R语言计算回归模型每个样本(观察、observation、sample)的杠杆值(leverage)实战:如果一个样本的预测变量比其他样本的预测变量值更极端,那么被认为具有很高的杠杆作用

好的,下面是一个使用Python编写的基于PyTorch的强化学习 模型_示例: 首先,需要安装PyTorch和其他必要的库。可以使用以下命令在Python中安装PyTorch: pip install torch 接下来,导入必要的库: python import torch import torch.nn as nn import torch.optim as optim import gym 定义一个神经网络 _模型,该 模型_将接收环境状态,并输出每个可能的行动的 _值。在这个例子中,我们使用两个全连接层和ReLU激活函数。最后一层输出的 值_是行动的Q _值python class DQN(nn.Module): def __init__(self, state_dim, action_dim, hidden_dim): super().__init__() self.fc1 = nn.Linear(state_dim, hidden_dim) self.fc2 = nn.Linear(hidden_dim, hidden_dim) self.fc3 = nn.Linear(hidden_dim, action_dim) def forward(self, x): x = nn.functional.relu(self.fc1(x)) x = nn.functional.relu(self.fc2(x)) x = self.fc3(x) return x 定义一个代理类,该类将实现强化学习代理的行为。在这个例子中,我们使用Deep Q-Network (DQN)算法: python class DQNAgent: def __init__(self, env, state_dim, action_dim, hidden_dim, lr, gamma, epsilon): self.env = env self.state_dim = state_dim self.action_dim = action_dim self.gamma = gamma self.epsilon = epsilon self.net = DQN(state_dim, action_dim, hidden_dim) self.optimizer = optim.Adam(self.net.parameters(), lr=lr) self.loss_fn = nn.MSELoss() def act(self, state): if torch.rand(1) < self.epsilon: return self.env.action_space. _sample_() else: q_values = self.net(torch.FloatTensor(state)) _, action = torch.max(q_values, dim=0) return action.item() def learn(self, batch): states, actions, rewards, next_states, dones = batch q_values = self.net(torch.FloatTensor(states)) next_q_values = self.net(torch.FloatTensor(next_states)) target_q_values = q_values.clone() for i in range(len(actions)): target_q_values[i][actions[i]] = rewards[i] + self.gamma * torch.max(next_q_values[i]) * (1 - dones[i]) loss = self.loss_fn(q_values, target_q_values.detach()) self.optimizer.zero_grad() loss.backward() self.optimizer.step() 最后,我们可以创建一个环境,初始化代理,并开始训练: `python env = gym.make(‘CartPole-v1’) agent = DQNAgent(env, env. _observation__space.shape[0], env.action_space.n, 128, 1e-3, 0.99, 0.1) for episode in range(1000): state = env.reset() done = False total_reward = 0 while not done: action = agent.act(state) next_state, reward, done, info = env.step(action) agent.learn((state, action, reward, next_state, done)) state = next_state total_reward += reward

Original: https://blog.csdn.net/zhongkeyuanchongqing/article/details/120596249
Author: Data+Science+Insight
Title: R语言计算回归模型每个样本(观察、observation、sample)的杠杆值(leverage)实战:如果一个样本的预测变量比其他样本的预测变量值更极端,那么被认为具有很高的杠杆作用

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