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from agent.hyperparameters import QNetworkHyperparameters
import numpy as np
import tensorflow as tf
import math
import logging
from collections import namedtuple
TFGraphForwardPassBundle = namedtuple('TFGraphForwardPropBundle',
['input_state',
'output_all_actions_q_values',
'variable_scope_name_prefix'])
TFGraphTrainBundle = namedtuple('TFGraphTrainBundle',
['input_states',
'output_all_actions_q_values',
'action_indexes',
'target_action_q_values',
'learning_rate',
'loss',
'optimizer',
'variable_scope_name_prefix'])
QNetworkTrainBundle = namedtuple("QNetworkTrainBundle", ["state", "action_index", "target_action_q_value"])
class QNetworkFactory(object):
def create(self, screen_width, screen_height, num_channels, num_actions, metrics_directory, batched_forward_pass_size):
return QNetwork(screen_width, screen_height, num_channels, num_actions, metrics_directory, batched_forward_pass_size)
class QNetwork(object):
MODEL_NAME_TRAIN = 'model-train'
MODEL_NAME_FORWARD_PASS = 'model-forward-pass'
def __init__(self,
screen_width,
screen_height,
num_channels,
num_actions,
metrics_directory,
batched_forward_pass_size,
hyperparameters=QNetworkHyperparameters()):
self.logger = logging.getLogger(__name__)
self.screen_width = screen_width
self.screen_height = screen_height
self.num_channels = num_channels
self.num_actions = num_actions
self.batched_forward_pass_size = batched_forward_pass_size
self.hyperparameters = hyperparameters
self.tf_graph = tf.Graph()
self.tf_graph_forward_pass_bundle_single = self._build_graph_forward_pass_bundle(self.tf_graph, 1)
self.tf_graph_forward_pass_bundle_batched = self._build_graph_forward_pass_bundle(self.tf_graph, batched_forward_pass_size)
self.tf_graph_train_bundle = self._build_graph_train_bundle(self.tf_graph)
self.tf_session = tf.Session(graph=self.tf_graph)
with self.tf_graph.as_default():
self.tf_all_summaries = tf.merge_all_summaries()
self.tf_summary_writer = tf.train.SummaryWriter(logdir=metrics_directory, graph=self.tf_graph)
self.tf_saver = tf.train.Saver()
tf.initialize_all_variables().run(session=self.tf_session)
self.assigns_train_to_forward_pass_variables = self._build_assigns_train_to_forward_pass_variables()
def _build_graph_forward_pass_bundle(self, graph, batch_size):
with graph.as_default():
input_state = tf.placeholder(tf.float32,
shape=(batch_size, self.screen_height, self.screen_width, self.num_channels),
name='input_state')
variable_scope_name_prefix = "{0}-{1}-scope".format(self.MODEL_NAME_FORWARD_PASS, batch_size)
output_all_actions_q_values = self._network_model(variable_scope_name_prefix=variable_scope_name_prefix,
input=input_state,
output_size=self.num_actions,
record_metrics=False)
return TFGraphForwardPassBundle(input_state=input_state,
output_all_actions_q_values=output_all_actions_q_values,
variable_scope_name_prefix=variable_scope_name_prefix)
def _build_graph_train_bundle(self, graph):
with graph.as_default():
input_states = tf.placeholder(tf.float32,
shape=(self.hyperparameters.SGD_BATCH_SIZE, self.screen_height, self.screen_width, self.num_channels),
name='input_states')
variable_scope_name_prefix=self.MODEL_NAME_TRAIN
output_all_actions_q_values = self._network_model(variable_scope_name_prefix=variable_scope_name_prefix,
input=input_states,
output_size=self.num_actions,
record_metrics=True)
action_indexes = tf.placeholder(tf.float32, shape=(self.hyperparameters.SGD_BATCH_SIZE, self.num_actions), name='action_indexes')
output_filtered_action_q_values = tf.reduce_sum(tf.mul(output_all_actions_q_values, action_indexes), reduction_indices=1)
target_action_q_values = tf.placeholder(tf.float32, shape=(self.hyperparameters.SGD_BATCH_SIZE), name='target_action_q_values')
delta = target_action_q_values - output_filtered_action_q_values
loss = tf.reduce_mean(tf.square(delta))
learning_rate = tf.Variable(self.hyperparameters.LEARNING_RATE_INITIAL, trainable=False)
optimizer = tf.train.RMSPropOptimizer(learning_rate,
decay=self.hyperparameters.RMS_DECAY,
momentum=self.hyperparameters.RMS_MOMENTUM,
epsilon=self.hyperparameters.RMS_EPSILON).minimize(loss)
