{"id":767,"date":"2023-02-08T10:05:01","date_gmt":"2023-02-08T02:05:01","guid":{"rendered":"http:\/\/www.algmain.com\/?page_id=767"},"modified":"2023-02-13T10:10:59","modified_gmt":"2023-02-13T02:10:59","slug":"three-dimension","status":"publish","type":"page","link":"http:\/\/www.algmain.com\/index.php\/algorithm-article\/projective-variance-split\/three-dimension\/","title":{"rendered":"\u4e09\u7ef4\u6295\u5f71\u65b9\u5dee\u5206\u5272"},"content":{"rendered":"\n<p>\u5728\u8ba8\u8bba\u4e86\u4e8c\u7ef4\u65b9\u5dee\u5206\u5272\u4e4b\u540e\uff0c\u7ee7\u7eed\u8ba8\u8bba\u4e09\u7ef4\u65b9\u5dee\u5206\u5272\u7684\u95ee\u9898\uff1a\u5982\u4f55\u5728\u4e09\u7ef4\u7a7a\u95f4\u4e2d\u9009\u62e9\u4e00\u6761\u76f4\u7ebf\\(l\\)\uff0c\u4f7f\u5f97\u4e09\u7ef4\u70b9\u96c6\\(A=\\{(x_i,y_i,z_i)|i=1,2,&#8230;N\\}\\)\u7684\u6295\u5f71\u70b9\\(P=\\{ p_i\u2208l|i=1,2,&#8230;N\\}\\)\u7684\u8ddd\u79bb\u65b9\u5dee\u6700\u5927\u3002<\/p>\n\n\n\n<p>\u901a\u8fc7\u524d\u9762\u5f97\u8ba8\u8bba\u53ef\u77e5\uff1a\u53ef\u4ee5\u4e09\u4f4d\u70b9\u96c6\\(A\\)\u7684\u8d28\u5fc3\u4e3a\u539f\u70b9\uff0c\u5efa\u7acb\u4e09\u7ef4\u76f4\u89d2\u5750\u6807\u7cfb\u3002\u8bbe\u76f4\u7ebf\\(l\\)\u901a\u8fc7\u5750\u6807\u539f\u70b9\uff0c\u5176\u5355\u4f4d\u65b9\u5411\u77e2\u91cf\\(\\overrightarrow l = (a,b,c)\\)\u3002\u4ee4\uff1a<\/p>\n\n\n\n<p>\\[H = \\sum\\limits_{i = 1}^N {{{(\\overrightarrow {O{p_i}} \\cdot \\overrightarrow l )}^2}} = \\sum\\limits_{i = 1}^N {{{(a{x_i} + b{y_i} + c{z_i})}^2}} \\]<\/p>\n\n\n\n<p>\u663e\u7136\\(H\\)\u662f\u5173\u4e8e\\(a,b,c\\)\u7684\u591a\u5143\u51fd\u6570\uff0c\u9644\u52a0\u6761\u4ef6\u4e3a\uff1a<\/p>\n\n\n\n<p>\\[ \\phi (a,b,c) = {a^2} + {b^2} + {c^2} &#8211; 1 = 0 \\]<\/p>\n\n\n\n<p>\u5148\u505a\u62c9\u683c\u6717\u65e5\u51fd\u6570\uff1a<\/p>\n\n\n\n<p>\\[ L(a,b,c) = H(a,b,c) + \\lambda \\cdot \\phi (a,b,c) \\]<\/p>\n\n\n\n<p>\u5176\u4e2d\\(\\lambda\\)\u4e3a\u53c2\u6570\uff0c\u5206\u522b\u5bf9\u53c2\u6570\\(a,b,c\\)\u6c42\u4e00\u9636\u504f\u5bfc\u6570\uff0c\u5e76\u4f7f\u4e4b\u7b49\u4e8e0\u3002\u7136\u540e\u8054\u7acb\u65b9\u7a0b\u7ec4\uff1a<\/p>\n\n\n\n<p>\\[ \\frac{{\\partial L}}{{\\partial a}} = \\frac{{\\partial H}}{{\\partial a}} + \\lambda \\cdot \\frac{{\\partial \\phi }}{{\\partial a}} = \\sum\\limits_{i = 1}^N {2(a{x_i} + b{y_i} + c{z_i}){x_i} + 2\\lambda a = 0} \\]<\/p>\n\n\n\n<p>\\[ \\frac{{\\partial L}}{{\\partial b}} = \\frac{{\\partial H}}{{\\partial b}} + \\lambda \\cdot \\frac{{\\partial \\phi }}{{\\partial b}} = \\sum\\limits_{i = 1}^N {2(a{x_i} + b{y_i} + c{z_i}){y_i} + 2\\lambda b = 0} \\]<\/p>\n\n\n\n<p>\\[\\frac{{\\partial L}}{{\\partial c}} = \\frac{{\\partial H}}{{\\partial c}} + \\lambda \\cdot \\frac{{\\partial \\phi }}{{\\partial c}} = \\sum\\limits_{i = 1}^N {2(a{x_i} + b{y_i} + c{z_i}){z_i} + 2\\lambda c = 0} \\]<\/p>\n\n\n\n<p>\u4ee4\uff1a<\/p>\n\n\n\n<p>\\[\\begin{array}{*{20}{c}}<br>{{m_{xx}} = \\sum\\limits_{i = 1}^N {{x_i}{x_i}} }&amp;{{m_{xy}} = \\sum\\limits_{i = 1}^N {{x_i}{y_i}} }&amp;{{m_{xz}} = \\sum\\limits_{i = 1}^N {{x_i}{z_i}} }<br>\\end{array}\\]<\/p>\n\n\n\n<p>\\[\\begin{array}{*{20}{c}}<br>{{m_{yy}} = \\sum\\limits_{i = 1}^N {{y_i}{y_i}} }&amp;{{m_{yz}} = \\sum\\limits_{i = 1}^N {{y_i}{z_i}} }&amp;{{m_{zz}} = \\sum\\limits_{i = 1}^N {{z_i}{z_i}} }<br>\\end{array}\\]<\/p>\n\n\n\n<p>\u6700\u540e\u53ef\u4ee5\u7b80\u5316\u5f97\u5230\u4e00\u4e2a\u4e00\u5143\u4e09\u6b21\u65b9\u7a0b\uff08\u8be5\u65b9\u7a0b\u8017\u8d39\u4e86\u4f5c\u8005\u4e0d\u5c11\u624b\u5de5\u7b97\u529b\uff09\uff1a<\/p>\n\n\n\n<p>\\[ {\\lambda ^3} + ({m_{xx}} + {m_{yy}} + {m_{zz}}){\\lambda ^2} \\\\ + ({m_{xx}}{m_{yy}} + {m_{xx}}{m_{zz}} + {m_{yy}}{m_{zz}} &#8211; m_{xy}^2 &#8211; m_{xz}^2 &#8211; m_{yz}^2)\\lambda \\\\ + ({m_{xx}}{m_{yy}}{m_{zz}} &#8211; {m_{xx}}m_{yz}^2 &#8211; {m_{yy}}m_{xz}^2 &#8211; {m_{zz}}m_{xy}^2 + 2{m_{xy}}{m_{xz}}{m_{yz}}) = 0 \\]<\/p>\n\n\n\n<p>\u5230\u6b64\u65f6\u53ef\u4ee5\u5229\u7528Matlab\u7b49\u8f6f\u4ef6\u76f4\u63a5\u6c42\u5f97\\(\\lambda\\)\u6570\u503c\u89e3\u3002\u5e26\u5165\u4e0a\u8ff0\u65b9\u7a0b\uff0c\u5373\u53ef\u89e3\u5f00\\(a,b,c\\)\u7684\u6570\u503c\u3002\u90a3\u4e48\u76f4\u7ebf\\(l\\)\u6240\u4ee3\u8868\u7684\u65b9\u5411\u662f\u8ddd\u79bb\u65b9\u5dee\u6700\u5927\u503c\u65b9\u5411\uff0c\u4e5f\u662f\u5206\u5272\u5e73\u9762\u7684\u6cd5\u77e2\u65b9\u5411\uff0c\u4e14\u8be5\u5206\u5272\u5e73\u9762\u8fc7\u8d28\u5fc3\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u8ba8\u8bba\u4e86\u4e8c\u7ef4\u65b9\u5dee\u5206\u5272\u4e4b\u540e\uff0c\u7ee7\u7eed\u8ba8\u8bba\u4e09\u7ef4\u65b9\u5dee\u5206\u5272\u7684\u95ee\u9898\uff1a\u5982\u4f55\u5728\u4e09\u7ef4\u7a7a\u95f4\u4e2d\u9009\u62e9\u4e00\u6761\u76f4\u7ebf\uff0c\u4f7f\u5f97\u4e09\u7ef4\u70b9\u96c6\u7684\u6295\u5f71\u70b9\u7684\u8ddd\u79bb [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":591,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-767","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/pages\/767"}],"collection":[{"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/comments?post=767"}],"version-history":[{"count":22,"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/pages\/767\/revisions"}],"predecessor-version":[{"id":1515,"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/pages\/767\/revisions\/1515"}],"up":[{"embeddable":true,"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/pages\/591"}],"wp:attachment":[{"href":"http:\/\/www.algmain.com\/index.php\/wp-json\/wp\/v2\/media?parent=767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}