{"id":471,"date":"2018-09-03T07:08:01","date_gmt":"2018-09-02T22:08:01","guid":{"rendered":"https:\/\/best-biostatistics.com\/toukei-er\/entry\/what-is-pruning-of-decision-tree-learning\/"},"modified":"2024-10-12T23:10:08","modified_gmt":"2024-10-12T14:10:08","slug":"what-is-pruning-of-decision-tree-learning","status":"publish","type":"post","link":"https:\/\/best-biostatistics.com\/toukei-er\/entry\/what-is-pruning-of-decision-tree-learning\/","title":{"rendered":"\u6c7a\u5b9a\u6728\u306e\u904e\u5b66\u7fd2\u3092\u9632\u3050\u526a\u5b9a\uff08\u679d\u5208\u308a\uff09\u3068\u306f\uff1f"},"content":{"rendered":"\n

\u6c7a\u5b9a\u6728\u306b\u306f\u526a\u5b9a\uff08\u305b\u3093\u3066\u3044\uff09\u3068\u3044\u3046\u904e\u7a0b\u304c\u3042\u308b\u3002<\/p>\n\n\n\n

\u526a\u5b9a\u3068\u306f\u4f55\u304b\uff1f<\/p>\n\n\n\n

\u7c21\u5358\u306b\u7d39\u4ecb\u3002<\/p>\n\n\n\n\n\n\n\n

\u6c7a\u5b9a\u6728\u306e\u5f31\u70b9\u3000\u904e\u5b66\u7fd2<\/h2>\n\n\n\n

\u3042\u308b\u30c7\u30fc\u30bf\u30bb\u30c3\u30c8\u304b\u3089\u3001\u6c7a\u5b9a\u6728\u3092\u4f5c\u3063\u305f\u3068\u3059\u308b\u3002<\/p>\n\n\n\n

\u6c7a\u5b9a\u6728\u306f\u3001\u5927\u304d\u304f\u8302\u3089\u305b\u308c\u3070\u8302\u3089\u305b\u308b\u307b\u3069\u3001\u304d\u308c\u3044\u306b\u5206\u5c90\u3057\u3066\u3001\u5206\u985e\u3057\u3066\u304f\u308c\u308b\u3002<\/p>\n\n\n\n

\u3057\u304b\u3057\u306a\u304c\u3089\u3001\u6a5f\u68b0\u5b66\u7fd2\u306e\u89b3\u70b9\u304b\u3089\u8a00\u3046\u3068\u3001\u3042\u307e\u308a\u306b\u304d\u308c\u3044\u306b\u5206\u985e\u3057\u3066\u3057\u307e\u3046\u306e\u306f\u597d\u307e\u3057\u304f\u306a\u3044\u3002<\/p>\n\n\n\n

\u306a\u305c\u306a\u3089\u3001\u5b8c\u74a7\u306b\u30c7\u30fc\u30bf\u30bb\u30c3\u30c8\u3092\u5206\u985e\u3067\u304d\u3066\u3082\u3001\u307b\u304b\u306e\u30c7\u30fc\u30bf\u30bb\u30c3\u30c8\u3067\u8a66\u3057\u3066\u307f\u308b\u3068\u3001\u3046\u307e\u304f\u5206\u985e\u3067\u304d\u306a\u3044\u304b\u3089\u3002<\/p>\n\n\n\n

\u3053\u308c\u3092\u904e\u5b66\u7fd2 overfitting\u3068\u3044\u3046\u3002<\/p>\n\n\n\n

Overfitting\u3057\u305f\u6c7a\u5b9a\u6728\u306f\u3001\u6c4e\u7528\u6027\u304c\u306a\u304f\u5fdc\u7528\u304c\u5229\u304b\u306a\u3044\u3002<\/p>\n\n\n\n

\u6c7a\u5b9a\u6728\u306e\u904e\u5b66\u7fd2\u3092\u9632\u3050\u526a\u5b9a<\/h2>\n\n\n\n

\u6c4e\u7528\u6027\u3092\u6301\u305f\u305b\u3066\u3001\u4f7f\u3048\u308b\u6c7a\u5b9a\u6728\u306b\u3059\u308b\u305f\u3081\u306b\u3001\u300c\u526a\u5b9a pruning\u300d\u3092\u884c\u3046\u3002<\/p>\n\n\n\n

\u8907\u96d1\u3055\u3068\u3042\u3066\u306f\u307e\u308a\u3092\u72a0\u7272\u306b\u3057\u3066\u3001overfitting\u3092\u907f\u3051\u3001\u6c4e\u7528\u6027\u3092\u6301\u305f\u305b\u308b\u306e\u304c\u526a\u5b9a\u3002<\/p>\n\n\n\n

\u526a\u5b9a pruning \u306b\u306f\u3044\u304f\u3064\u304b\u3042\u308b\u304c\u3001\u4ee3\u8868\u7684\u306a\u3082\u306e\u304ccost-complexity pruning\u3002<\/p>\n\n\n\n

