ray/rllib/models/preprocessors.py

393 lines
14 KiB
Python

from collections import OrderedDict
import logging
import numpy as np
import gym
from typing import Any, List
from ray.rllib.utils.annotations import override, PublicAPI, DeveloperAPI
from ray.rllib.utils.spaces.repeated import Repeated
from ray.rllib.utils.typing import TensorType
from ray.rllib.utils.images import resize
from ray.rllib.utils.spaces.space_utils import convert_element_to_space_type
ATARI_OBS_SHAPE = (210, 160, 3)
ATARI_RAM_OBS_SHAPE = (128,)
# Only validate env observations vs the observation space every n times in a
# Preprocessor.
OBS_VALIDATION_INTERVAL = 100
logger = logging.getLogger(__name__)
@PublicAPI
class Preprocessor:
"""Defines an abstract observation preprocessor function.
Attributes:
shape (List[int]): Shape of the preprocessed output.
"""
@PublicAPI
def __init__(self, obs_space: gym.Space, options: dict = None):
_legacy_patch_shapes(obs_space)
self._obs_space = obs_space
if not options:
from ray.rllib.models.catalog import MODEL_DEFAULTS
self._options = MODEL_DEFAULTS.copy()
else:
self._options = options
self.shape = self._init_shape(obs_space, self._options)
self._size = int(np.product(self.shape))
self._i = 0
self._obs_for_type_matching = self._obs_space.sample()
@PublicAPI
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
"""Returns the shape after preprocessing."""
raise NotImplementedError
@PublicAPI
def transform(self, observation: TensorType) -> np.ndarray:
"""Returns the preprocessed observation."""
raise NotImplementedError
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
"""Alternative to transform for more efficient flattening."""
array[offset : offset + self._size] = self.transform(observation)
def check_shape(self, observation: Any) -> None:
"""Checks the shape of the given observation."""
if self._i % OBS_VALIDATION_INTERVAL == 0:
# Convert lists to np.ndarrays.
if type(observation) is list and isinstance(
self._obs_space, gym.spaces.Box
):
observation = np.array(observation).astype(np.float32)
if not self._obs_space.contains(observation):
observation = convert_element_to_space_type(
observation, self._obs_for_type_matching
)
try:
if not self._obs_space.contains(observation):
raise ValueError(
"Observation ({} dtype={}) outside given space ({})!",
observation,
observation.dtype
if isinstance(self._obs_space, gym.spaces.Box)
else None,
self._obs_space,
)
except AttributeError:
raise ValueError(
"Observation for a Box/MultiBinary/MultiDiscrete space "
"should be an np.array, not a Python list.",
observation,
)
self._i += 1
@property
@PublicAPI
def size(self) -> int:
return self._size
@property
@PublicAPI
def observation_space(self) -> gym.Space:
obs_space = gym.spaces.Box(-1.0, 1.0, self.shape, dtype=np.float32)
# Stash the unwrapped space so that we can unwrap dict and tuple spaces
# automatically in modelv2.py
classes = (
DictFlatteningPreprocessor,
OneHotPreprocessor,
RepeatedValuesPreprocessor,
TupleFlatteningPreprocessor,
)
if isinstance(self, classes):
obs_space.original_space = self._obs_space
return obs_space
@DeveloperAPI
class GenericPixelPreprocessor(Preprocessor):
"""Generic image preprocessor.
Note: for Atari games, use config {"preprocessor_pref": "deepmind"}
instead for deepmind-style Atari preprocessing.
"""
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
self._grayscale = options.get("grayscale")
self._zero_mean = options.get("zero_mean")
self._dim = options.get("dim")
if self._grayscale:
shape = (self._dim, self._dim, 1)
else:
shape = (self._dim, self._dim, 3)
return shape
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
"""Downsamples images from (210, 160, 3) by the configured factor."""
self.check_shape(observation)
scaled = observation[25:-25, :, :]
if self._dim < 84:
scaled = resize(scaled, height=84, width=84)
# OpenAI: Resize by half, then down to 42x42 (essentially mipmapping).
# If we resize directly we lose pixels that, when mapped to 42x42,
# aren't close enough to the pixel boundary.
scaled = resize(scaled, height=self._dim, width=self._dim)
if self._grayscale:
scaled = scaled.mean(2)
scaled = scaled.astype(np.float32)
# Rescale needed for maintaining 1 channel
scaled = np.reshape(scaled, [self._dim, self._dim, 1])
if self._zero_mean:
scaled = (scaled - 128) / 128
else:
scaled *= 1.0 / 255.0
return scaled
@DeveloperAPI
class AtariRamPreprocessor(Preprocessor):
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
return (128,)
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
self.check_shape(observation)
return (observation.astype("float32") - 128) / 128
@DeveloperAPI
class OneHotPreprocessor(Preprocessor):
"""One-hot preprocessor for Discrete and MultiDiscrete spaces.
Examples:
>>> self.transform(Discrete(3).sample())
... np.array([0.0, 1.0, 0.0])
>>> self.transform(MultiDiscrete([2, 3]).sample())
... np.array([0.0, 1.0, 0.0, 0.0, 1.0])
"""
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
if isinstance(obs_space, gym.spaces.Discrete):
return (self._obs_space.n,)
else:
return (np.sum(self._obs_space.nvec),)
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
self.check_shape(observation)
arr = np.zeros(self._init_shape(self._obs_space, {}), dtype=np.float32)
if isinstance(self._obs_space, gym.spaces.Discrete):
arr[observation] = 1
else:
for i, o in enumerate(observation):
arr[np.sum(self._obs_space.nvec[:i]) + o] = 1
return arr
@override(Preprocessor)
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
array[offset : offset + self.size] = self.transform(observation)
@PublicAPI
class NoPreprocessor(Preprocessor):
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
return self._obs_space.shape
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
self.check_shape(observation)
return observation
@override(Preprocessor)
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
array[offset : offset + self._size] = np.array(observation, copy=False).ravel()
@property
@override(Preprocessor)
def observation_space(self) -> gym.Space:
return self._obs_space
@DeveloperAPI
class TupleFlatteningPreprocessor(Preprocessor):
"""Preprocesses each tuple element, then flattens it all into a vector.
