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ray/python/ray/tune/examples/bohb_example.py
T
Richard Liaw 9f3e9e7e9f [tune] Add more intensive tests (#7667)
* make_heavier_tests

* help
2020-04-20 11:14:44 -07:00

70 lines
2.0 KiB
Python

#!/usr/bin/env python
import json
import os
import numpy as np
import ray
from ray.tune import Trainable, run
from ray.tune.schedulers.hb_bohb import HyperBandForBOHB
from ray.tune.suggest.bohb import TuneBOHB
class MyTrainableClass(Trainable):
"""Example agent whose learning curve is a random sigmoid.
The dummy hyperparameters "width" and "height" determine the slope and
maximum reward value reached.
"""
def _setup(self, config):
self.timestep = 0
def _train(self):
self.timestep += 1
v = np.tanh(float(self.timestep) / self.config.get("width", 1))
v *= self.config.get("height", 1)
# Here we use `episode_reward_mean`, but you can also report other
# objectives such as loss or accuracy.
return {"episode_reward_mean": v}
def _save(self, checkpoint_dir):
path = os.path.join(checkpoint_dir, "checkpoint")
with open(path, "w") as f:
f.write(json.dumps({"timestep": self.timestep}))
return path
def _restore(self, checkpoint_path):
with open(checkpoint_path) as f:
self.timestep = json.loads(f.read())["timestep"]
if __name__ == "__main__":
import ConfigSpace as CS
ray.init(num_cpus=8)
# BOHB uses ConfigSpace for their hyperparameter search space
config_space = CS.ConfigurationSpace()
config_space.add_hyperparameter(
CS.UniformFloatHyperparameter("height", lower=10, upper=100))
config_space.add_hyperparameter(
CS.UniformFloatHyperparameter("width", lower=0, upper=100))
experiment_metrics = dict(metric="episode_reward_mean", mode="max")
bohb_hyperband = HyperBandForBOHB(
time_attr="training_iteration",
max_t=100,
reduction_factor=4,
**experiment_metrics)
bohb_search = TuneBOHB(
config_space, max_concurrent=4, **experiment_metrics)
run(MyTrainableClass,
name="bohb_test",
scheduler=bohb_hyperband,
search_alg=bohb_search,
num_samples=10,
stop={"training_iteration": 100})