{"id":593,"date":"2023-08-03T19:11:23","date_gmt":"2023-08-03T11:11:23","guid":{"rendered":"https:\/\/blog.cirno.fun\/?p=593"},"modified":"2025-03-19T00:31:11","modified_gmt":"2025-03-18T16:31:11","slug":"chap9-%e5%81%8f%e6%96%9c%e7%b1%bb%e7%9a%84%e8%af%af%e5%b7%ae%e5%ba%a6%e9%87%8f","status":"publish","type":"post","link":"https:\/\/blog.sssn.tech\/?p=593","title":{"rendered":"[Chap9]-\u504f\u659c\u7c7b\u7684\u8bef\u5dee\u5ea6\u91cf"},"content":{"rendered":"<h2>\u504f\u659c\u7c7b(Skewed class)<\/h2>\n<p>\u504f\u659c\u7c7b\u6307\u8bad\u7ec3\u96c6\u4e2d\u6709\u975e\u5e38\u591a\u540c\u4e00\u7c7b\u7684\u5b9e\u4f8b,\u4e3e\u4e2a\u4f8b\u5b50:<\/p>\n<p>\u5982\u679c\u6211\u4eec\u5c06\u4e00\u5bb6\u533b\u9662\u7684\u80bf\u7624\u68c0\u6d4b\u6570\u636e\u4f5c\u4e3a\u6570\u636e\u96c6, \u53ef\u80fd\u5927\u90e8\u5206\u6570\u636e\u90fd\u4e0d\u662f\u6076\u884c\u80bf\u7624(\u764c\u75c7), \u6bd4\u5982\u8bf4, \u533b\u9662\u6570\u636e\u4e2d\u53ea\u67090.5%\u7684\u6076\u6027\u80bf\u7624<\/p>\n<p>\u5982\u679c\u6211\u4eec\u7528\u8fd9\u4e9b\u6570\u636e\u8bad\u7ec3\u51fa\u4e00\u4e2a\u6a21\u578b, \u8fd9\u4e2a\u6a21\u578b\u53ea\u4f1a\u505a\u51fa\u4e00\u4e2a\u52a8\u4f5c: \u5224\u65ad\u80bf\u7624\u4e3a\u975e\u6076\u6027. \u8fd9\u663e\u7136\u4e0d\u662f\u4e00\u4e2a\u597d\u6a21\u578b, \u4f46\u662f\u4ed6\u4ecd\u670999%\u7684\u6982\u7387\u4f1a\u5bf9\u4e00\u4e2a\u672a\u77e5\u60c5\u51b5\u7684\u75c5\u4eba\u505a\u51fa\u6b63\u786e\u7684\u5224\u65ad<\/p>\n<p>\u663e\u7136\u6211\u4eec\u4e4b\u524d\u7684\u8861\u91cf\u6a21\u578b\u8868\u73b0\u7684\u6307\u6807\u4e0d\u591f\u5b8c\u5584, \u4e0b\u9762\u7ed9\u51fa\u65b0\u7684\u6307\u6807<\/p>\n<h1>\u67e5\u51c6\u7387(Precision)\u4e0e\u67e5\u5168\u7387(Recall)<\/h1>\n<p>\u6211\u4eec\u5c06\u7b97\u6cd5\u9884\u6d4b\u7684\u7ed3\u679c\u5206\u4e3a\u56db\u79cd\u60c5\u51b5:<\/p>\n<ul>\n<li>\u6b63\u786e\u80af\u5b9a(TP): \u9884\u6d4b\u771f, \u5b9e\u9645\u771f<\/li>\n<li>\u6b63\u786e\u5426\u5b9a(TN): \u9884\u6d4b\u5047, \u5b9e\u9645\u5047<\/li>\n<li>\u9519\u8bef\u80af\u5b9a(FP): \u9884\u6d4b\u771f, \u5b9e\u9645\u5047<\/li>\n<li>\u9519\u8bef\u5426\u5b9a(FN): \u9884\u6d4b\u5047, \u5b9e\u9645\u771f<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/blog.sssn.tech\/wp-content\/uploads\/2023\/08\/image-1691060090281.png\" alt=\"file\" \/><\/p>\n<p>\u5219:<\/p>\n<pre><code class=\"language-katex\">precision = \\frac{TP}{TP+FP} \\\\\nrecall = \\frac{TP}{TP + FN}<\/code><\/pre>\n<p>recall\u4e5f\u53eb\u53ec\u56de\u7387, \u53ef\u4ee5\u5982\u6b64\u5f62\u8c61\u7684\u7406\u89e3, \u5373\u5c06\u6240\u6709\u6837\u672c\u653e\u5f52\u81ea\u7136\u540e, \u7b97\u6cd5\u518d\u6b21\u627e\u51fa\u7684\u6982\u7387<\/p>\n<p>precision\u662f\u5728\u6211\u4eec\u9884\u6d4b\u6709\u80bf\u7624\u7684\u4eba\u4e2d, \u786e\u5b9e\u6709\u80bf\u7624\u7684\u5360\u6bd4 