{"id":391,"date":"2025-03-08T20:50:08","date_gmt":"2025-03-08T12:50:08","guid":{"rendered":"https:\/\/www.bertzzz-horizon.xyz\/?p=391"},"modified":"2025-03-17T19:08:34","modified_gmt":"2025-03-17T11:08:34","slug":"%e9%82%a3%e6%98%af%e9%a3%9e%e6%9c%ba%e5%90%97-%e5%9f%ba%e4%ba%8epytorch%e7%9a%84%e7%ae%80%e6%98%93%e5%88%86%e7%b1%bb%e5%99%a8","status":"publish","type":"post","link":"https:\/\/www.bertzzz-horizon.xyz\/?p=391","title":{"rendered":"&#8220;\u90a3\u662f\u98de\u673a\u5417?&#8221;\u2014\u2014\u57fa\u4e8ePytorch\u7684\u7b80\u6613\u5206\u7c7b\u5668"},"content":{"rendered":"\n<p><\/p>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p>CIFAR-10 \u662f\u7531 Hinton \u7684\u5b66\u751f Alex Krizhevsky \u548c Ilya Sutskever \u6574\u7406\u7684\u4e00\u4e2a\u7528\u4e8e\u8bc6\u522b\u666e\u9002\u7269\u4f53\u7684\u5c0f\u578b\u6570\u636e\u96c6\u3002\u4e00\u5171\u5305\u542b 10 \u4e2a\u7c7b\u522b\u7684 RGB \u5f69\u8272\u56fe \u7247\uff1a\u98de\u673a\uff08 airplane \uff09\u3001\u6c7d\u8f66\uff08 automobile \uff09\u3001\u9e1f\u7c7b\uff08 bird \uff09\u3001\u732b\uff08 cat \uff09\u3001\u9e7f\uff08 deer \uff09\u3001\u72d7\uff08 dog \uff09\u3001\u86d9\u7c7b\uff08 frog \uff09\u3001\u9a6c\uff08 horse \uff09\u3001\u8239\uff08 ship \uff09\u548c\u5361\u8f66\uff08 truck \uff09\u3002\u56fe\u7247\u7684\u5c3a\u5bf8\u4e3a 32\u00d732 \uff0c\u6570\u636e\u96c6\u4e2d\u4e00\u5171\u6709 50000 \u5f20\u8bad\u7ec3\u56fe\u7247\u548c 10000 \u5f20\u6d4b\u8bd5\u56fe\u7247\u3002<\/p>\n<\/blockquote>\n\n\n\n<p>\u9996\u5148\u51c6\u5907\u597d\u6570\u636e\u96c6\u3002\u4f7f\u7528torchvision.datasets\u53ef\u4ee5\u76f4\u63a5\u4e0b\u8f7d\u6570\u636e\u96c6\uff0c\u4f7f\u7528download\u53c2\u6570\u63a7\u5236\u3002\u5f53\u6b64\u9879\u53c2\u6570\u4e3aTrue\uff0c\u5219\u6570\u636e\u96c6\u4e0d\u5b58\u5728\u6307\u5b9a\u76ee\u5f55\u4e0b\u65f6\u4f1a\u81ea\u52a8\u4e0b\u8f7d\u3002\u540c\u65f6\u4f7f\u7528transform.Normalize()\u53ef\u4ee5\u5f88\u597d\u5730\u8fdb\u884c\u5f52\u4e00\u5316\u3002\u5c06transforms.ToTensor()\u4e0e\u5176\u4f7f\u7528transforms.Compose()\u7ed3\u5408\u5728\u4e00\u8d77\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"python\" class=\"language-python\">data_path = r\".\/datasets\"\ncifar10 = datasets.CIFAR10(data_path, train=True, download=True)\ncifar10_val = datasets.CIFAR10(data_path, train=False, download=True)\n\ntensor_cifar10 = datasets.CIFAR10(data_path, train=True, download=False, transform=transforms.ToTensor())\ntensor_cifar10_val = datasets.CIFAR10(data_path, train=False, download=False, transform=transforms.ToTensor())\n\nimg_t, _ = tensor_cifar10[99]\nimgs = torch.stack([img_t for img_t, _ in tensor_cifar10], dim = 3)\n\n'''\nNormalize params are from\nimgs.view(3, -1).mean(dim=1) and imgs.view(3, -1).std(dim=1)\n'''\n\ntransformed_cifar10 = datasets.CIFAR10(data_path,\n                                       train=True,\n                                       download=False,\n                                       transform=transforms.Compose([transforms.ToTensor(),\n                                                                    transforms.Normalize((0.4914, 0.4822, 0.4465),\n                                                                                         (0.2470, 0.2435, 0.2616))]))\ntransformed_cifar10_val = datasets.CIFAR10(data_path,\n                                       train=False,\n                                       download=False,\n                                       transform=transforms.Compose([transforms.ToTensor(),\n                                                                    transforms.Normalize((0.4914, 0.4822, 0.4465),\n                                                                                         (0.2470, 0.2435, 