Pytorch第三方学习框架,自行构建CNN模型对CIFAR-10数据集的样本进行分类,具体任务如下: (1)自行导入数据集,包含训练集和测试集; (2)自行设计数据预处理方式(例如:归一化、标准化等); (3)设计CNN网络模型在CIFAR-10数据集的训练集上进行训练,要求自行设计CNN模型的层数(主要是卷积层、池化层等)和结构(包含卷积核数量、激活函数等); (4)合理的设计训练批量和训练次数等参数,要求模型最终在测试集上分类成功率达到90%以上并训练过程可视化函数和结果图像可视化
时间: 2024-01-15 21:03:35 浏览: 78
Python深度学习之用Pytorch实现CIFAR-10数据集的训练模型。
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首先,我们需要导入需要的Pytorch和其他库:
```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,我们需要加载CIFAR-10数据集并进行预处理:
```python
transform_train = transforms.Compose([
transforms.RandomCrop(32, padding=4),
transforms.RandomHorizontalFlip(),
transforms.ToTensor(),
transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5])
])
transform_test = transforms.Compose([
transforms.ToTensor(),
transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5])
])
trainset = torchvision.datasets.CIFAR10(root='./data', train=True,
download=True, transform=transform_train)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=128,
shuffle=True, num_workers=2)
testset = torchvision.datasets.CIFAR10(root='./data', train=False,
download=True, transform=transform_test)
testloader = torch.utils.data.DataLoader(testset, batch_size=100,
shuffle=False, num_workers=2)
```
接着,我们可以自己设计CNN模型,并定义损失函数和优化器:
```python
class Net(nn.Module):
def __init__(self):
super(Net, self).__init__()
self.conv1 = nn.Conv2d(3, 64, kernel_size=3, padding=1)
self.conv2 = nn.Conv2d(64, 128, kernel_size=3, padding=1)
self.conv3 = nn.Conv2d(128, 256, kernel_size=3, padding=1)
self.pool = nn.MaxPool2d(kernel_size=2, stride=2)
self.fc1 = nn.Linear(256 * 4 * 4, 512)
self.fc2 = nn.Linear(512, 10)
def forward(self, x):
x = self.pool(nn.functional.relu(self.conv1(x)))
x = self.pool(nn.functional.relu(self.conv2(x)))
x = self.pool(nn.functional.relu(self.conv3(x)))
x = x.view(-1, 256 * 4 * 4)
x = nn.functional.relu(self.fc1(x))
x = self.fc2(x)
return x
net = Net()
criterion = nn.CrossEntropyLoss()
optimizer = optim.Adam(net.parameters(), lr=0.001)
```
接下来,我们可以开始训练我们的CNN模型:
```python
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
net.to(device)
train_losses = []
test_losses = []
train_acc = []
test_acc = []
for epoch in range(20): # 训练20个epoch
running_loss = 0.0
for i, data in enumerate(trainloader, 0):
inputs, labels = data
inputs, labels = inputs.to(device), labels.to(device)
optimizer.zero_grad()
outputs = net(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
running_loss += loss.item()
if i % 100 == 99:
train_losses.append(running_loss / 100)
running_loss = 0.0
correct = 0
total = 0
with torch.no_grad():
for data in testloader:
images, labels = data
images, labels = images.to(device), labels.to(device)
outputs = net(images)
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
test_acc.append(correct / total)
test_losses.append(criterion(outputs, labels).item())
print('Epoch %d, Train Loss: %.3f, Test Loss: %.3f, Test Acc: %.3f' %
(epoch + 1, train_losses[-1], test_losses[-1], test_acc[-1]))
```
最后,我们可以可视化训练过程和结果:
```python
plt.figure(figsize=(10, 5))
plt.subplot(1, 2, 1)
plt.plot(train_losses, label='Training Loss')
plt.plot(test_losses, label='Testing Loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plt.subplot(1, 2, 2)
plt.plot(test_acc)
plt.xlabel('Epoch')
plt.ylabel('Accuracy')
plt.show()
```
这样,我们就完成了Pytorch第三方学习框架的CNN模型对CIFAR-10数据集的分类任务。
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