{"id":5271,"date":"2023-06-11T00:42:17","date_gmt":"2023-06-10T15:42:17","guid":{"rendered":"https:\/\/obenkyolab.com\/?p=5271"},"modified":"2023-06-11T00:42:18","modified_gmt":"2023-06-10T15:42:18","slug":"pytorch%e3%81%aetensor%e3%81%aerequires_grad%e3%81%8ctrue%e3%81%ab%e3%81%aa%e3%82%8b%e3%81%a8%e3%81%8d","status":"publish","type":"post","link":"https:\/\/obenkyolab.com\/?p=5271","title":{"rendered":"Pytorch\u306etensor\u306erequires_grad\u304cTrue\u306b\u306a\u308b\u3068\u304d"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/obenkyolab.com\/?p=5271\/#%E6%A6%82%E8%A6%81\" >\u6982\u8981<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/obenkyolab.com\/?p=5271\/#%E6%A4%9C%E8%A8%BC%E7%92%B0%E5%A2%83\" >\u691c\u8a3c\u74b0\u5883<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/obenkyolab.com\/?p=5271\/#requires_grad%E3%81%8CTrue%E3%81%A7%E3%81%AA%E3%81%84%E3%81%A8%E3%81%A9%E3%81%86%E3%81%AA%E3%82%8B%E3%81%8B\" >requires_grad\u304cTrue\u3067\u306a\u3044\u3068\u3069\u3046\u306a\u308b\u304b<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/obenkyolab.com\/?p=5271\/#requires_gradTrue%E3%82%92%E5%AE%A3%E8%A8%80%E3%81%97%E3%81%AA%E3%81%8F%E3%81%A6%E3%82%82backward%E3%81%A7%E3%81%8D%E3%82%8B%E5%A0%B4%E5%90%88\" >requires_grad=True\u3092\u5ba3\u8a00\u3057\u306a\u304f\u3066\u3082backward\u3067\u304d\u308b\u5834\u5408<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%A6%82%E8%A6%81\"><\/span>\u6982\u8981<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Pytorch\u3067\u30cb\u30e5\u30fc\u30e9\u30eb\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u306e\u5b66\u7fd2\u3092\u884c\u3046\u969b\u306b\u91cd\u8981\u306a\u8aa4\u5dee\u9006\u4f1d\u64ad\u3092\u884c\u3046\u305f\u3081\u306e\u30e1\u30bd\u30c3\u30c9\u3068\u3057\u3066Tensor.backward()\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306ebackward\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u306b\u306f\u4f7f\u7528\u3059\u308bTensor\u3067requires_grad=True\u3092\u8a2d\u5b9a\u3057\u3001\u52fe\u914d\u3092\u8a18\u9332\u3055\u305b\u3066\u304a\u304f\u5fc5\u8981\u304c\u3042\u308b\u3068\u3044\u3046\u3053\u3068\u304cPytorch\u306e\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u3082\u66f8\u304b\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p><a href=\"https:\/\/pytorch.org\/docs\/stable\/notes\/autograd.html#:~:text=requires_grad%20is%20a%20flag%2C%20defaulting%20to%20false%20unless,least%20one%20of%20its%20input%20tensors%20require%20grad.\">Autograd mechanics \u2014 PyTorch 2.0 documentation<\/a><\/p>\n\n\n\n<p>\u3057\u304b\u3057\u3001\u3044\u308d\u3093\u306a\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u898b\u308b\u3068\u3001requires_grad=True\u3092\u8a2d\u5b9a\u305b\u305a\u306bbackward\u3092\u4f7f\u7528\u3057\u3066\u3044\u308b\u5834\u5408\u304c\u3042\u308a\u3001\u306a\u305c\u305d\u308c\u3089\u304c\u6b63\u3057\u304f\u52d5\u4f5c\u3057\u3066\u3044\u308b\u306e\u304b\u7591\u554f\u3067\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u4f8b\u3048\u3070\u3053\u3061\u3089\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u3088\u3046\u306a\u4f8b\u3067\u3059\u3002<\/p>\n\n\n\n<p><a href=\"https:\/\/github.com\/christianversloot\/machine-learning-articles\/blob\/main\/how-to-create-a-neural-network-for-regression-with-pytorch.md\">machine-learning-articles\/how-to-create-a-neural-network-for-regression-with-pytorch.md