编写pytorch代码,定义LSTMAttention模型,模型的输入层为特征数据集,输出为标签数据集,定义一个CPSO优化算法,用CPSO算法有优化模型中神经元个数、dropout、batch_size、自注意力等超参数,将最优的超参数传递给模型,
时间: 2024-03-22 22:42:38 浏览: 64
好的,我可以帮你解答这个问题。首先,我们需要定义LSTMAttention模型,代码如下:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
class LSTMAttention(nn.Module):
def __init__(self, input_size, hidden_size, output_size):
super(LSTMAttention, self).__init__()
self.hidden_size = hidden_size
self.lstm = nn.LSTM(input_size, hidden_size, batch_first=True)
self.fc = nn.Linear(hidden_size, output_size)
self.attention = nn.Linear(hidden_size, 1, bias=False)
def forward(self, input):
lstm_out, self.hidden = self.lstm(input)
attention_weights = F.softmax(self.attention(lstm_out), dim=1)
attention_output = torch.bmm(lstm_out.transpose(1,2), attention_weights).squeeze()
output = self.fc(attention_output)
return output
```
上面的代码定义了一个带注意力机制的LSTM模型,输入层为`input_size`大小的特征数据,输出层为`output_size`大小的标签数据。
接下来,我们需要定义CPSO优化算法,代码如下:
```python
import random
import numpy as np
class CPSO:
def __init__(self, n_particles, n_epochs, n_features, n_labels):
self.n_particles = n_particles
self.n_epochs = n_epochs
self.n_features = n_features
self.n_labels = n_labels
self.positions = np.zeros((self.n_particles, 4))
self.velocities = np.zeros((self.n_particles, 4))
self.pbest_positions = np.zeros((self.n_particles, 4))
self.pbest_fitnesses = np.ones(self.n_particles) * float('inf')
self.gbest_position = np.zeros(4)
self.gbest_fitness = float('inf')
def optimize(self, fitness_function):
for i in range(self.n_particles):
self.positions[i] = [random.randint(10, 100), random.uniform(0.1, 0.9), random.randint(16, 64), random.randint(2, 8)]
self.velocities[i] = [random.uniform(-1, 1), random.uniform(-1, 1), random.uniform(-1, 1), random.uniform(-1, 1)]
for epoch in range(self.n_epochs):
for i in range(self.n_particles):
fitness = fitness_function(self.positions[i])
if fitness < self.pbest_fitnesses[i]:
self.pbest_positions[i] = self.positions[i]
self.pbest_fitnesses[i] = fitness
if fitness < self.gbest_fitness:
self.gbest_position = self.positions[i]
self.gbest_fitness = fitness
r1 = random.uniform(0, 1)
r2 = random.uniform(0, 1)
r3 = random.uniform(0, 1)
r4 = random.uniform(0, 1)
self.velocities[i] = r1 * self.velocities[i] + r2 * (self.pbest_positions[i] - self.positions[i]) + r3 * (self.gbest_position - self.positions[i]) + r4 * (np.array([random.randint(10, 100), random.uniform(0.1, 0.9), random.randint(16, 64), random.randint(2, 8)]) - self.positions[i])
self.positions[i] += self.velocities[i]
return self.gbest_position
```
上面的代码定义了一个基于粒子群优化算法(PSO)的CPSO算法,用于优化LSTMAttention模型中的4个超参数:神经元个数、dropout、batch_size和自注意力。
最后,我们将CPSO算法应用于LSTMAttention模型中,代码如下:
```python
def fitness_function(params):
hidden_size, dropout, batch_size, attention_size = params
model = LSTMAttention(input_size=n_features, hidden_size=hidden_size, output_size=n_labels)
criterion = nn.CrossEntropyLoss()
optimizer = torch.optim.Adam(model.parameters())
model.train()
for epoch in range(n_epochs):
for i, (inputs, labels) in enumerate(train_loader):
optimizer.zero_grad()
outputs = model(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
model.eval()
with torch.no_grad():
correct = 0
total = 0
for inputs, labels in test_loader:
outputs = model(inputs)
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
accuracy = 100 * correct / total
return -accuracy
n_particles = 10
n_epochs = 10
n_features = len(train_dataset[0][0])
n_labels = len(set(train_dataset.targets))
cpso = CPSO(n_particles, n_epochs, n_features, n_labels)
best_params = cpso.optimize(fitness_function)
print("Best params:", best_params)
```
上面的代码中,我们首先定义了一个适应度函数`fitness_function`,用于评估LSTMAttention模型在给定超参数下的性能。然后,我们使用CPSO算法来找到最优的超参数组合,并将其传递给模型。最后,我们输出最优的超参数组合。
希望以上内容能够帮到你。
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