给我一个代码用transformer对我自己建立的时序数据数据集进行二分类检测,输出训练集、验证集、测试集准确率
时间: 2023-06-14 18:04:38 浏览: 339
好的,我可以给你提供一个基于PyTorch的代码框架,用Transformer模型对时序数据进行二分类检测。你可以根据自己的数据集进行一定的修改。
首先,需要安装必要的Python库,包括PyTorch、Numpy、Pandas等。可以使用以下命令安装:
```
pip install torch numpy pandas
```
然后,我们需要准备数据集。假设我们的数据集包含两个类别,每个样本包含10个时序数据,我们可以使用Pandas库读取数据并将其转换为PyTorch Tensor:
```python
import pandas as pd
import numpy as np
import torch
# 读取数据
data = pd.read_csv('data.csv')
# 将数据转换为PyTorch Tensor
x = torch.tensor(data.iloc[:, :-1].values, dtype=torch.float32)
y = torch.tensor(data.iloc[:, -1].values, dtype=torch.long)
```
接下来,我们需要对数据进行划分,以便进行训练、验证和测试。可以使用PyTorch中的SubsetRandomSampler实现:
```python
from torch.utils.data import DataLoader, SubsetRandomSampler
# 定义训练、验证、测试集的比例
train_ratio = 0.6
val_ratio = 0.2
test_ratio = 0.2
# 计算划分后的数据集大小
train_size = int(train_ratio * len(data))
val_size = int(val_ratio * len(data))
test_size = len(data) - train_size - val_size
# 随机划分数据集
indices = np.arange(len(data))
np.random.shuffle(indices)
train_indices = indices[:train_size]
val_indices = indices[train_size:train_size+val_size]
test_indices = indices[train_size+val_size:]
# 定义数据加载器
train_sampler = SubsetRandomSampler(train_indices)
val_sampler = SubsetRandomSampler(val_indices)
test_sampler = SubsetRandomSampler(test_indices)
train_loader = DataLoader(dataset, batch_size=32, sampler=train_sampler)
val_loader = DataLoader(dataset, batch_size=32, sampler=val_sampler)
test_loader = DataLoader(dataset, batch_size=32, sampler=test_sampler)
```
现在,我们可以定义Transformer模型。这里我们使用PyTorch官方的Transformer模型实现:
```python
import torch.nn as nn
from torch.nn import TransformerEncoder, TransformerEncoderLayer
class TransformerModel(nn.Module):
def __init__(self, ntoken, ninp, nhead, nhid, nlayers, dropout=0.5):
super(TransformerModel, self).__init__()
self.model_type = 'Transformer'
self.src_mask = None
self.pos_encoder = PositionalEncoding(ninp, dropout)
encoder_layers = TransformerEncoderLayer(ninp, nhead, nhid, dropout)
self.transformer_encoder = TransformerEncoder(encoder_layers, nlayers)
self.encoder = nn.Embedding(ntoken, ninp)
self.ninp = ninp
self.decoder = nn.Linear(ninp, 2)
self.init_weights()
def _generate_square_subsequent_mask(self, sz):
mask = (torch.triu(torch.ones(sz, sz)) == 1).transpose(0, 1)
mask = mask.float().masked_fill(mask == 0, float('-inf')).masked_fill(mask == 1, float(0.0))
return mask
def init_weights(self):
initrange = 0.1
self.encoder.weight.data.uniform_(-initrange, initrange)
self.decoder.bias.data.zero_()
self.decoder.weight.data.uniform_(-initrange, initrange)
def forward(self, src):
if self.src_mask is None or self.src_mask.size(0) != len(src):
device = src.device
mask = self._generate_square_subsequent_mask(len(src)).to(device)
self.src_mask = mask
src = self.encoder(src) * math.sqrt(self.ninp)
src = self.pos_encoder(src)
output = self.transformer_encoder(src, self.src_mask)
output = output.mean(dim=0)
output = self.decoder(output)
return output
```
接下来,我们可以定义训练和评估函数:
```python
import torch.optim as optim
def train(model, optimizer, criterion, train_loader):
model.train()
total_loss = 0
total_correct = 0
for batch in train_loader:
optimizer.zero_grad()
x, y = batch
y_pred = model(x)
loss = criterion(y_pred, y)
loss.backward()
optimizer.step()
total_loss += loss.item()
total_correct += (y_pred.argmax(dim=1) == y).sum().item()
return total_loss / len(train_loader), total_correct / len(train_loader.dataset)
def evaluate(model, criterion, data_loader):
model.eval()
total_loss = 0
total_correct = 0
with torch.no_grad():
for batch in data_loader:
x, y = batch
y_pred = model(x)
loss = criterion(y_pred, y)
total_loss += loss.item()
total_correct += (y_pred.argmax(dim=1) == y).sum().item()
return total_loss / len(data_loader), total_correct / len(data_loader.dataset)
```
最后,我们可以开始训练模型:
```python
# 定义模型超参数
ntokens = 10
emsize = 128
nhead = 8
nhid = 256
nlayers = 6
dropout = 0.2
# 创建模型、优化器和损失函数
model = TransformerModel(ntokens, emsize, nhead, nhid, nlayers, dropout)
optimizer = optim.Adam(model.parameters(), lr=0.001)
criterion = nn.CrossEntropyLoss()
# 训练模型
for epoch in range(10):
train_loss, train_acc = train(model, optimizer, criterion, train_loader)
val_loss, val_acc = evaluate(model, criterion, val_loader)
print(f'Epoch {epoch+1}: Train Loss={train_loss:.4f}, Train Acc={train_acc:.4f}, Val Loss={val_loss:.4f}, Val Acc={val_acc:.4f}')
# 在测试集上评估模型
test_loss, test_acc = evaluate(model, criterion, test_loader)
print(f'Test Loss={test_loss:.4f}, Test Acc={test_acc:.4f}')
```
这里我们训练了10个epoch,并在测试集上评估了模型。你可以根据自己的数据集和需求调整模型超参数和训练轮数。
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