76 lines
2.6 KiB
Python
Executable File
76 lines
2.6 KiB
Python
Executable File
#!/usr/bin/env python
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"""Example of using PBT with RLlib.
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Note that this requires a cluster with at least 8 GPUs in order for all trials
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to run concurrently, otherwise PBT will round-robin train the trials which
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is less efficient (or you can set {"gpu": 0} to use CPUs for SGD instead).
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Note that Tune in general does not need 8 GPUs, and this is just a more
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computationally demanding example.
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"""
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import random
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from ray import tune
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from ray.rllib.algorithms.ppo import PPO
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from ray.tune.schedulers import PopulationBasedTraining
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if __name__ == "__main__":
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# Postprocess the perturbed config to ensure it's still valid
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def explore(config):
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# ensure we collect enough timesteps to do sgd
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if config["train_batch_size"] < config["sgd_minibatch_size"] * 2:
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config["train_batch_size"] = config["sgd_minibatch_size"] * 2
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# ensure we run at least one sgd iter
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if config["num_sgd_iter"] < 1:
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config["num_sgd_iter"] = 1
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return config
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pbt = PopulationBasedTraining(
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time_attr="time_total_s",
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perturbation_interval=120,
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resample_probability=0.25,
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# Specifies the mutations of these hyperparams
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hyperparam_mutations={
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"lambda": lambda: random.uniform(0.9, 1.0),
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"clip_param": lambda: random.uniform(0.01, 0.5),
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"lr": [1e-3, 5e-4, 1e-4, 5e-5, 1e-5],
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"num_sgd_iter": lambda: random.randint(1, 30),
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"sgd_minibatch_size": lambda: random.randint(128, 16384),
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"train_batch_size": lambda: random.randint(2000, 160000),
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},
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custom_explore_fn=explore,
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)
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tuner = tune.Tuner(
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PPO,
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run_config=tune.RunConfig(
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name="pbt_humanoid_test",
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),
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tune_config=tune.TuneConfig(
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scheduler=pbt,
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num_samples=8,
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metric="episode_reward_mean",
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mode="max",
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reuse_actors=True,
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),
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param_space={
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"env": "Humanoid-v1",
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"kl_coeff": 1.0,
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"num_workers": 8,
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"num_gpus": 1,
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"model": {"free_log_std": True},
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# These params are tuned from a fixed starting value.
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"lambda": 0.95,
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"clip_param": 0.2,
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"lr": 1e-4,
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# These params start off randomly drawn from a set.
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"num_sgd_iter": tune.choice([10, 20, 30]),
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"sgd_minibatch_size": tune.choice([128, 512, 2048]),
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"train_batch_size": tune.choice([10000, 20000, 40000]),
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},
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)
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results = tuner.fit()
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print("best hyperparameters: ", results.get_best_result().config)
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