ray/rllib/examples/checkpoint_by_custom_criteria.py
xwjiang2010 fcf897ee72
[air] update rllib example to use Tuner API. (#26987)
update rllib example to use Tuner API.

Signed-off-by: xwjiang2010 <xwjiang2010@gmail.com>
2022-07-27 12:12:59 +01:00

91 lines
3.2 KiB
Python

import argparse
import os
import ray
from ray import air, tune
parser = argparse.ArgumentParser()
parser.add_argument(
"--run", type=str, default="PPO", help="The RLlib-registered algorithm to use."
)
parser.add_argument("--num-cpus", type=int, default=0)
parser.add_argument(
"--framework",
choices=["tf", "tf2", "tfe", "torch"],
default="tf",
help="The DL framework specifier.",
)
parser.add_argument("--stop-iters", type=int, default=200)
parser.add_argument("--stop-timesteps", type=int, default=100000)
parser.add_argument("--stop-reward", type=float, default=150.0)
if __name__ == "__main__":
args = parser.parse_args()
ray.init(num_cpus=args.num_cpus or None)
# Simple PPO config.
config = {
"env": "CartPole-v0",
# Run 3 trials.
"lr": tune.grid_search([0.01, 0.001, 0.0001]),
# Use GPUs iff `RLLIB_NUM_GPUS` env var set to > 0.
"num_gpus": int(os.environ.get("RLLIB_NUM_GPUS", "0")),
"framework": args.framework,
# Run with tracing enabled for tfe/tf2.
"eager_tracing": args.framework in ["tfe", "tf2"],
}
stop = {
"training_iteration": args.stop_iters,
"timesteps_total": args.stop_timesteps,
"episode_reward_mean": args.stop_reward,
}
# Run tune for some iterations and generate checkpoints.
tuner = tune.Tuner(
args.run,
param_space=config,
run_config=air.RunConfig(
stop=stop, checkpoint_config=air.CheckpointConfig(checkpoint_frequency=1)
),
)
results = tuner.fit()
# Get the best of the 3 trials by using some metric.
# NOTE: Choosing the min `episodes_this_iter` automatically picks the trial
# with the best performance (over the entire run (scope="all")):
# The fewer episodes, the longer each episode lasted, the more reward we
# got each episode.
# Setting scope to "last", "last-5-avg", or "last-10-avg" will only compare
# (using `mode=min|max`) the average values of the last 1, 5, or 10
# iterations with each other, respectively.
# Setting scope to "avg" will compare (using `mode`=min|max) the average
# values over the entire run.
metric = "episodes_this_iter"
# notice here `scope` is `all`, meaning for each trial,
# all results (not just the last one) will be examined.
best_result = results.get_best_result(metric=metric, mode="min", scope="all")
value_best_metric = best_result.metrics_dataframe[metric].min()
print(
"Best trial's lowest episode length (over all "
"iterations): {}".format(value_best_metric)
)
# Confirm, we picked the right trial.
assert value_best_metric <= results.get_dataframe()[metric].min()
# Get the best checkpoints from the trial, based on different metrics.
# Checkpoint with the lowest policy loss value:
ckpt = results.get_best_result(
metric="info/learner/default_policy/learner_stats/policy_loss", mode="min"
).checkpoint
print("Lowest pol-loss: {}".format(ckpt))
# Checkpoint with the highest value-function loss:
ckpt = results.get_best_result(
metric="info/learner/default_policy/learner_stats/vf_loss", mode="max"
).checkpoint
print("Highest vf-loss: {}".format(ckpt))
ray.shutdown()