0.2616))]))<\/code><\/pre>\n\n\n\n<p>\u7531\u4e8e\u6211\u4eec\u53ea\u9700\u8981\u5206\u7c7b\u9e1f\u4e0e\u98de\u673a\uff0c\u6211\u4eec\u53ea\u53d6\u9700\u8981\u7684\u6570\u636e\u3002\u5e76\u7528dataloader\u52a0\u8f7d\u6570\u636e\u96c6\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"python\" class=\"language-python\">label_map = {0: 0, 2: 1}\nclass_names = {'airplane', 'bird'}\ncifar2 = [(img, label_map[label])\n          for img, label in transformed_cifar10\n          if label in [0, 2]]\n\ncifar2_val = [(img, label_map[label])\n              for img, label in transformed_cifar10_val\n              if label in [0, 2]]\n\ntrain_loader = torch.utils.data.DataLoader(cifar2, batch_size=64, shuffle=True)\nval_loader = torch.utils.data.DataLoader(cifar2_val, batch_size=64, shuffle=False)<\/code><\/pre>\n\n\n\n<p>\u5b9a\u4e49\u6211\u4eec\u7684\u6a21\u578b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"python\" class=\"language-python\">model = nn.Sequential(nn.Linear(3072,512, ),\n                      nn.Tanh(),\n                      nn.Linear(512, 2, ),\n                      nn.LogSoftmax(dim = 1))<\/code><\/pre>\n\n\n\n<p>\u4e86\u89e3\u5176\u4e2d\u7684Softmax\u51fd\u6570\u662f\u5fc5\u8981\u7684\u3002<\/p>\n\n\n\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Softmax_function\">Softmax\u51fd\u6570\u5b9a\u4e49<\/a><\/p>\n\n\n\n<p>\u4f18\u5316\u8fd9\u4e2a\u6a21\u578b\u6700\u7b80\u5355\u7c97\u66b4\u7684\u529e\u6cd5\u5c31\u662f\u589e\u52a0\u5c42\u6570\u3002\u6700\u540e\u8fdb\u5165\u8bad\u7ec3\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"python\" class=\"language-python\">loss_fn = nn.NLLLoss()\nlearning_rate = 1e-2\noptimizer = torch.optim.SGD(model.parameters(), lr=learning_rate)\nn_epochs = 100\n\n# Train the model\nfor epoch in range(n_epochs):\n    for imgs, labels in train_loader:\n        batch_size = imgs.size(0)\n        outputs = model(imgs.view(batch_size, -1))\n        loss = loss_fn(outputs, labels)\n\n        optimizer.zero_grad()\n        loss.backward()\n        optimizer.step()\n\n    print(\"Epoch: %d, Loss: %f\" % (epoch, float(loss)))<\/code><\/pre>\n\n\n\n<p>\u6211\u4eec\u53ef\u4ee5\u8bc4\u4f30\u4e00\u4e0b\u901a\u8fc7\u6b64\u8bad\u7ec3\u51fa\u7684\u6a21\u578b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"python\" class=\"language-python\">with torch.no_grad():\n    for imgs, labels in val_loader:\n        batch_size = imgs.size(0)\n        outputs = model(imgs.view(batch_size, -1))\n        _, predicted = torch.max(outputs, dim = 1)\n        total += labels.size(0)\n        correct += int((predicted == labels).sum())<\/code><\/pre>\n\n\n\n<p>\u51c6\u786e\u5ea6\u57280.82\u5de6\u53f3\uff0c\u76f8\u5bf9\u6765\u8bf4\u8fd8\u662f\u4e0d\u9519\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CIFAR-10 \u662f\u7531 Hinton \u7684\u5b66\u751f Alex Krizhevsky \u548c Ilya Sutskever [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":392,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_jetpack_memberships_contains_paid_content":false},"categories":[9,11],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/www.bertzzz-horizon.xyz\/wordpress\/wp-content\/uploads\/2025\/03\/isthataplane.png","_links":{"self":[{"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/posts\/391"}],"collection":[{"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=391"}],"version-history":[{"count":31,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/posts\/391\/revisions"}],"predecessor-version":[{"id":472,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/posts\/391\/revisions\/472"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=\/wp\/v2\/media\/392"}],"wp:attachment":[{"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bertzzz-horizon.xyz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}