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| 1 | +__author__ = 'SherlockLiao' |
| 2 | + |
| 3 | +import torch |
| 4 | +from torch import nn, optim |
| 5 | +from torch.autograd import Variable |
| 6 | +from torch.utils.data import DataLoader |
| 7 | +from torchvision import datasets, transforms |
| 8 | + |
| 9 | +import net |
| 10 | + |
| 11 | +# 超参数(Hyperparameters) |
| 12 | +batch_size = 64 |
| 13 | +learning_rate = 1e-2 |
| 14 | +num_epoches = 20 |
| 15 | + |
| 16 | +# 数据预处理 |
| 17 | +data_tf = transforms.Compose([ |
| 18 | + transforms.ToTensor(), |
| 19 | + transforms.Normalize([0.5, 0.5, 0.5], [0.5, 0.5, 0.5]) |
| 20 | +]) |
| 21 | +# 下载训练集 MNIST 手写数字训练集 |
| 22 | +train_dataset = datasets.MNIST( |
| 23 | + root='./data', train=True, transform=data_tf, download=True) |
| 24 | + |
| 25 | +test_dataset = datasets.MNIST(root='./data', train=False, transform=data_tf) |
| 26 | + |
| 27 | +train_loader = DataLoader(train_dataset, batch_size=batch_size, shuffle=True) |
| 28 | +test_loader = DataLoader(test_dataset, batch_size=batch_size, shuffle=False) |
| 29 | + |
| 30 | +model = net.Batch_Net(28 * 28, 300, 100, 10) |
| 31 | +if torch.cuda.is_available(): |
| 32 | + model = model.cuda() |
| 33 | + |
| 34 | +criterion = nn.CrossEntropyLoss() |
| 35 | +optimizer = optim.SGD(model.parameters(), lr=learning_rate) |
| 36 | + |
| 37 | +for epoch in range(num_epoches): |
| 38 | + print('epoch {}'.format(epoch + 1)) |
| 39 | + print('*' * 10) |
| 40 | + running_loss = 0.0 |
| 41 | + running_acc = 0.0 |
| 42 | + for i, data in enumerate(train_loader, 1): |
| 43 | + img, label = data |
| 44 | + img = img.view(img.size(0), -1) |
| 45 | + if torch.cuda.is_available(): |
| 46 | + img = Variable(img).cuda() |
| 47 | + label = Variable(label).cuda() |
| 48 | + else: |
| 49 | + img = Variable(img) |
| 50 | + label = Variable(label) |
| 51 | + # 向前传播 |
| 52 | + out = model(img) |
| 53 | + loss = criterion(out, label) |
| 54 | + running_loss += loss.data[0] * label.size(0) |
| 55 | + _, pred = torch.max(out, 1) |
| 56 | + num_correct = (pred == label).sum() |
| 57 | + running_acc += num_correct.data[0] |
| 58 | + # 向后传播 |
| 59 | + optimizer.zero_grad() |
| 60 | + loss.backward() |
| 61 | + optimizer.step() |
| 62 | + |
| 63 | + if i % 300 == 0: |
| 64 | + print('[{}/{}] Loss: {:.6f}, Acc: {:.6f}'.format( |
| 65 | + i, |
| 66 | + len(train_loader), running_loss / (batch_size * i), running_acc |
| 67 | + / (batch_size * i))) |
| 68 | + print('Finish {} epoch, Loss: {:.6f}, Acc: {:.6f}'.format( |
| 69 | + epoch + 1, running_loss / (len(train_dataset)), running_acc / (len( |
| 70 | + train_dataset)))) |
| 71 | + |
| 72 | +model.eval() |
| 73 | +eval_loss = 0 |
| 74 | +eval_acc = 0 |
| 75 | +for data in test_loader: |
| 76 | + img, label = data |
| 77 | + img = img.view(img.size(0), -1) |
| 78 | + if torch.cuda.is_available(): |
| 79 | + img = Variable(img, volatile=True).cuda() |
| 80 | + label = Variable(label, volatile=True).cuda() |
| 81 | + else: |
| 82 | + img = Variabel(img, volatile=True) |
| 83 | + label = Variable(label, volatile=True) |
| 84 | + out = model(img) |
| 85 | + loss = criterion(out, label) |
| 86 | + eval_loss += loss.data[0] * label.size(0) |
| 87 | + _, pred = torch.max(out, 1) |
| 88 | + num_correct = (pred == label).sum() |
| 89 | + eval_acc += num_correct.data[0] |
| 90 | +print('Test Loss: {:.6f}, Acc: {:.6f}'.format(eval_loss / (len(test_dataset)), |
| 91 | + eval_acc / (len(test_dataset)))) |
| 92 | +print('save model ...') |
| 93 | + |
| 94 | +# 保存模型 |
| 95 | +torch.save(model.state_dict(), './neural_network.pth') |
| 96 | +print('model saved!') |
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