at main \u00b7 christianversloot\/machine-learning-articles \u00b7 GitHub<\/a><\/p>\n\n\n\n<p>\u4eca\u56de\u306f\u305d\u306e\u7406\u7531\u306b\u3064\u3044\u3066\u8abf\u3079\u3066\u307f\u305f\u3053\u3068\u3092\u8a18\u8f09\u3057\u3066\u304a\u3053\u3046\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%A4%9C%E8%A8%BC%E7%92%B0%E5%A2%83\"><\/span>\u691c\u8a3c\u74b0\u5883<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Python 3.8.10<\/p>\n\n\n\n<p>Pytorch 2.0.1<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"requires_grad%E3%81%8CTrue%E3%81%A7%E3%81%AA%E3%81%84%E3%81%A8%E3%81%A9%E3%81%86%E3%81%AA%E3%82%8B%E3%81%8B\"><\/span>requires_grad\u304cTrue\u3067\u306a\u3044\u3068\u3069\u3046\u306a\u308b\u304b<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u307e\u305a\u3001requires_grad\u304cTrue\u3067\u306a\u3044\u5834\u5408\u306bbackward\u3092\u884c\u3046\u3068\u3069\u3046\u306a\u308b\u304b\u3092\u8a66\u3057\u3066\u307f\u307e\u3059\u3002tensor\u3092\u5b9a\u7fa9\u3057\u305f\u969b\u3001\u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u306frequires_grad\u306fFalse\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-python\" data-lang=\"Python\"><code>import torch\nx = torch.tensor([[1., -1.], [1., -1.]])\ny = x.sum()\nprint(y.requires_grad)<\/code><\/pre><\/div>\n\n\n\n<pre class=\"wp-block-preformatted has-white-color has-black-background-color has-text-color has-background\">False<\/pre>\n\n\n\n<p>\u3053\u306e\u72b6\u614b\u3067backward\u3092\u884c\u3063\u3066\u307f\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-python\" data-lang=\"Python\"><code>y.backward()<\/code><\/pre><\/div>\n\n\n\n<p>\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30a8\u30e9\u30fc\u304c\u767a\u751f\u3057\u3066backward\u3092\u884c\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted has-white-color has-black-background-color has-text-color has-background\"><strong>RuntimeError<\/strong>: element 0 of tensors does not require grad and does not have a grad_fn<\/pre>\n\n\n\n<p>\u3057\u304b\u3057\u3001Tensor\u3092\u5ba3\u8a00\u3059\u308b\u969b\u306brequires_grad=True\u3092\u8a2d\u5b9a\u3057\u3066\u304a\u304f\u3068\u3001\u554f\u984c\u306a\u304fbackward\u3092\u884c\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u306e\u5834\u5408\u306f\u30a8\u30e9\u30fc\u304c\u767a\u751f\u3057\u307e\u305b\u3093\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-python\" data-lang=\"Python\"><code>import torch\nx = torch.tensor([[1., -1.], [1., -1.]], requires_grad=True)\ny = x.sum()\ny.backward()<\/code><\/pre><\/div>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"requires_gradTrue%E3%82%92%E5%AE%A3%E8%A8%80%E3%81%97%E3%81%AA%E3%81%8F%E3%81%A6%E3%82%82backward%E3%81%A7%E3%81%8D%E3%82%8B%E5%A0%B4%E5%90%88\"><\/span>requires_grad=True\u3092\u5ba3\u8a00\u3057\u306a\u304f\u3066\u3082backward\u3067\u304d\u308b\u5834\u5408<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u3057\u304b\u3057\u3001\u5192\u982d\u3067\u8ff0\u3079\u3066\u3044\u308b\u901a\u308a\u3001requires_grad=True\u3092\u8a2d\u5b9a\u3057\u306a\u304f\u3066\u3082backward\u3067\u304d\u3066\u3044\u308b\u30b3\u30fc\u30c9\u304c\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u306frequires_grad=Ture\u3092\u6700\u521d\u306eTensor\u3067\u8a2d\u5b9a\u3057\u3066\u3044\u307e\u305b\u3093\u304c\u3001backward\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-python\" data-lang=\"Python\"><code>import torch\nimport torch.nn as nn\n\n# requires_grad=True\u3092\u8a2d\u5b9a\u3057\u3066\u3044\u306a\u3044\nx = torch.tensor([[1., -1.], [1., -1.]])