用中文介绍一下这段代码 def on_epoch_end(self): if self.shuffle == True: self.x, self.label = shuffle(self.x, self.label)
时间: 2024-05-24 16:10:59 浏览: 9
这段代码是一个在训练神经网络模型时使用的回调函数,用于在每个 epoch 结束时执行一些操作。其中,if 语句判断是否需要对数据进行洗牌操作(shuffle),如果需要则调用 shuffle 函数对 self.x 和 self.label 进行洗牌。洗牌操作可以使得模型在训练时更加随机,从而提高模型的泛化能力。
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class Trainer(object): def __init__(self, net, per_num=20, start_num=0, end_num=10, save_path="./model/Lwf", epoch=50, lr=0.0005, batch_size=128): self.lr = lr self.epoch = epoch self.batch_size = batch_size self.strat_num = start_num self.end_num = end_num self.class_num = end_num - start_num self.device = torch.device("cuda" if torch.cuda.is_available() else "cpu") self.save_path = save_path self.main_net_path = save_path + "/LwF_" + str(start_num) + ".pth" transform_train = transforms.Compose([ transforms.RandomCrop(32, padding=4), transforms.RandomHorizontalFlip(), transforms.RandomRotation(10), transforms.ToTensor(), transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5)), ]) transform_test = transforms.Compose([ transforms.ToTensor(), transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5)), ]) trainset = Cifar100Split(start_num=start_num, end_num=end_num, train=True, transform=transform_train) testset = Cifar100Split(start_num=start_num, end_num=end_num, train=False, transform=transform_test) test_all = Cifar100Split(start_num=0, end_num=end_num, train=False, transform=transform_test) self.train_loader = DataLoader(trainset, batch_size=batch_size, shuffle=True, num_workers=0) self.test_loader = DataLoader(testset, batch_size=batch_size, shuffle=False, num_workers=0) self.test_loader_all = DataLoader(test_all, batch_size=batch_size, shuffle=False, num_workers=0)
这段代码是一个PyTorch中的类Trainer的初始化函数。在初始化时,它接受一些参数,包括网络模型net、每个类别的训练样本数per_num、起始类别编号start_num、结束类别编号end_num、保存路径save_path、训练轮数epoch、学习率lr、批量大小batch_size等。此外,该类还定义了一些图像预处理的操作,包括随机裁剪、随机翻转、随机旋转等,并对训练集和测试集进行了划分和加载。该类的作用是训练深度神经网络模型以实现对图像数据的分类任务。
在Begin-End区域中编写代码完成以下任务:使用pytorch搭建出卷积神经网络模型,再对模型进行训练。
```python
import torch
import torch.nn as nn
import torch.optim as optim
# 定义卷积神经网络模型
class ConvNet(nn.Module):
def __init__(self):
super(ConvNet, self).__init__()
self.conv1 = nn.Conv2d(3, 16, 3, padding=1)
self.pool = nn.MaxPool2d(2, 2)
self.conv2 = nn.Conv2d(16, 32, 3, padding=1)
self.fc1 = nn.Linear(32 * 8 * 8, 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, 32 * 8 * 8)
x = torch.relu(self.fc1(x))
x = torch.relu(self.fc2(x))
x = self.fc3(x)
return x
# 加载数据集
trainset = torchvision.datasets.CIFAR10(root='./data', train=True, download=True, transform=transforms.ToTensor())
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4, shuffle=True, num_workers=2)
# 定义损失函数和优化器
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(net.parameters(), lr=0.001, momentum=0.9)
# 训练模型
for epoch in range(2):
running_loss = 0.0
for i, data in enumerate(trainloader, 0):
inputs, labels = data
optimizer.zero_grad()
outputs = net(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
running_loss += loss.item()
if i % 2000 == 1999:
print('[%d, %5d] loss: %.3f' % (epoch + 1, i + 1, running_loss / 2000))
running_loss = 0.0
print('Finished Training')
```
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