Amidar¶
This environment is part of the Atari environments. Please read that page first for general information.
Action Space |
Discrete(10) |
Observation Space |
Box(0, 255, (210, 160, 3), uint8) |
Import |
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For more Amidar variants with different observation and action spaces, see the variants section.
Description¶
This game is similar to Pac-Man: You are trying to visit all places on a 2-dimensional grid while simultaneously avoiding your enemies. You can turn the tables at one point in the game: Your enemies turn into chickens and you can catch them.
For a more detailed documentation, see the AtariAge page
Actions¶
Amidar has the action space of Discrete(10)
with the table below listing the meaning of each action’s meanings.
To enable all 18 possible actions that can be performed on an Atari 2600, specify full_action_space=True
during
initialization or by passing full_action_space=True
to gymnasium.make
.
Value |
Meaning |
Value |
Meaning |
Value |
Meaning |
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See environment specification to see more information on the action meaning.
Observations¶
Atari environments have three possible observation types: "rgb"
, "grayscale"
and "ram"
.
obs_type="rgb" -> observation_space=Box(0, 255, (210, 160, 3), np.uint8)
obs_type="ram" -> observation_space=Box(0, 255, (128,), np.uint8)
obs_type="grayscale" -> Box(0, 255, (210, 160), np.uint8)
, a grayscale version of the “rgb” type
See variants section for the type of observation used by each environment id by default.
Rewards¶
You score points by traversing new parts of the grid. Coloring an entire box in the maze or catching chickens gives extra points. For a more detailed documentation, see the AtariAge page.
Variants¶
Amidar has the following variants of the environment id which have the following differences in observation, the number of frame-skips and the repeat action probability.
Env-id |
obs_type= |
frameskip= |
repeat_action_probability= |
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Amidar-v0 |
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Amidar-ram-v0 |
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Amidar-ramDeterministic-v0 |
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Amidar-ramNoFrameskip-v0 |
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AmidarDeterministic-v0 |
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AmidarNoFrameskip-v0 |
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Amidar-v4 |
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Amidar-ram-v4 |
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Amidar-ramDeterministic-v4 |
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Amidar-ramNoFrameskip-v4 |
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AmidarDeterministic-v4 |
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AmidarNoFrameskip-v4 |
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ALE/Amidar-v5 |
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ALE/Amidar-ram-v5 |
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Difficulty and modes¶
It is possible to specify various flavors of the environment via the keyword arguments difficulty
and mode
.
A flavor is a combination of a game mode and a difficulty setting. The table below lists the possible difficulty and mode values
along with the default values.
Available Modes |
Default Mode |
Available Difficulties |
Default Difficulty |
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Version History¶
A thorough discussion of the intricate differences between the versions and configurations can be found in the general article on Atari environments.
v5: Stickiness was added back and stochastic frame-skipping was removed. The environments are now in the “ALE” namespace.
v4: Stickiness of actions was removed
v0: Initial versions release