\n\nmodel = nn.Sequential(\n    nn.Linear(2, 4),\n    nn.ReLU(),\n    nn.Linear(4, 1)\n)\n\ny = model(x).sum()\n\ny.backward()<\/code><\/pre><\/div>\n\n\n\n<p>backward\u3067\u304d\u308b\u7406\u7531\u3068\u3057\u3066\u306fnn.Sequential()\u306e\u304a\u304b\u3052\u3067\u3059\u3002<\/p>\n\n\n\n<p>nn.Sequential()\u3092\u901a\u3059\u3053\u3068\u3067\u305d\u306e\u51fa\u529b\u306etensor\u304c\u81ea\u52d5\u7684\u306brequires_grad\u304cTrue\u306b\u8a2d\u5b9a\u3055\u308c\u307e\u3059\u3002\u4ee5\u4e0b\u304c\u305d\u306e\u78ba\u8a8d\u306e\u30b3\u30fc\u30c9\u3067\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-python\" data-lang=\"Python\"><code>import torch\nimport torch.nn as nn\nx = torch.tensor([[1., -1.], [1., -1.]])\n\nprint(&quot;x.requires_grad is &quot;, x.requires_grad)\n\nmodel = nn.Sequential(\n    nn.Linear(2, 4),\n    nn.ReLU(),\n    nn.Linear(4, 1)\n)\n\nprint(&quot;model(x).requires_grad is &quot;, model(x).requires_grad)\n\ny = model(x).sum()\n\nprint(&quot;y.requires_grad is &quot;, y.requires_grad)\n\ny.backward()<\/code><\/pre><\/div>\n\n\n\n<pre class=\"wp-block-preformatted has-white-color has-black-background-color has-text-color has-background\">x.requires_grad is  False\nmodel(x).requires_grad is  True\ny.requires_grad is  True<\/pre>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306bnn.Sequential()\u3067\u5b9a\u7fa9\u3057\u305f\u30e2\u30c7\u30eb\u306e\u51fa\u529b\u306f\u81ea\u52d5\u7684\u306brequires_grad=True\u306b\u306a\u3063\u3066\u3044\u308b\u3068\u601d\u308f\u308c\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u308f\u3056\u308f\u3056tensor\u5b9a\u7fa9\u6642\u306b\u8a2d\u5b9a\u3059\u308b\u5fc5\u8981\u304c\u306a\u304fbackward\u304c\u52d5\u4f5c\u3057\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6982\u8981 Pytorch\u3067\u30cb\u30e5\u30fc\u30e9\u30eb\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u306e\u5b66\u7fd2\u3092\u884c\u3046\u969b\u306b\u91cd\u8981\u306a\u8aa4&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":1218,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_locale":"ja","_original_post":"https:\/\/obenkyolab.com\/?p=5271","footnotes":""},"categories":[7,53],"tags":[],"class_list":["post-5271","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-python","category-53","ja"],"_links":{"self":[{"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/posts\/5271","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5271"}],"version-history":[{"count":2,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/posts\/5271\/revisions"}],"predecessor-version":[{"id":5273,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/posts\/5271\/revisions\/5273"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=\/wp\/v2\/media\/1218"}],"wp:attachment":[{"href":"https:\/\/obenkyolab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5271"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5271"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/obenkyolab.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5271"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}