recall\u662f\u6240\u6709\u786e\u5b9e\u6709\u80bf\u7624\u7684\u4eba\u4e2d, \u6211\u4eec\u6210\u529f\u9884\u6d4b\u6709\u80bf\u7624\u7684\u5360\u6bd4<\/p>\n<p>\u8fd9\u6837\u4ee5\u6765, \u4e0a\u8ff0\u7684\u7b97\u6cd5recall\u662f0, \u53cd\u5e94\u4e86\u4ed6\u5728\u8fd9\u65b9\u9762\u8868\u73b0\u5f88\u5dee<\/p>\n<h2>\u67e5\u51c6\u7387\u4e0e\u67e5\u5168\u7387\u7684\u6743\u8861<\/h2>\n<p>\u5728\u504f\u659c\u7c7b\u7684\u5b9e\u9645\u5e94\u7528\u4e2d, \u6211\u4eec\u5e0c\u671b\u5e73\u8861precision\u548crecall, \u6765\u786e\u4fdd\u7b97\u6cd5\u8868\u73b0\u4e0d\u8fc7\u4e8e\u4fdd\u5b88, \u6216\u8005\u6fc0\u8fdb<\/p>\n<p>\u5047\u8bbe\u6211\u4eec\u7528\u903b\u8f91\u56de\u5f52\u89e3\u51b3\u4e0a\u9762\u7684\u95ee\u9898, \u5e76\u4e14\u75280.5\u4f5c\u4e3a\u771f\u5047\u9608\u503c<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.sssn.tech\/wp-content\/uploads\/2023\/08\/image-1691060600451.png\" alt=\"file\" \/><\/p>\n<p>\u5982\u679c\u6211\u4eec\u60f3\u8d8b\u4e8e\u4fdd\u5b88, \u53ea\u5728\u975e\u5e38\u81ea\u4fe1\u65f6\u7ed9\u51fa\u6076\u6027\u80bf\u7624\u7684\u7ed3\u679c, \u53ef\u4ee5\u8bbe\u7f6e\u6bd40.5\u66f4\u5927\u7684\u9608\u503c, \u8fd9\u6837\u505a\u4f1a\u63d0\u9ad8precision<\/p>\n<p>\u5982\u679c\u6211\u4eec\u60f3\u8d8b\u4e8e\u6fc0\u8fdb, \u4e3a\u4e86\u907f\u514d\u53ef\u80fd\u7684\u6f0f\u5224\u80bf\u7624\u5bfc\u81f4\u7684\u4e25\u91cd\u540e\u679c, \u53ef\u4ee5\u964d\u4f4e\u9608\u503c, \u8fd9\u4f1a\u63d0\u9ad8recall<\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u5c06\u9608\u503c-recall, precision\u753b\u6210\u8868, \u66f2\u7ebf\u7684\u5f62\u72b6\u6839\u636e\u6570\u636e\u4e0d\u540c\u4f1a\u6709\u4e0d\u540c<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.sssn.tech\/wp-content\/uploads\/2023\/08\/image-1691060991388.png\" alt=\"file\" \/><\/p>\n<p>\u8fd9\u91cc\u6709\u4e00\u4e2a\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u9009\u62e9\u9608\u503c\u7684\u65b9\u6cd5, F1 score<\/p>\n<pre><code class=\"language-katex\">\nF_1Score=\\frac{2PR}{P+R}\n<\/code><\/pre>\n<p>\u9009\u62e9\u4f7f\u5f97F1\u503c\u6700\u9ad8\u7684\u9608\u503c\u6bd4\u8f83\u5408\u7406<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u504f\u659c\u7c7b(Skewed class) \u504f\u659c\u7c7b\u6307\u8bad\u7ec3\u96c6\u4e2d\u6709\u975e\u5e38\u591a\u540c\u4e00\u7c7b\u7684\u5b9e\u4f8b,\u4e3e\u4e2a\u4f8b [&#8230;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,18],"tags":[],"class_list":["post-593","post","type-post","status-publish","format-standard","hentry","category-11","category-18"],"_links":{"self":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/593","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=593"}],"version-history":[{"count":2,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/593\/revisions"}],"predecessor-version":[{"id":829,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/593\/revisions\/829"}],"wp:attachment":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=593"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=593"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=593"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}