{"id":3158,"date":"2025-08-17T10:11:19","date_gmt":"2025-08-17T02:11:19","guid":{"rendered":"https:\/\/www.leexinghai.com\/aic\/?p=3158"},"modified":"2025-08-17T10:41:42","modified_gmt":"2025-08-17T02:41:42","slug":"2-14%e5%a4%84%e7%90%86%e5%a4%9a%e7%b1%bb%e9%97%ae%e9%a2%98","status":"publish","type":"post","link":"https:\/\/www.leexinghai.com\/aic\/2-14%e5%a4%84%e7%90%86%e5%a4%9a%e7%b1%bb%e9%97%ae%e9%a2%98\/","title":{"rendered":"2.14\u5904\u7406\u591a\u7c7b\u95ee\u9898"},"content":{"rendered":"\n<p>SVM\u6709\u4e09\u79cd\u65b9\u5f0f\u5904\u7406\u591a\u7c7b\u95ee\u9898(\u7c7b\u522b>2)<\/p>\n\n\n\n<p>1.\u6539\u9020\u4f18\u5316\u7684\u76ee\u6807\u51fd\u6570\u548c\u9650\u5236\u6761\u4ef6\uff0c\u4f7f\u4e4b\u80fd\u5904\u7406\u591a\u7c7b<\/p>\n\n\n\n<p>2.\u4e00\u7c7bVS\u5176\u4ed6\u7c7b\uff08\u4e00\u7c7b\u5bf9K-1\u7c7b\uff09K\u4e3a\u7c7b\u6570 n\u4e2asvm<\/p>\n\n\n\n<p>3.\u4e00\u7c7bVS\u53e6\u4e00\u7c7b n*(n-1)\/2\u4e2asvm<\/p>\n\n\n\n<p>\u8bf4\u76f4\u63a5\u70b9\u5c31\u662f\u6253\u5206\u7cfb\u7edf\u3002<\/p>\n\n\n\n<p>\u6765\u770b\u8fd9\u4e2a\u4f8b\u5b50\uff1a<\/p>\n\n\n\n<p>SVM1: \u7c7b1 VS \u7c7b2\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-pale-pink-color\">0.5<\/mark>\u5206<\/p>\n\n\n\n<p>SVM2: \u7c7b1 VS \u7c7b3\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-red-color\">-0.2<\/mark>\u5206<\/p>\n\n\n\n<p>SVM1: \u7c7b2 VS \u7c7b3\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">0.4<\/mark>\u5206<\/p>\n\n\n\n<p>\u6253\u5206\u7ed3\u679c\uff1a<\/p>\n\n\n\n<p>\u7c7b1\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-pale-pink-color\">0.5<\/mark><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-red-color\">-0.2<\/mark>=0.3<\/p>\n\n\n\n<p>\u7c7b2\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-pale-pink-color\">-0.5<\/mark><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">+0.4<\/mark>=-0.1<\/p>\n\n\n\n<p>\u7c7b3\uff1a<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-red-color\">0.2<\/mark><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">-0.4<\/mark>=-0.2<\/p>\n\n\n\n<p>\u805a\u7c7b\u7b97\u6cd5\u7ed3\u5408\u51b3\u7b56\u6811\u7b97\u6cd5 \u4e8c\u5206\u7c7b\u5668->\u591a\u5206\u7c7b\u5668<\/p>\n\n\n\n<p>\u5904\u74068\u4e2a\u95ee\u9898\u6784\u5efa7\u4e2a\u5206\u7c7b\u5668\uff1a<\/p>\n\n\n\n<p>1 2 3 4    vs   5 6 7 8<\/p>\n\n\n\n<p>        \u2193               \u2193<\/p>\n\n\n\n<p>1 2 vs 3 4  | 5 6 vs 7 8<\/p>\n\n\n\n<p>   \u2193         \u2193     \u2193        \u2193<\/p>\n\n\n\n<p>1vs2 | 3vs4 | 5vs6 | 7vs8 <\/p>\n\n\n\n<p>\u4fdd\u8bc1\u6bcf\u4e2a\u5206\u7c7b\u5668\u533a\u5206\u7684\u4e24\u7c7b\u5dee\u522b\u663e\u8457<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u601d\u8003\uff1a\u5982\u679c\u652f\u6301\u5411\u91cf\u673a\u7684\u4e24\u7c7b\u8bad\u7ec3\u6837\u672c\u6570\u91cf\u4e0d\u5e73\u8861\uff0c\u5c06\u4f1a\u5bfc\u81f4\u4ec0\u4e48\u6837\u7684\u7ed3\u679c\uff1f<\/h2>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u539f\u59cb\u8f6f\u95f4\u9694 SVM \u76ee\u6807\u51fd\u6570<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"876\" height=\"114\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-43.png\" alt=\"\" class=\"wp-image-3159\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-43.png 876w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-43-300x39.png 300w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-43-768x100.png 768w\" sizes=\"auto, (max-width: 876px) 100vw, 876px\" \/><\/figure>\n\n\n\n<p>C \u5bf9\u6240\u6709\u677e\u5f1b\u53d8\u91cf \u03be<sub>i<\/sub>\u91c7\u7528\u540c\u4e00\u6743\u91cd\u3002<\/p>\n\n\n\n<p>\u82e5\u6b63\u8d1f\u6837\u672c\u6570\u91cf\u6781\u5ea6\u5931\u8861\uff08\u8bbe\u6b63\u7c7b N<sub>+<\/sub>\u226bN<sub>\u2212<\/sub>\u200b\uff09\uff0c\u5219\u60e9\u7f5a\u9879\u53d8\u4e3a <\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"616\" height=\"95\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-44.png\" alt=\"\" class=\"wp-image-3160\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-44.png 616w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-44-300x46.png 300w\" sizes=\"auto, (max-width: 616px) 100vw, 616px\" \/><\/figure>\n\n\n\n<p>\u4f18\u5316\u5668\u66f4\u5173\u5fc3\u591a\u6570\u7c7b\uff08\u6b63\u7c7b\uff09\u7684\u8bef\u5dee\uff0c\u56e0\u4e3a\u5b83\u4eec\u6570\u76ee\u591a\u3001\u603b\u60e9\u7f5a\u5927\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5bf9\u5076\u5f62\u5f0f\u9a8c\u8bc1<\/h4>\n\n\n\n<p>\u5bf9\u5076\u95ee\u9898\uff08L1 \u635f\u5931\uff09\uff1a <\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"948\" height=\"97\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-45.png\" alt=\"\" class=\"wp-image-3161\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-45.png 948w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-45-300x31.png 300w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-45-768x79.png 768w\" sizes=\"auto, (max-width: 948px) 100vw, 948px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9700\u8981 \u2211<sub>i<\/sub>\u03b1<sub>i<\/sub>y<sub>i<\/sub>=0\uff08\u6b63\u8d1f \u03b1 \u603b\u548c\u62b5\u6d88\uff09\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u6b63\u7c7b\u6837\u672c\u592a\u591a\uff0c\u4e3a\u6ee1\u8db3\u5e73\u8861\uff0c\u6b63\u7c7b \u03b1<sub>i<\/sub>\u200b \u5f80\u5f80\u88ab\u538b\u5f97\u5f88\u5c0f\uff1b\u5c11\u6570\u7c7b \u03b1<sub>i<\/sub>\u5fc5\u987b\u8f83\u5927\u624d\u80fd\u62b5\u6d88\u3002\u8fd9\u4f1a\u628a\u51b3\u7b56\u8d85\u5e73\u9762\u63a8\u5411\u5c11\u6570\u7c7b\u4e00\u4fa7\uff0c\u5bfc\u81f4\u5c11\u6570\u7c7b\u66f4\u5bb9\u6613\u88ab\u8bef\u5206\u7c7b\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u5178\u578b\u73b0\u8c61<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6307\u6807 \/ \u73b0\u8c61<\/th><th>\u6570\u5b66\u539f\u56e0<\/th><th>\u7ed3\u679c\u8868\u73b0<\/th><\/tr><\/thead><tbody><tr><td>\u603b\u4f53\u51c6\u786e\u7387\u9ad8<\/td><td>\u591a\u6570\u7c7b\u4e3b\u5bfc\u635f\u5931<\/td><td>\u770b\u4f3c\u6548\u679c\u4e0d\u9519<\/td><\/tr><tr><td>\u5c11\u6570\u7c7b\u53ec\u56de\u4f4e<\/td><td>\u5c11\u6570\u7c7b\u8bef\u5206\u60e9\u7f5a\u5c0f<\/td><td>\u5c11\u6570\u7c7b\u7ecf\u5e38\u88ab\u9519\u5206<\/td><\/tr><tr><td>\u652f\u6301\u5411\u91cf\u5206\u5e03<\/td><td>\u5c11\u6570\u7c7b \u03b1 \u5927\u3001\u6b63\u7c7b \u03b1 \u5c0f<\/td><td>\u652f\u6301\u5411\u91cf\u6570\u91cf\u5931\u8861<\/td><\/tr><tr><td>\u51b3\u7b56\u9762\u504f\u79fb<\/td><td>\u76ee\u6807\u51fd\u6570\u66f4\u201c\u5173\u5fc3\u201d\u591a\u6570\u7c7b<\/td><td>\u95f4\u9694\u9760\u8fd1\u5c11\u6570\u7c7b<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">4. \u89e3\u51b3\u601d\u8def<\/h4>\n\n\n\n<p>\uff081\uff09<strong>\u7c7b\u522b\u52a0\u6743 C<sub>i<\/sub><\/strong>.\u200b <\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"503\" height=\"128\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-46.png\" alt=\"\" class=\"wp-image-3162\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-46.png 503w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-46-300x76.png 300w\" sizes=\"auto, (max-width: 503px) 100vw, 503px\" \/><\/figure>\n\n\n\n<p>\u4f7f\u6bcf\u7c7b\u6837\u672c\u7684\u603b\u60e9\u7f5a\u76f8\u8fd1\uff0c\u5e38\u7528\u505a\u6cd5\uff1a<code>class_weight='balanced'<\/code>\u3002<\/p>\n\n\n\n<p>\uff082\uff09<strong>\u91cd\u91c7\u6837<\/strong><br>\u5bf9\u5c11\u6570\u7c7b\u8fdb\u884c\u8fc7\u91c7\u6837\uff08\u5982 SMOTE\uff09\u6216\u5bf9\u591a\u6570\u7c7b\u4e0b\u91c7\u6837\u3002<\/p>\n\n\n\n<p>\uff083\uff09<strong>\u6210\u672c\u654f\u611f SVM<\/strong><br>\u5728\u76ee\u6807\u51fd\u6570\u663e\u5f0f\u5199\u6210 \u2211<sub>i<\/sub>C<sub>i<\/sub>\u03be<sub>i<\/sub>\uff0c\u624b\u52a8\u8bbe\u5b9a\u91cd\u8981\u5ea6\u3002<\/p>\n\n\n\n<p>\uff084\uff09<strong>\u9608\u503c\u540e\u79fb<\/strong><br>\u8bad\u7ec3\u6a21\u578b\u4fdd\u6301\u539f\u6837\uff0c\u9884\u6d4b\u65f6\u4f7f\u7528 sign\u2061(f(x)\u2212\u03c4) \u8c03\u6574\u51b3\u7b56\u9608\u503c\u3002<\/p>\n\n\n\n<p>\uff085\uff09<strong>\u5f02\u5e38\u68c0\u6d4b\/\u4e00\u7c7b SVM<\/strong><br>\u5f53\u5c11\u6570\u7c7b\u6781\u5c11\u65f6\uff0c\u5c06\u5176\u89c6\u4e3a\u201c\u5f02\u5e38\u201d\u8fdb\u884c\u68c0\u6d4b\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>\u7ed3\u8bba<\/strong><br>\u6837\u672c\u6570\u91cf\u4e0d\u5e73\u8861\u4f1a\u4f7f\u652f\u6301\u5411\u91cf\u673a\u4e3b\u8981\u5173\u6ce8\u591a\u6570\u7c7b\u8bef\u5dee\uff0c\u51b3\u7b56\u8fb9\u754c\u5411\u5c11\u6570\u7c7b\u4e00\u4fa7\u504f\u79fb\uff0c\u4ece\u800c\u964d\u4f4e\u5c11\u6570\u7c7b\u7684\u8bc6\u522b\u7387\u3002\u901a\u8fc7\u7c7b\u522b\u52a0\u6743\u3001\u6570\u636e\u91cd\u91c7\u6837\u6216\u6210\u672c\u654f\u611f\u5b66\u4e60\u7b49\u65b9\u6cd5\u53ef\u6709\u6548\u7f13\u89e3\u8fd9\u4e00\u95ee\u9898\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u90a3\u4e48\u5982\u4f55\u6539\u9020\u652f\u6301\u5411\u91cf\u673a\u7684\u4f18\u5316\u51fd\u6570\u6765\u7f13\u89e3\u524d\u9762\u8fd9\u4e2a\u95ee\u9898\u6240\u5e26\u6765\u7684\u8d1f\u9762\u5f71\u54cd\uff1f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u628a\u201c\u6837\u672c\u4e0d\u5e73\u8861\u201d\u5199\u8fdb SVM \u76ee\u6807\u51fd\u6570\u7684\u4e09\u79cd\u7ecf\u5178\u6539\u9020<\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u4e0b\u9762\u7528\u6700\u5e38\u89c1\u7684 <strong>L1 \u8f6f\u95f4\u9694<\/strong> \u4e3a\u4f8b\uff0c\u82e5\u7528 L2 \u8f6f\u95f4\u9694\u6216 \u03bd-SVM\u3001Twin-SVM\uff0c\u601d\u8def\u5b8c\u5168\u7c7b\u4f3c\uff0c\u53ea\u662f\u516c\u5f0f\u91cc\u628a \u2211\u03be<sub>i\u200b<\/sub> \u6362\u6210 \u2211\u03be<sub>i<\/sub><sup>2<\/sup> \u6216\u8005\u591a\u4e00\u6761\u8d85\u5e73\u9762\u800c\u5df2\u3002<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">1\ufe0f\u20e3 \u7c7b\u522b\u52a0\u6743 C<sub>+<\/sub>C_\uff08\u6700\u5e38\u7528\uff09<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">\u6539\u9020\u540e\u7684\u539f\u59cb\u95ee\u9898<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"558\" height=\"165\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-47.png\" alt=\"\" class=\"wp-image-3163\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-47.png 558w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-47-300x89.png 300w\" sizes=\"auto, (max-width: 558px) 100vw, 558px\" \/><\/figure>\n\n\n\n<p>\u4e00\u822c\u8bbe<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"542\" height=\"107\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-48.png\" alt=\"\" class=\"wp-image-3164\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-48.png 542w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-48-300x59.png 300w\" sizes=\"auto, (max-width: 542px) 100vw, 542px\" \/><\/figure>\n\n\n\n<p>\u4f7f\u4e24\u7c7b\u8bef\u5dee\u5bf9\u76ee\u6807\u51fd\u6570\u7684<em>\u603b<\/em>\u8d21\u732e\u76f8\u5f53\u3002<\/p>\n\n\n\n<p><strong>\u5bf9\u5076\u5f62\u5f0f<\/strong> 0\u2264\u03b1<sub>i<\/sub>\u2264C<sub>+<\/sub>\u00a0\u6216\u00a0C<sub>\u2212<\/sub>\u2014\u2014\u4e0a\u754c\u56e0\u7c7b\u522b\u4e0d\u540c\u800c\u4e0d\u540c\uff0c\u5c11\u6570\u7c7b \u03b1 \u53ef\u4ee5\u53d6\u5230\u66f4\u5927\u7684\u503c\uff0c\u8fdb\u800c\u63a8\u56de\u66f4\u5408\u7406\u7684\u8d85\u5e73\u9762\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>\u5de5\u7a0b\u843d\u5730<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>libsvm\uff1a<code>-w1 \u03c11 -w-1 \u03c1-1<\/code><\/li>\n\n\n\n<li>scikit-learn\uff1a<code>class_weight='balanced'<\/code> \u6216\u4f20 dict <code>{1:w1,-1:w-1}<\/code><\/li>\n<\/ul>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2\ufe0f\u20e3 \u6837\u672c\u7ea7\u6743\u91cd \u03c9\u200b\uff08Cost-Sensitive \/ Fuzzy SVM\uff09<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">\u6539\u9020\u540e\u7684\u539f\u59cb\u95ee\u9898<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"408\" height=\"126\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-49.png\" alt=\"\" class=\"wp-image-3165\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-49.png 408w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-49-300x93.png 300w\" sizes=\"auto, (max-width: 408px) 100vw, 408px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u03c9<sub>i\u200b <\/sub>\u53ef\u4ee5\n<ul class=\"wp-block-list\">\n<li>\u53d6 