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 | from torchvision import datasets, models, transformsimport os
 from torch.autograd import Variable
 import torch.utils.data
 import random
 import matplotlib.pyplot as plt
 from PIL import Image
 import numpy as np
 
 data_dir = "E:/trains/CatsVSDogs"
 
 data_trainsforms = {
 "train": transforms.Compose([
 transforms.RandomResizedCrop(300),
 transforms.Resize((224, 224)),
 transforms.RandomCrop((224, 224)),
 transforms.RandomHorizontalFlip(),
 transforms.ToTensor(),
 transforms.Normalize([0.5, 0.5, 0.5], [0.5, 0.5, 0.5]),
 ]),
 
 "test": transforms.Compose([
 transforms.RandomResizedCrop(300),
 transforms.RandomHorizontalFlip(),
 transforms.Resize((224, 224)),
 transforms.ToTensor(),
 transforms.Normalize([0.5, 0.5, 0.5], [0.5, 0.5, 0.5]),
 ]), }
 
 
 image_datasets = {
 x: datasets.ImageFolder(root=os.path.join(data_dir, x),
 transform=data_trainsforms[x])
 for x in ["train", "test"]
 }
 
 data_loader = {x: torch.utils.data.DataLoader(image_datasets[x], batch_size=20, shuffle=True) for x in
 ["train", "test"]}
 
 X_example, y_example = next(iter(data_loader["train"]))
 example_classees = image_datasets["train"].classes
 index_classes = image_datasets["train"].class_to_idx
 
 
 model = models.resnet50(pretrained=True)
 
 Use_gpu = torch.cuda.is_available()
 
 for parma in model.parameters():
 parma.requires_grad = False
 model.fc = torch.nn.Linear(2048, 2)
 
 if Use_gpu:
 model = model.cuda()
 
 
 loss_f = torch.nn.CrossEntropyLoss()
 optimizer = torch.optim.Adam(model.fc.parameters(), lr=0.00001)
 
 epoch_n = 5
 
 for epoch in range(epoch_n):
 print("Epoch {}/{}".format(epoch + 1, epoch_n))
 print("-" * 10)
 
 for phase in ["train", "test"]:
 if phase == "train":
 print("训练中。。。")
 model.train(True)
 else:
 print("测试中。。。")
 model.train(False)
 running_loss = 0.0
 running_corrects = 0
 
 for batch, data in enumerate(data_loader[phase], 1):
 X, y = data
 if Use_gpu:
 X, y = Variable(X.cuda()), Variable(y.cuda())
 else:
 X, y = Variable(X), Variable(y)
 
 y_pred = model(X)
 
 _, pred = torch.max(y_pred.data, 1)
 optimizer.zero_grad()
 loss = loss_f(y_pred, y)
 if phase == "train":
 loss.backward()
 optimizer.step()
 running_loss += loss.item()
 running_corrects += torch.sum(pred == y.data)
 if batch % 500 == 0 and phase == "train":
 print("Batch{},训练损失率:{:.4f},训练正确率:{:.4f}".format(batch, running_loss / batch,
 100 * running_corrects / (20 * batch)))
 epoch_loss = running_loss * 20 / len(image_datasets[phase])
 epoch_acc = 100 * running_corrects / len(image_datasets[phase])
 
 print("{} 当前损失率:{:.4f} 当前正确率:{:.4f}%".format(phase, epoch_loss, epoch_acc))
 torch.save(model.state_dict(),'model.ckpt1')
 torch.save(model.state_dict(),'model.pth')
 print("over")
 
 model.load_state_dict(torch.load('model.pth'))
 
 model.eval()
 
 test_images = image_datasets['test'].imgs
 random.shuffle(test_images)
 test_images = test_images[:9]
 
 fig, axs = plt.subplots(nrows=3, ncols=3, figsize=(8, 8))
 fig.suptitle('Model Predictions')
 
 for i, (image_path, label) in enumerate(test_images):
 image = Image.open(image_path)
 image = image.resize((224, 224))
 image = data_trainsforms['test'](image)
 image = image.unsqueeze(0)
 
 if Use_gpu:
 image = image.cuda()
 output = model(image)
 _, predicted = torch.max(output.data, 1)
 predicted_label = example_classees[predicted.item()]
 
 image = image.cpu().numpy()
 
 axs[i//3, i%3].imshow(np.transpose(image.squeeze(), (1, 2, 0)))
 axs[i//3, i%3].axis('off')
 axs[i//3, i%3].set_title(predicted_label)
 
 plt.show()
 
 
 |