ray/examples/hyperopt/hyperopt_simple.py
Abishek Bhat 6da7761d5d Fix overlooked typo. (#1158)
Without this the example script would crash with an UnboundLocalError.
2017-10-25 07:40:52 -07:00

100 lines
4.1 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import numpy as np
import ray
import argparse
from tensorflow.examples.tutorials.mnist import input_data
import objective
parser = argparse.ArgumentParser(description="Run the hyperparameter "
"optimization example.")
parser.add_argument("--trials", default=2, type=int,
help="The number of random trials to do.")
parser.add_argument("--steps", default=10, type=int,
help="The number of steps of training to do per network.")
parser.add_argument("--redis-address", default=None, type=str,
help="The Redis address of the cluster.")
if __name__ == "__main__":
args = parser.parse_args()
ray.init(redis_address=args.redis_address)
# The number of sets of random hyperparameters to try.
trials = args.trials
# The number of training passes over the dataset to use for network.
steps = args.steps
# Load the mnist data and turn the data into remote objects.
print("Downloading the MNIST dataset. This may take a minute.")
mnist = input_data.read_data_sets("MNIST_data", one_hot=True)
train_images = ray.put(mnist.train.images)
train_labels = ray.put(mnist.train.labels)
validation_images = ray.put(mnist.validation.images)
validation_labels = ray.put(mnist.validation.labels)
# Keep track of the best hyperparameters and the best accuracy.
best_hyperparameters = None
best_accuracy = 0
# This list holds the object IDs for all of the experiments that we have
# launched and that have not yet been processed.
remaining_ids = []
# This is a dictionary mapping the object ID of an experiment to the
# hyerparameters used for that experiment.
hyperparameters_mapping = {}
# A function for generating random hyperparameters.
def generate_hyperparameters():
return {"learning_rate": 10 ** np.random.uniform(-5, 5),
"batch_size": np.random.randint(1, 100),
"dropout": np.random.uniform(0, 1),
"stddev": 10 ** np.random.uniform(-5, 5)}
# Randomly generate some hyperparameters, and launch a task for each set.
for i in range(trials):
hyperparameters = generate_hyperparameters()
accuracy_id = objective.train_cnn_and_compute_accuracy.remote(
hyperparameters, steps, train_images, train_labels,
validation_images, validation_labels)
remaining_ids.append(accuracy_id)
# Keep track of which hyperparameters correspond to this experiment.
hyperparameters_mapping[accuracy_id] = hyperparameters
# Fetch and print the results of the tasks in the order that they complete.
for i in range(trials):
# Use ray.wait to get the object ID of the first task that completes.
ready_ids, remaining_ids = ray.wait(remaining_ids)
# Process the output of this task.
result_id = ready_ids[0]
hyperparameters = hyperparameters_mapping[result_id]
accuracy, _ = ray.get(result_id)
print("""We achieve accuracy {:.3}% with
learning_rate: {:.2}
batch_size: {}
dropout: {:.2}
stddev: {:.2}
""".format(100 * accuracy,
hyperparameters["learning_rate"],
hyperparameters["batch_size"],
hyperparameters["dropout"],
hyperparameters["stddev"]))
if accuracy > best_accuracy:
best_hyperparameters = hyperparameters
best_accuracy = accuracy
# Record the best performing set of hyperparameters.
print("""Best accuracy over {} trials was {:.3} with
learning_rate: {:.2}
batch_size: {}
dropout: {:.2}
stddev: {:.2}
""".format(trials, 100 * best_accuracy,
best_hyperparameters["learning_rate"],
best_hyperparameters["batch_size"],
best_hyperparameters["dropout"],
best_hyperparameters["stddev"]))