Any, dtype[int64]]) → ndarray[Any, dtype[int64]]

gymnasium.spaces.utils.flatten(space: Tuple, x: tuple[Any, ...]) → tuple[Any, ...] | NDArray[Any]

gymnasium.spaces.utils.flatten(space: Dict, x: dict[str, Any]) → dict[str, Any] | NDArray[Any]

gymnasium.spaces.utils.flatten(space: Graph, x: GraphInstance) → GraphInstance

gymnasium.spaces.utils.flatten(space: Text, x: str) → ndarray[Any, dtype[int32]]

gymnasium.spaces.utils.flatten(space: Sequence, x: tuple[Any, ...]) → tuple[Any, ...]

Flatten a data point from a space.

This is useful when e.g. points from spaces must be passed to a neural network, which only understands flat arrays of floats.

Example usage::

>>> from gymnasium.spaces import Box, Discrete, Tuple
>>> space = Box(0, 1, shape=(3, 5))
>>> flatten(space, space.sample()).shape
(15,)
>>> space = Discrete(4)
>>> flatten(space, 2)
array([0, 0, 1, 0])
>>> space = Tuple((Box(0, 1, shape=(2,)), Box(0, 1, shape=(3,)), Discrete(3)))
>>> example = ((.5, .25), (1., 0., .2), 1)
>>> flatten(space, example)
array([0.5 , 0.25, 1.  , 0.  , 0.2 , 0.  , 1.  , 0.  ])

Parameters:

space – The space that x is flattened by
x – The value to flatten

Returns:

The flattened datapoint –

For gymnasium.spaces.Box and gymnasium.spaces.MultiBinary, this is a flattened array
For gymnasium.spaces.Discrete and gymnasium.spaces.MultiDiscrete, this is a flattened one-hot array of the sample
For gymnasium.spaces.Tuple and gymnasium.spaces.Dict, this is a concatenated array the subspaces (does not support graph subspaces)
For graph spaces, returns GraphInstance where:
- GraphInstance.nodes are n x k arrays
- GraphInstance.edges are either:
  
  m x k arrays
  
  None
- GraphInstance.edge_links are either:
  
  m x 2 arrays
  
  None

Raises:

NotImplementedError – If the space is not defined in gymnasium.spaces.

gymnasium.spaces.utils.flatdim(space: Space[Any]) → int#

gymnasium.spaces.utils.flatdim(space: Box | MultiBinary) → int

gymnasium.spaces.utils.flatdim(space: Discrete) → int

gymnasium.spaces.utils.flatdim(space: MultiDiscrete) → int

gymnasium.spaces.utils.flatdim(space: Tuple) → int

gymnasium.spaces.utils.flatdim(space: Dict) → int

gymnasium.spaces.utils.flatdim(space: Graph)

gymnasium.spaces.utils.flatdim(space: Text) → int

Return the number of dimensions a flattened equivalent of this space would have.

Example usage:

>>> from gymnasium.spaces import Discrete, Dict
>>> space = Dict({"position": Discrete(2), "velocity": Discrete(3)})
>>> flatdim(space)
5

Parameters:

space – The space to return the number of dimensions of the flattened spaces

Returns:

The number of dimensions for the flattened spaces

Raises:

NotImplementedError – if the space is not defined in gym.spaces.
ValueError – if the space cannot be flattened into a gymnasium.spaces.Box

gymnasium.spaces.utils.unflatten(space: Space[T], x: Union[ndarray[Any, dtype[Any]], Dict[str, Any], Tuple[Any, ...], GraphInstance]) → T#

gymnasium.spaces.utils.unflatten(space: Box | MultiBinary, x: NDArray[Any]) → NDArray[Any]

gymnasium.spaces.utils.unflatten(space: Discrete, x: ndarray[Any, dtype[int64]]) → int64

gymnasium.spaces.utils.unflatten(space: MultiDiscrete, x: ndarray[Any, dtype[integer[Any]]]) → ndarray[Any, dtype[integer[Any]]]

gymnasium.spaces.utils.unflatten(space: Tuple, x: NDArray[Any] | tuple[Any, ...]) → tuple[Any, ...]

gymnasium.spaces.utils.unflatten(space: Dict, x: NDArray[Any] | dict[str, Any]) → dict[str, Any]

gymnasium.spaces.utils.unflatten(space: Graph, x: GraphInstance) → GraphInstance

gymnasium.spaces.utils.unflatten(space: Text, x: ndarray[Any, dtype[int32]]) → str

gymnasium.spaces.utils.unflatten(space: Sequence, x: tuple[Any, ...]) → tuple[Any, ...]

Unflatten a data point from a space.

This reverses the transformation applied by flatten(). You must ensure that the space argument is the same as for the flatten() call.

Parameters:

space – The space used to unflatten x
x – The array to unflatten

Returns:

A point with a structure that matches the space.

Raises:

NotImplementedError – if the space is not defined in gymnasium.spaces.