用pytorch写一个fashionmnist分类设计代码进行识别生成预测曲线图和训练曲线图
时间: 2024-05-06 12:15:36 浏览: 14
好的,以下是基于PyTorch的Fashion-MNIST分类的代码,包括训练过程中的预测曲线图和训练曲线图。
首先,我们需要导入所需的库:
```python
import torch
import torch.nn as nn
import torch.optim as optim
import torchvision
import torchvision.transforms as transforms
import matplotlib.pyplot as plt
import numpy as np
```
然后,我们需要定义数据集和数据加载器:
```python
# 定义数据预处理的转换
transform = transforms.Compose(
[transforms.ToTensor(),
transforms.Normalize((0.5,), (0.5,))])
# 加载训练集和测试集
trainset = torchvision.datasets.FashionMNIST(root='./data', train=True,
download=True, transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4,
shuffle=True, num_workers=2)
testset = torchvision.datasets.FashionMNIST(root='./data', train=False,
download=True, transform=transform)
testloader = torch.utils.data.DataLoader(testset, batch_size=4,
shuffle=False, num_workers=2)
# 定义类别名称
classes = ('T-shirt/top', 'Trouser', 'Pullover', 'Dress',
'Coat', 'Sandal', 'Shirt', 'Sneaker', 'Bag', 'Ankle boot')
```
接下来,我们需要定义模型:
```python
class Net(nn.Module):
def __init__(self):
super(Net, self).__init__()
self.conv1 = nn.Conv2d(1, 6, 5)
self.pool = nn.MaxPool2d(2, 2)
self.conv2 = nn.Conv2d(6, 16, 5)
self.fc1 = nn.Linear(16 * 4 * 4, 120)
self.fc2 = nn.Linear(120, 84)
self.fc3 = nn.Linear(84, 10)
def forward(self, x):
x = self.pool(torch.relu(self.conv1(x)))
x = self.pool(torch.relu(self.conv2(x)))
x = x.view(-1, 16 * 4 * 4)
x = torch.relu(self.fc1(x))
x = torch.relu(self.fc2(x))
x = self.fc3(x)
return x
net = Net()
```
然后,我们需要定义损失函数和优化器:
```python
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(net.parameters(), lr=0.001, momentum=0.9)
```
接下来,我们可以开始训练过程:
```python
# 训练模型
losses = []
accuracies = []
epochs = 10
for epoch in range(epochs):
running_loss = 0.0
total_loss = 0.0
correct = 0.0
total = 0.0
for i, data in enumerate(trainloader, 0):
# 获取输入数据
inputs, labels = data
# 梯度清零
optimizer.zero_grad()
# 前向传播、反向传播、优化
outputs = net(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
# 统计损失和准确率
running_loss += loss.item()
total_loss += loss.item()
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
# 每2000个mini-batch打印一次信息
if i % 2000 == 1999:
print('[%d, %5d] loss: %.3f' %
(epoch + 1, i + 1, running_loss / 2000))
running_loss = 0.0
# 记录训练过程中的损失和准确率
losses.append(total_loss / len(trainset))
accuracies.append(100.0 * correct / total)
print('Finished Training')
```
最后,我们可以使用测试集来评估模型的性能,并绘制预测曲线图和训练曲线图:
```python
# 测试模型
correct = 0.0
total = 0.0
with torch.no_grad():
for data in testloader:
inputs, labels = data
outputs = net(inputs)
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
print('Accuracy of the network on the 10000 test images: %d %%' % (
100 * correct / total))
# 绘制预测曲线图
images, labels = iter(testloader).next()
outputs = net(images)
_, predicted = torch.max(outputs, 1)
fig, ax = plt.subplots(figsize=(8, 4))
ax.plot(np.arange(len(classes)), np.zeros(len(classes)), 'o', label='True')
ax.plot(np.arange(len(classes)), np.zeros(len(classes)), 'x', label='Predicted')
ax.set_xticks(np.arange(len(classes)))
ax.set_xticklabels(classes, rotation=45)
ax.set_ylim([0, 1.1])
ax.legend()
for i in range(len(images)):
ax.plot(labels[i], 0, 'o', color='blue')
ax.plot(predicted[i], 0, 'x', color='red')
plt.show()
# 绘制训练曲线图
fig, ax1 = plt.subplots()
color = 'tab:red'
ax1.set_xlabel('Epoch')
ax1.set_ylabel('Loss', color=color)
ax1.plot(np.arange(epochs), losses, color=color)
ax1.tick_params(axis='y', labelcolor=color)
ax2 = ax1.twinx()
color = 'tab:blue'
ax2.set_ylabel('Accuracy', color=color)
ax2.plot(np.arange(epochs), accuracies, color=color)
ax2.tick_params(axis='y', labelcolor=color)
fig.tight_layout()
plt.show()
```
这样就完成了Fashion-MNIST分类的代码,并且绘制了预测曲线图和训练曲线图。