ray/rllib/examples/custom_torch_policy.py
Matthew A. Wright e3c9f7e83a Custom action distributions (#5164)
* custom action dist wip

* Test case for custom action dist

* ActionDistribution.get_parameter_shape_for_action_space pattern

* Edit exception message to also suggest using a custom action distribution

* Clean up ModelCatalog.get_action_dist

* Pass model config to ActionDistribution constructors

* Update custom action distribution test case

* Name fix

* Autoformatter

* parameter shape static methods for torch distributions

* Fix docstring

* Generalize fake array for graph initialization

* Fix action dist constructors

* Correct parameter shape static methods for multicategorical and gaussian

* Make suggested changes to custom action dist's

* Correct instances of not passing model config to action dist

* Autoformatter

* fix tuple distribution constructor

* bugfix
2019-08-06 11:13:16 -07:00

45 lines
1.3 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import argparse
import ray
from ray import tune
from ray.rllib.agents.trainer_template import build_trainer
from ray.rllib.policy.sample_batch import SampleBatch
from ray.rllib.policy.torch_policy_template import build_torch_policy
parser = argparse.ArgumentParser()
parser.add_argument("--iters", type=int, default=200)
def policy_gradient_loss(policy, batch_tensors):
logits, _ = policy.model({
SampleBatch.CUR_OBS: batch_tensors[SampleBatch.CUR_OBS]
})
action_dist = policy.dist_class(logits, policy.config["model"])
log_probs = action_dist.logp(batch_tensors[SampleBatch.ACTIONS])
return -batch_tensors[SampleBatch.REWARDS].dot(log_probs)
# <class 'ray.rllib.policy.torch_policy_template.MyTorchPolicy'>
MyTorchPolicy = build_torch_policy(
name="MyTorchPolicy", loss_fn=policy_gradient_loss)
# <class 'ray.rllib.agents.trainer_template.MyCustomTrainer'>
MyTrainer = build_trainer(
name="MyCustomTrainer",
default_policy=MyTorchPolicy,
)
if __name__ == "__main__":
ray.init()
args = parser.parse_args()
tune.run(
MyTrainer,
stop={"training_iteration": args.iters},
config={
"env": "CartPole-v0",
"num_workers": 2,
})