\u6c7a\u5b9a\u6728\u306f\u3001\u5927\u304d\u304f\u3066\u8907\u96d1\u3067\u3042\u308c\u3070\u3042\u308b\u307b\u3069\u3001\u8aa4\u5206\u985e\u3092\u306a\u304f\u3059\u3053\u3068\u304c\u3067\u304d\u308b\u3002<\/p>\n\n\n\n

\u3057\u304b\u3057\u3001\u5927\u304d\u304f\u3066\u8907\u96d1\u3059\u304e\u308b\u3068overfitting\u306e\u30ea\u30b9\u30af\u304c\u3042\u308b\u3002<\/p>\n\n\n\n

\u3053\u306e\u8907\u96d1\u6027\u306b\u7f70\u5247\u3092\u3064\u3051\u305f\u306e\u304c\u3001cost-complexity pruning\u3002<\/p>\n\n\n\n

\u03b1 \u3067\u8868\u3059complex parameter\u3092\u5c0e\u5165\u3059\u308b\u3002<\/p>\n\n\n\n

\u03b1 \u00d7 \u8449\u3063\u3071\uff08\u30ce\u30fc\u30c9\uff09\u306e\u6570\uff08\u6c7a\u5b9a\u6728\u306e\u30b5\u30a4\u30ba\uff09\u3092\u7f70\u5247\u306b\u3059\u308b\u3002<\/p>\n\n\n\n

\u03b1 \u306f\u3001\u300c\u526a\u5b9a\u3057\u305f\u6c7a\u5b9a\u6728\u306e\u8aa4\u5206\u985e\uff08\u5927\u304d\u304f\u306a\u308b\uff09\u3068\u526a\u5b9a\u3059\u308b\u524d\u306e\u6c7a\u5b9a\u6728\u306e\u8aa4\u5206\u985e\uff08\u5c0f\u3055\u3044\uff09\u306e\u5dee\u300d\u3068\u300c\u6c7a\u5b9a\u6728\u306e\u30b5\u30a4\u30ba – 1\u300d\u306e\u6bd4\u3002<\/p>\n\n\n\n

\u6c4e\u7528\u6027\u9ad8\u304f\u3001\u30b5\u30a4\u30ba\u306f\u6700\u5c0f\u9650\u306a\u3093\u3060\u3051\u3069\u3001\u8aa4\u5206\u985e\u3082\u6700\u5c0f\u9650\u306e\u3044\u3044\u3068\u3053\u308d\u3069\u308a\u306e\u6c7a\u5b9a\u6728\u3092\u4f5c\u308d\u3046\u3068\u3044\u3046\u767a\u60f3\u3002<\/p>\n\n\n\n

\uff1e\uff1e\u3082\u3046\u7d71\u8a08\u3067\u60a9\u3080\u306e\u306f\u7d42\u308f\u308a\u306b\u3057\u307e\u305b\u3093\u304b\uff1f\u00a0<\/a><\/strong><\/span><\/p>\r\n\"\"<\/a>\r\n

\u21911\u4e07\u4eba\u4ee5\u4e0a\u306e\u533b\u7642\u5f93\u4e8b\u8005\u304c\u8cfc\u8aad\u4e2d<\/span><\/strong><\/span><\/p><\/div>

\u307e\u3068\u3081<\/h2>\n\n\n\n

\u304d\u308c\u3044\u306b\u5206\u985e\u3067\u304d\u308b\u6c7a\u5b9a\u6728\u306foverfitting\u3068\u3044\u3046\u5f31\u70b9\u304c\u3042\u308b\u3002<\/p>\n\n\n\n

\u65b0\u3057\u3044\u30c7\u30fc\u30bf\u3067\u4e88\u6e2c\u3059\u308b\u6027\u80fd\u304c\u843d\u3061\u308b\u3002<\/p>\n\n\n\n

Overfitting\u3092\u907f\u3051\u308b\u305f\u3081\u306b\u526a\u5b9a pruning\u304c\u3042\u308b\u3002<\/p>\n\n\n\n

\u526a\u5b9a\u3092\u3059\u308b\u3053\u3068\u3067\u6c4e\u7528\u6027\u304c\u3042\u308b\u300c\u4f7f\u3048\u308b\u300d\u6c7a\u5b9a\u6728\u304c\u4f5c\u308c\u308b\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u6c7a\u5b9a\u6728\u306b\u306f\u526a\u5b9a\uff08\u305b\u3093\u3066\u3044\uff09\u3068\u3044\u3046\u904e\u7a0b\u304c\u3042\u308b\u3002 \u526a\u5b9a\u3068\u306f\u4f55\u304b\uff1f \u7c21\u5358\u306b\u7d39\u4ecb\u3002<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[25,103],"tags":[],"class_list":["post-471","post","type-post","status-publish","format-standard","hentry","category-25","category-103"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/posts\/471","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/comments?post=471"}],"version-history":[{"count":2,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/posts\/471\/revisions"}],"predecessor-version":[{"id":2758,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/posts\/471\/revisions\/2758"}],"wp:attachment":[{"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/media?parent=471"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/categories?post=471"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/best-biostatistics.com\/toukei-er\/wp-json\/wp\/v2\/tags?post=471"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}