tf.scalar_summary('loss', loss)
tf.scalar_summary('learning_rate', learning_rate)
return TFGraphTrainBundle(input_states=input_states,
output_all_actions_q_values=output_all_actions_q_values,
action_indexes=action_indexes,
target_action_q_values=target_action_q_values,
learning_rate=learning_rate,
loss=loss,
optimizer=optimizer,
variable_scope_name_prefix=variable_scope_name_prefix)
def _network_model(self, variable_scope_name_prefix, input, output_size, record_metrics):
conv1 = self._convolutional_layer(input=input,
patch_size=8,
stride=4,
input_channels=self.num_channels,
output_channels=32,
bias_init_value=0.0,
scope_name=variable_scope_name_prefix + '_conv1')
conv2 = self._convolutional_layer(input=conv1,
patch_size=4,
stride=2,
input_channels=32,
output_channels=64,
bias_init_value=0.1,
scope_name=variable_scope_name_prefix + '_conv2')
conv3 = self._convolutional_layer(input=conv2,
patch_size=3,
stride=1,
input_channels=64,
output_channels=64,
bias_init_value=0.1,
scope_name=variable_scope_name_prefix + '_conv3')
flattened_conv3 = tf.reshape(conv3, [input.get_shape()[0].value, -1])
flattened_conv3_size = flattened_conv3.get_shape()[1].value
# relu4
relu4 = self._relu_layer(input=flattened_conv3,
input_size=flattened_conv3_size,
output_size=512,
scope_name=variable_scope_name_prefix + '_relu4')
local5 = self._linear_layer(input=relu4,
input_size=512,
output_size=output_size,
scope_name=variable_scope_name_prefix + '_local5')
if record_metrics:
self._activation_summary(conv1)
self._activation_summary(conv2)
self._activation_summary(conv3)
self._activation_summary(relu4)
self._activation_summary(local5)
return local5
def _convolutional_layer(self, input, patch_size, stride, input_channels, output_channels, bias_init_value, scope_name):
with tf.variable_scope(scope_name) as scope:
weights = tf.get_variable(name='weights',
shape=[patch_size, patch_size, input_channels, output_channels],
initializer=tf.contrib.layers.xavier_initializer_conv2d())
biases = tf.Variable(name='biases', initial_value=tf.constant(value=bias_init_value, shape=[output_channels]))
conv = tf.nn.conv2d(input, weights, [1, stride, stride, 1], padding='SAME')
linear_rectification_bias = tf.nn.bias_add(conv, biases)
output = tf.nn.relu(linear_rectification_bias, name=scope.name)
grid_x = output_channels // 4
grid_y = 4 * input_channels
kernels_image_grid = self._create_kernels_image_grid(weights, (grid_x, grid_y))
tf.image_summary(scope_name + '/features', kernels_image_grid, max_images=1)
if "_conv1" in scope_name:
x_min = tf.reduce_min(weights)
x_max = tf.reduce_max(weights)
weights_0_to_1 = (weights - x_min) / (x_max - x_min)
weights_0_to_255_uint8 = tf.image.convert_image_dtype(weights_0_to_1, dtype=tf.uint8)
# to tf.image_summary format [batch_size, height, width, channels]
weights_transposed = tf.transpose(weights_0_to_255_uint8, [3, 0, 1, 2])
tf.image_summary(scope_name + '/features', weights_transposed[:,:,:,0:1], max_images=32)
return output
def _relu_layer(self, input, input_size, output_size, scope_name):
with tf.variable_scope(scope_name) as scope:
weights = tf.get_variable(name='weights',
shape=[input_size, output_size],
initializer=tf.contrib.layers.xavier_initializer())
biases = tf.Variable(name='biases', initial_value=tf.constant(value=0.1, shape=[output_size]))
output = tf.nn.relu(tf.matmul(input, weights) + biases, name=scope.name)
return output
def _linear_layer(self, input, input_size, output_size, scope_name):
with tf.variable_scope(scope_name) as scope:
weights = tf.Variable(name='weights',
initial_value=tf.truncated_normal(shape=[input_size, output_size], stddev=0.1))
biases = tf.Variable(name='biases', initial_value=tf.constant(value=0.1, shape=[output_size]))
output = tf.matmul(input, weights) + biases
return output
def _activation_summary(self, tensor):
tensor_name = tensor.op.name
tf.histogram_summary(tensor_name + '/activations', tensor)
tf.scalar_summary(tensor_name + '/sparsity', tf.nn.zero_fraction(tensor))
def _create_kernels_image_grid(self, kernel, (grid_X, grid_Y), pad=1):
'''Visualize conv. features as an image (mostly for the 1st layer).
