ray/examples/hyperopt/objective.py
Robert Nishihara 3ebfd850e1 Make example applications pep8 compliant. (#553)
* Test examples for pep8 compliance.

* Make rl_pong example pep8 compliant.

* Make policy gradient example pep8 compliant.

* Make lbfgs example pep8 compliant.

* Make hyperopt example pep8 compliant.

* Make a3c example pep8 compliant.

* Make evolution strategies example pep8 compliant.

* Make resnet example pep8 compliant.

* Fix.
2017-05-16 14:12:18 -07:00

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Python

# Most of the tensorflow code is adapted from Tensorflow's tutorial on using
# CNNs to train MNIST
# https://www.tensorflow.org/versions/r0.9/tutorials/mnist/pros/index.html#build-a-multilayer-convolutional-network. # noqa: E501
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import ray
import tensorflow as tf
def get_batch(data, batch_index, batch_size):
# This method currently drops data when num_data is not divisible by
# batch_size.
num_data = data.shape[0]
num_batches = num_data // batch_size
batch_index %= num_batches
return data[(batch_index * batch_size):((batch_index + 1) * batch_size)]
def weight(shape, stddev):
initial = tf.truncated_normal(shape, stddev=stddev)
return tf.Variable(initial)
def bias(shape):
initial = tf.constant(0.1, shape=shape)
return tf.Variable(initial)
def conv2d(x, W):
return tf.nn.conv2d(x, W, strides=[1, 1, 1, 1], padding="SAME")
def max_pool_2x2(x):
return tf.nn.max_pool(x, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1],
padding="SAME")
def cnn_setup(x, y, keep_prob, lr, stddev):
first_hidden = 32
second_hidden = 64
fc_hidden = 1024
W_conv1 = weight([5, 5, 1, first_hidden], stddev)
B_conv1 = bias([first_hidden])
x_image = tf.reshape(x, [-1, 28, 28, 1])
h_conv1 = tf.nn.relu(conv2d(x_image, W_conv1) + B_conv1)
h_pool1 = max_pool_2x2(h_conv1)
W_conv2 = weight([5, 5, first_hidden, second_hidden], stddev)
b_conv2 = bias([second_hidden])
h_conv2 = tf.nn.relu(conv2d(h_pool1, W_conv2) + b_conv2)
h_pool2 = max_pool_2x2(h_conv2)
W_fc1 = weight([7 * 7 * second_hidden, fc_hidden], stddev)
b_fc1 = bias([fc_hidden])
h_pool2_flat = tf.reshape(h_pool2, [-1, 7 * 7 * second_hidden])
h_fc1 = tf.nn.relu(tf.matmul(h_pool2_flat, W_fc1) + b_fc1)
h_fc1_drop = tf.nn.dropout(h_fc1, keep_prob)
W_fc2 = weight([fc_hidden, 10], stddev)
b_fc2 = bias([10])
y_conv = tf.nn.softmax(tf.matmul(h_fc1_drop, W_fc2) + b_fc2)
cross_entropy = tf.reduce_mean(-tf.reduce_sum(y * tf.log(y_conv),
reduction_indices=[1]))
correct_pred = tf.equal(tf.argmax(y_conv, 1), tf.argmax(y, 1))
return (tf.train.AdamOptimizer(lr).minimize(cross_entropy),
tf.reduce_mean(tf.cast(correct_pred, tf.float32)), cross_entropy)
# Define a remote function that takes a set of hyperparameters as well as the
# data, consructs and trains a network, and returns the validation accuracy.
@ray.remote
def train_cnn_and_compute_accuracy(params, steps, train_images, train_labels,
validation_images, validation_labels,
weights=None):
# Extract the hyperparameters from the params dictionary.
learning_rate = params["learning_rate"]
batch_size = params["batch_size"]
keep = 1 - params["dropout"]
stddev = params["stddev"]
# Create the network and related variables.
with tf.Graph().as_default():
# Create the input placeholders for the network.
x = tf.placeholder(tf.float32, shape=[None, 784])
y = tf.placeholder(tf.float32, shape=[None, 10])
keep_prob = tf.placeholder(tf.float32)
# Create the network.
train_step, accuracy, loss = cnn_setup(x, y, keep_prob, learning_rate,
stddev)
# Do the training and evaluation.
with tf.Session() as sess:
# Use the TensorFlowVariables utility. This is only necessary if we want
# to set and get the weights.
variables = ray.experimental.TensorFlowVariables(loss, sess)
# Initialize the network weights.
sess.run(tf.global_variables_initializer())
# If some network weights were passed in, set those.
if weights is not None:
variables.set_weights(weights)
# Do some steps of training.
for i in range(1, steps + 1):
# Fetch the next batch of data.
image_batch = get_batch(train_images, i, batch_size)
label_batch = get_batch(train_labels, i, batch_size)
# Do one step of training.
sess.run(train_step, feed_dict={x: image_batch, y: label_batch,
keep_prob: keep})
# Training is done, so compute the validation accuracy and the current
# weights and return.
totalacc = accuracy.eval(feed_dict={x: validation_images,
y: validation_labels,
keep_prob: 1.0})
new_weights = variables.get_weights()
return float(totalacc), new_weights