RLlib models will unpack the flattened output before _build_layers_v2().
"""
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
assert isinstance(self._obs_space, gym.spaces.Tuple)
size = 0
self.preprocessors = []
for i in range(len(self._obs_space.spaces)):
space = self._obs_space.spaces[i]
logger.debug("Creating sub-preprocessor for {}".format(space))
preprocessor_class = get_preprocessor(space)
if preprocessor_class is not None:
preprocessor = preprocessor_class(space, self._options)
size += preprocessor.size
else:
preprocessor = None
size += int(np.product(space.shape))
self.preprocessors.append(preprocessor)
return (size,)
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
self.check_shape(observation)
array = np.zeros(self.shape, dtype=np.float32)
self.write(observation, array, 0)
return array
@override(Preprocessor)
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
assert len(observation) == len(self.preprocessors), observation
for o, p in zip(observation, self.preprocessors):
p.write(o, array, offset)
offset += p.size
@DeveloperAPI
class DictFlatteningPreprocessor(Preprocessor):
"""Preprocesses each dict value, then flattens it all into a vector.
RLlib models will unpack the flattened output before _build_layers_v2().
"""
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
assert isinstance(self._obs_space, gym.spaces.Dict)
size = 0
self.preprocessors = []
for space in self._obs_space.spaces.values():
logger.debug("Creating sub-preprocessor for {}".format(space))
preprocessor_class = get_preprocessor(space)
if preprocessor_class is not None:
preprocessor = preprocessor_class(space, self._options)
size += preprocessor.size
else:
preprocessor = None
size += int(np.product(space.shape))
self.preprocessors.append(preprocessor)
return (size,)
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
self.check_shape(observation)
array = np.zeros(self.shape, dtype=np.float32)
self.write(observation, array, 0)
return array
@override(Preprocessor)
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
if not isinstance(observation, OrderedDict):
observation = OrderedDict(sorted(observation.items()))
assert len(observation) == len(self.preprocessors), (
len(observation),
len(self.preprocessors),
)
for o, p in zip(observation.values(), self.preprocessors):
p.write(o, array, offset)
offset += p.size
@DeveloperAPI
class RepeatedValuesPreprocessor(Preprocessor):
"""Pads and batches the variable-length list value."""
@override(Preprocessor)
def _init_shape(self, obs_space: gym.Space, options: dict) -> List[int]:
assert isinstance(self._obs_space, Repeated)
child_space = obs_space.child_space
self.child_preprocessor = get_preprocessor(child_space)(
child_space, self._options
)
# The first slot encodes the list length.
size = 1 + self.child_preprocessor.size * obs_space.max_len
return (size,)
@override(Preprocessor)
def transform(self, observation: TensorType) -> np.ndarray:
array = np.zeros(self.shape)
if isinstance(observation, list):
for elem in observation:
self.child_preprocessor.check_shape(elem)
else:
pass # ValueError will be raised in write() below.
self.write(observation, array, 0)
return array
@override(Preprocessor)
def write(self, observation: TensorType, array: np.ndarray, offset: int) -> None:
if not isinstance(observation, (list, np.ndarray)):
raise ValueError(
"Input for {} must be list type, got {}".format(self, observation)
)
elif len(observation) > self._obs_space.max_len:
raise ValueError(
"Input {} exceeds max len of space {}".format(
observation, self._obs_space.max_len
)
)
# The first slot encodes the list length.
array[offset] = len(observation)
for i, elem in enumerate(observation):
offset_i = offset + 1 + i * self.child_preprocessor.size
self.child_preprocessor.write(elem, array, offset_i)
@PublicAPI
def get_preprocessor(space: gym.Space) -> type:
"""Returns an appropriate preprocessor class for the given space."""
_legacy_patch_shapes(space)
obs_shape = space.shape
if isinstance(space, (gym.spaces.Discrete, gym.spaces.MultiDiscrete)):
preprocessor = OneHotPreprocessor
elif obs_shape == ATARI_OBS_SHAPE:
preprocessor = GenericPixelPreprocessor
elif obs_shape == ATARI_RAM_OBS_SHAPE:
preprocessor = AtariRamPreprocessor
elif isinstance(space, gym.spaces.Tuple):
preprocessor = TupleFlatteningPreprocessor
elif isinstance(space, gym.spaces.Dict):
preprocessor = DictFlatteningPreprocessor
elif isinstance(space, Repeated):
preprocessor = RepeatedValuesPreprocessor
else:
preprocessor = NoPreprocessor
return preprocessor
def _legacy_patch_shapes(space: gym.Space) -> List[int]:
"""Assigns shapes to spaces that don't have shapes.
This is only needed for older gym versions that don't set shapes properly
for Tuple and Discrete spaces.
"""
if not hasattr(space, "shape"):
if isinstance(space, gym.spaces.Discrete):
space.shape = ()
elif isinstance(space, gym.spaces.Tuple):
shapes = []
for s in space.spaces:
shape = _legacy_patch_shapes(s)
shapes.append(shape)
space.shape = tuple(shapes)
return space.shape