Place kernel into a grid, with some paddings between adjacent filters.
Args:
kernel: tensor of shape [Y, X, NumChannels, NumKernels]
(grid_X, grid_Y): shape of the grid. Require: NumKernels == grid_X * grid_Y
User is responsible of how to break into two multiples.
pad: number of black pixels around each filter (between them)
Return:
Tensor of shape [(Y+pad)*grid_Y, (X+pad)*grid_X, NumChannels, 1].
'''
flattened_kernel = tf.reshape(kernel, tf.pack([kernel.get_shape()[0],
kernel.get_shape()[1],
1,
kernel.get_shape()[3] * kernel.get_shape()[2]]))
# X and Y dimensions, w.r.t. padding
Y = flattened_kernel.get_shape()[0] + pad
X = flattened_kernel.get_shape()[1] + pad
# pad X and Y
x1 = tf.pad(flattened_kernel, tf.constant([[pad, 0], [pad, 0], [0, 0], [0, 0]]))
# put NumKernels to the 1st dimension
x2 = tf.transpose(x1, (3, 0, 1, 2))
# organize grid on Y axis
x3 = tf.reshape(x2, tf.pack([grid_X, Y * grid_Y, X, 1]))
# switch X and Y axes
x4 = tf.transpose(x3, (0, 2, 1, 3))
# organize grid on X axis
x5 = tf.reshape(x4, tf.pack([1, X * grid_X, Y * grid_Y, 1]))
# back to normal order (not combining with the next step for clarity)
x6 = tf.transpose(x5, (2, 1, 3, 0))
# to tf.image_summary order [batch_size, height, width, channels],
# where in this case batch_size == 1
x7 = tf.transpose(x6, (3, 0, 1, 2))
# scale to [0, 1]
x_min = tf.reduce_min(x7)
x_max = tf.reduce_max(x7)
x8 = (x7 - x_min) / (x_max - x_min)
return x8
def create_train_bundle(self, state, action_index, target_action_q_value):
return QNetworkTrainBundle(state=state,
action_index=action_index,
target_action_q_value=target_action_q_value)
def train(self, train_bundles, training_step):
train_bundles_len = len(train_bundles)
if train_bundles_len < self.hyperparameters.SGD_BATCH_SIZE:
self.logger.info('Training bundle is smaller than batch size, skipping train')
return
offset = self.hyperparameters.SGD_BATCH_SIZE % train_bundles_len
batch_train_bundles = self._circular_selection_of_batch(offset, train_bundles, train_bundles_len)
batch_input_states = [train_bundle.state for train_bundle in batch_train_bundles]
batch_action_indexes = [np.eye(self.num_actions)[train_bundle.action_index] for train_bundle in
batch_train_bundles]
batch_target_action_q_values = [train_bundle.target_action_q_value for train_bundle in batch_train_bundles]
feed_dict = {
self.tf_graph_train_bundle.input_states: np.asarray(batch_input_states),
self.tf_graph_train_bundle.action_indexes: np.asarray(batch_action_indexes),
self.tf_graph_train_bundle.target_action_q_values: np.asarray(batch_target_action_q_values)
}
with self.tf_session.as_default():
run_result = self.tf_session.run(
[self.tf_graph_train_bundle.loss,
self.tf_graph_train_bundle.optimizer],
feed_dict=feed_dict)
evaluated_loss = run_result[0]
self.logger.info('Loss: %f' % evaluated_loss)
if training_step % self.hyperparameters.NUM_STEPS_ASSIGN_TRAIN_TO_FORWARD_PROP_GRAPH == 0:
self.tf_session.run(self.assigns_train_to_forward_pass_variables)
self.logger.info("Assigning trained variables to forward pass graph")
if (training_step + 1) % self.hyperparameters.LEARNING_RATE_DECAY_STEP == 0:
current_learning_rate = self.tf_session.run([self.tf_graph_train_bundle.learning_rate])[0]
learning_rate_decay = math.pow(float(self.hyperparameters.LEARNING_RATE_FINAL) / float(self.hyperparameters.LEARNING_RATE_INITIAL),
