Executando o modelo Keras para previsão em vários encadeamentos
igual aessa questão Eu estava executando um algoritmo de aprendizado por reforço assíncrono e preciso executar a previsão do modelo em vários threads para obter dados de treinamento mais rapidamente. Meu código é baseado emDDPG-keras no GitHub, cuja rede neural foi construída sobre o Keras & Tensorflow. Partes do meu código são mostradas abaixo:
Criação de thread assíncrona e junção:
for roundNo in xrange(self.param['max_round']):
AgentPool = [AgentThread(self.getEnv(), self.actor, self.critic, eps, self.param['n_step'], self.param['gamma'])]
for agent in AgentPool:
agent.start()
for agent in AgentPool:
agent.join()
Código do Encadeamento do Agente
"""Agent Thread for collecting data"""
def __init__(self, env_, actor_, critic_, eps_, n_step_, gamma_):
super(AgentThread, self).__init__()
self.env = env_ # type: Environment
self.actor = actor_ # type: ActorNetwork
# TODO: use Q(s,a)
self.critic = critic_ # type: CriticNetwork
self.eps = eps_ # type: float
self.n_step = n_step_ # type: int
self.gamma = gamma_
self.data = {}
def run(self):
"""run behavior policy self.actor to collect experience data in self.data"""
state = self.env.get_state()
action = self.actor.model.predict(state[np.newaxis, :])[0]
action = np.maximum(np.random.normal(action, self.eps, action.shape), np.ones_like(action) * 1e-3)
Ao executar esses códigos, encontrei uma exceção do Tensorflow:
Using TensorFlow backend.
create_actor_network
Exception in thread Thread-1:
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "/Users/niyan/code/routerRL/A3C.py", line 26, in run
action = self.actor.model.predict(state[np.newaxis, :])[0]
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/keras/engine/training.py", line 1269, in predict
self._make_predict_function()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/keras/engine/training.py", line 798, in _make_predict_function
**kwargs)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/keras/backend/tensorflow_backend.py", line 1961, in function
return Function(inputs, outputs, updates=updates)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/keras/backend/tensorflow_backend.py", line 1919, in __init__
with tf.control_dependencies(self.outputs):
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 3583, in control_dependencies
return get_default_graph().control_dependencies(control_inputs)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 3314, in control_dependencies
c = self.as_graph_element(c)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 2405, in as_graph_element
return self._as_graph_element_locked(obj, allow_tensor, allow_operation)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 2484, in _as_graph_element_locked
raise ValueError("Tensor %s is not an element of this graph." % obj)
ValueError: Tensor Tensor("concat:0", shape=(?, 4), dtype=float32) is not an element of this graph.
Então, como posso usar um modelo Keras treinado (usando o Tensorflow como back-end) para prever simultaneamente em vários threads?
Atualização em 2 de abril: tentei lidar com o modelo por causa do peso, mas não funcionou:
for roundNo in xrange(self.param['max_round']):
for agent in self.AgentPool:
agent.syncModel(self.getEnv(), self.actor, self.critic, eps)
agent.start()
for agent in self.AgentPool:
agent.join()
def syncModel(self, env_, actor_, critic_, eps_):
"""synchronize A-C models before collecting data"""
# TODO copy env, actor, critic
self.env = env_ # shallow copy
self.actor.model.set_weights(actor_.model.get_weights()) # deep copy, by weights
self.critic.model.set_weights(critic_.model.get_weights()) # deep copy, by weights
self.eps = eps_ # shallow copy
self.data = {}
EDIT: veja issojaara / blog-AI no Github, parece
model._make_predict_function() # have to initialize before threading
trabalho.
O autor explicou um pouco sobreesse problema. Para uma discussão mais aprofundada, consulteesse problema no Keras