N\/2Ny<sub>i<\/sub>\uff08\u9000\u5316\u56de\u7c7b\u522b\u6743\u91cd\uff09\uff1b<\/li>\n\n\n\n<li>\u6839\u636e\u6837\u672c\u7f6e\u4fe1\u5ea6 \/ \u566a\u58f0\u6253\u5206\uff08Fuzzy SVM\uff09\uff1b<\/li>\n\n\n\n<li>\u624b\u5de5\u6307\u5b9a\u8bef\u5206\u6210\u672c\uff08Cost-Sensitive SVM\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u5bf9\u5076\uff1a 0\u2264\u03b1<sub>i<\/sub>\u2264C<sub>\u03c9i<\/sub><\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>\u597d\u5904<\/strong>\uff1a\u7c92\u5ea6\u66f4\u7ec6\uff0c\u53ef\u5bf9<em>\u4e2a\u522b<\/em>\u5173\u952e\u6837\u672c\u653e\u5927\u6743\u91cd\u3002<br><strong>\u98ce\u9669<\/strong>\uff1a\u6743\u91cd\u6781\u7aef\u65f6\uff0c\u4f1a\u5bfc\u81f4\u6570\u503c\u4e0d\u7a33\u5b9a\uff0c\u9700\u8c03\u53c2\u6216\u5f52\u4e00\u5316\u3002<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3\ufe0f\u20e3 \u8c03\u6574\u95f4\u9694\u9608\u503c\uff08\u4e0d\u540c\u7c7b\u522b\u7684 margin\uff09<\/h3>\n\n\n\n<p>\u6709\u65f6\u5e0c\u671b <strong>\u6b63\u7c7b >1<\/strong>\u3001\u8d1f\u7c7b >1 \u7684\u89c4\u5b9a\u4e0d\u4e00\u6837\uff0c\u4f8b\u5982\u4ee4\u5c11\u6570\u7c7b margin \u66f4\u5927\uff1a <\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"612\" height=\"117\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-50.png\" alt=\"\" class=\"wp-image-3166\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-50.png 612w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-50-300x57.png 300w\" sizes=\"auto, (max-width: 612px) 100vw, 612px\" \/><\/figure>\n\n\n\n<p>\u914d\u5408\u7c7b\u522b\u6743\u91cd\uff0c\u8fd9\u5c31\u662f <strong>Margin-Rescaling SVM<\/strong>\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"810\" height=\"117\" src=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-51.png\" alt=\"\" class=\"wp-image-3167\" srcset=\"https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-51.png 810w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-51-300x43.png 300w, https:\/\/www.leexinghai.com\/aic\/wp-content\/uploads\/2025\/08\/image-51-768x111.png 768w\" sizes=\"auto, (max-width: 810px) 100vw, 810px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u53d6 m<sub>+<\/sub>>m<sub>\u2212<\/sub>\u200b \u53ef\u5f3a\u8feb\u6a21\u578b\u201c\u8fdc\u79bb\u201d\u5c11\u6570\u7c7b\uff0c\u63d0\u9ad8\u5176\u8bc6\u522b\u7387\u3002<\/li>\n\n\n\n<li>\u5bf9\u5076\u7ea6\u675f\u4ecd\u662f 0\u2264\u03b1<sub>i<\/sub>\u2264C\uff0c\u4f46 KKT \u4e2d\u51fa\u73b0 m<sub>yi\u200b\u200b<\/sub> \u2014\u2014\u6700\u7ec8\u7b49\u4ef7\u4e8e\u91cd\u65b0\u5e73\u79fb\u9608\u503c\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u8fd9\u4e9b\u6539\u9020\u5982\u4f55\u7f13\u89e3\u95ee\u9898\uff1f<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6539\u9020<\/th><th>\u4f18\u5316\u76ee\u6807\u4e2d\u53d1\u751f\u4e86\u4ec0\u4e48<\/th><th>\u76f4\u63a5\u6548\u679c<\/th><\/tr><\/thead><tbody><tr><td><strong>\u7c7b\u522b\u52a0\u6743 C<sub>\u00b1<\/sub><\/strong><\/td><td>\u591a\u6570\u7c7b\u6bcf\u9519 1 \u4e2a\u53ea\u7f5a