1.0 / (float(self.hyperparameters.LEARNING_RATE_FINAL_AT_STEP) / float(self.hyperparameters.LEARNING_RATE_DECAY_STEP)))
next_learning_rate = current_learning_rate * learning_rate_decay
self.tf_session.run(tf.assign(self.tf_graph_train_bundle.learning_rate, next_learning_rate))
if training_step % self.hyperparameters.METRICS_SAVE_STEP == 0:
evaluated_all_summaries = self.tf_session.run([self.tf_all_summaries], feed_dict=feed_dict)[0]
self.tf_summary_writer.add_summary(evaluated_all_summaries, training_step)
return evaluated_loss
def _circular_selection_of_batch(self, offset, train_bundles, train_bundles_len):
selection_end_of_list = train_bundles[offset:min(train_bundles_len, (offset + self.hyperparameters.SGD_BATCH_SIZE))]
selection_beggining_of_list = train_bundles[0:max(0, ((offset + self.hyperparameters.SGD_BATCH_SIZE) - train_bundles_len))]
return selection_end_of_list + selection_beggining_of_list
def forward_pass_single(self, input_state):
return self._forward_pass([input_state], self.tf_graph_forward_pass_bundle_single)
def forward_pass_batched(self, input_states):
return self._forward_pass(input_states, self.tf_graph_forward_pass_bundle_batched)
def _forward_pass(self, input_states, forward_pass_graph_bundle):
feed_dict = {forward_pass_graph_bundle.input_state: np.asarray(self._replace_non_existing_states_with_zeroed_states(input_states))}
with self.tf_session.as_default():
return self.tf_session.run(
[forward_pass_graph_bundle.output_all_actions_q_values],
feed_dict=feed_dict)[0]
def _replace_non_existing_states_with_zeroed_states(self, states):
result = [None] * len(states)
for idx, state in enumerate(states):
if state is None:
result[idx] = np.zeros((self.screen_height, self.screen_width, self.num_channels))
else:
result[idx] = state
return result
def _build_assigns_train_to_forward_pass_variables(self):
assigns = []
with self.tf_graph.as_default():
for variable in tf.all_variables():
self._assign_forward_pass_variable_to_train_variable(forward_pass_prefix=self.tf_graph_forward_pass_bundle_single.variable_scope_name_prefix,
variable=variable,
assigns=assigns)
self._assign_forward_pass_variable_to_train_variable(forward_pass_prefix=self.tf_graph_forward_pass_bundle_batched.variable_scope_name_prefix,
variable=variable,
assigns=assigns)
return assigns
def _assign_forward_pass_variable_to_train_variable(self, forward_pass_prefix, variable, assigns):
if variable.name.startswith(forward_pass_prefix):
forward_pass_variable = variable
train_variable_name = forward_pass_variable.name.replace(forward_pass_prefix, self.tf_graph_train_bundle.variable_scope_name_prefix)
train_variable = [v for v in tf.all_variables() if train_variable_name in v.name][0]
assigns.append(forward_pass_variable.assign(train_variable))
self.logger.debug("{target} will be assigned to {source} when summoned".format(target=forward_pass_variable.name,
source=train_variable.name))
def save(self, path):
with self.tf_session.as_default():
save_path = self.tf_saver.save(self.tf_session, path)
self.logger.info("Q Network saved in file: %s" % save_path)
def restore(self, path):
with self.tf_session.as_default():
self.tf_saver.restore(self.tf_session, path)
self.logger.info("Q Network restored from file: %s" % path)