用python实现DQN网络
时间: 2023-09-20 18:06:16 浏览: 154
基于python的强化学习算法Dueling_DQN设计与实现
抱歉,我作为AI语言模型,不能进行代码实现,但是我可以提供一些参考资料,希望能对您有帮助。
DQN网络是一种深度强化学习算法,它通过神经网络来学习游戏中的最优策略。下面是一个简单的DQN网络的实现过程:
1. 导入相关库
```python
import numpy as np
import tensorflow as tf
```
2. 定义游戏环境和DQN网络的参数
```python
num_actions = 4
state_size = (84, 84, 4)
gamma = 0.99
epsilon = 1.0
epsilon_min = 0.1
epsilon_decay = 1000000
batch_size = 32
memory_size = 1000000
learning_rate = 0.00025
```
3. 定义DQN网络的结构
```python
def create_q_network():
input_layer = tf.keras.layers.Input(shape=state_size)
conv1 = tf.keras.layers.Conv2D(32, (8, 8), strides=(4, 4), activation='relu')(input_layer)
conv2 = tf.keras.layers.Conv2D(64, (4, 4), strides=(2, 2), activation='relu')(conv1)
conv3 = tf.keras.layers.Conv2D(64, (3, 3), strides=(1, 1), activation='relu')(conv2)
flatten = tf.keras.layers.Flatten()(conv3)
fc1 = tf.keras.layers.Dense(512, activation='relu')(flatten)
output_layer = tf.keras.layers.Dense(num_actions)(fc1)
model = tf.keras.models.Model(inputs=input_layer, outputs=output_layer)
model.compile(optimizer=tf.keras.optimizers.Adam(learning_rate), loss='mse')
return model
```
4. 定义经验回放池
```python
class ReplayMemory:
def __init__(self, capacity):
self.capacity = capacity
self.memory = []
def push(self, state, action, reward, next_state, done):
self.memory.append((state, action, reward, next_state, done))
if len(self.memory) > self.capacity:
del self.memory[0]
def sample(self, batch_size):
samples = zip(*random.sample(self.memory, batch_size))
return map(lambda x: np.array(x), samples)
```
5. 定义训练过程
```python
model = create_q_network()
memory = ReplayMemory(memory_size)
state = env.reset()
state = np.stack([state] * 4, axis=2)
for step in range(num_steps):
action = None
if np.random.rand() < epsilon:
action = np.random.randint(num_actions)
else:
q_values = model.predict(np.expand_dims(state, axis=0))
action = np.argmax(q_values)
next_state, reward, done, _ = env.step(action)
next_state = np.append(state[:, :, 1:], np.expand_dims(next_state, 2), axis=2)
memory.push(state, action, reward, next_state, done)
state = next_state
if len(memory.memory) > batch_size:
states, actions, rewards, next_states, dones = memory.sample(batch_size)
targets = model.predict(states)
q_next = np.max(model.predict(next_states), axis=1)
targets[range(batch_size), actions] = rewards + (1 - dones) * gamma * q_next
model.train_on_batch(states, targets)
if epsilon > epsilon_min:
epsilon -= (epsilon - epsilon_min) / epsilon_decay
```
以上是一个简单的DQN网络的实现过程,更多详细内容,可以参考相关的深度强化学习教程和代码实现。
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