C<sub>+<\/sub>\uff0c\u5c11\u6570\u7c7b\u7f5a C<sub>\u2212<\/sub>\u226bC<sub>+<\/sub>\u200b<\/td><td>\u51b3\u7b56\u9762\u8fdc\u79bb\u5c11\u6570\u7c7b\uff0c\u53ec\u56de\u2191<\/td><\/tr><tr><td><strong>\u6837\u672c\u6743\u91cd \u03c9<\/strong><\/td><td>\u60e9\u7f5a\u9879\u7cbe\u786e\u5230\u6837\u672c<\/td><td>\u53ef\u9488\u5bf9\u5c40\u90e8\u7a00\u758f\u533a\u3001\u6781\u7aef\u6837\u672c\u52a0\u5f3a\u5f71\u54cd<\/td><\/tr><tr><td><strong>margin \u91cd\u7f29\u653e<\/strong><\/td><td>\u5c11\u6570\u7c7b\u8981\u6c42\u66f4\u5927\u95f4\u9694<\/td><td>\u5bf9\u504f\u79fb\u7279\u522b\u654f\u611f\u7684\u6570\u636e\u96c6\u66f4\u6709\u6548<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u53c2\u8003\u4ee3\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>from sklearn.svm import SVC\n# \u65b9\u6cd51\uff1a\u7c7b\u522b\u52a0\u6743\nmodel = SVC(kernel='rbf', class_weight='balanced', C=1.0)\n\n# \u65b9\u6cd52\uff1a\u81ea\u5b9a\u4e49\u6837\u672c\u6743\u91cd\nsample_weights = np.where(y==1, N\/(2*N_pos), N\/(2*N_neg))\nmodel = SVC(kernel='rbf', C=1.0)\nmodel.fit(X, y, sample_weight=sample_weights)\n\n# \u65b9\u6cd53\uff1a\u81ea\u5b9a\u4e49 margin\uff08\u9700\u6539\u6e90\u7801\u6216\u7528 PyTorch \u81ea\u5199 loss\uff09\n<\/code><\/pre>\n\n\n\n<p>\u7ed3\u8bba\uff1a\u6837\u672c\u6570\u91cf\u4e0d\u5e73\u8861\u4f1a\u5bfc\u81f4\u652f\u6301\u5411\u91cf\u673a\u7684\u4e3b\u8981\u5173\u6ce8\u591a\u6570\u7c7b\u8bef\u5dee\uff0c\u51b3\u7b56\u8fb9\u754c\u5411\u5c11\u6570\u7c7b\u4e00\u4fa7\u504f\u79fb\u3002\u4ece\u800c\u964d\u4f4e\u5c11\u6570\u7c7b\u7684\u8bc6\u522b\u7387\u3002\u901a\u8fc7\u7c7b\u522b\u52a0\u6743\u3001\u6570\u636e\u91cd\u91c7\u6837\u6216\u6210\u672c\u654f\u611f\u5b66\u4e60\u7b49\u65b9\u6cd5\u89e3\u51b3\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>SVM\u6709\u4e09\u79cd\u65b9\u5f0f\u5904\u7406\u591a\u7c7b\u95ee\u9898(\u7c7b\u522b>2) 1.\u6539\u9020\u4f18\u5316\u7684\u76ee\u6807\u51fd\u6570\u548c\u9650\u5236\u6761\u4ef6\uff0c\u4f7f\u4e4b\u80fd\u5904\u7406\u591a\u7c7b 2.\u4e00\u7c7bVS\u5176\u4ed6\u7c7b [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3045,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[63],"tags":[],"class_list":["post-3158","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mlsh"],"_links":{"self":[{"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/posts\/3158","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/comments?post=3158"}],"version-history":[{"count":5,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/posts\/3158\/revisions"}],"predecessor-version":[{"id":3183,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/posts\/3158\/revisions\/3183"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/media\/3045"}],"wp:attachment":[{"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/media?parent=3158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/categories?post=3158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.leexinghai.com\/aic\/wp-json\/wp\/v2\/tags?post=3158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}