{"id":24,"date":"2024-09-10T07:24:14","date_gmt":"2024-09-09T23:24:14","guid":{"rendered":"http:\/\/chaixiangyu.cn\/?p=24"},"modified":"2024-09-11T21:40:51","modified_gmt":"2024-09-11T13:40:51","slug":"armadillo%e4%bd%bf%e7%94%a8%e4%bb%8b%e7%bb%8d%ef%bc%88%e5%85%ad%ef%bc%89%ef%bc%9afind%e3%80%81clamp%e3%80%81-replace","status":"publish","type":"post","link":"https:\/\/chaixiangyu.cn\/?p=24","title":{"rendered":"Armadillo\u4f7f\u7528\u4ecb\u7ecd\uff08\u516d\uff09\uff1afind\u3001clamp\u3001.replace"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">find<\/h1>\n\n\n\n<p>\u7528\u9014\uff1a<em>find\u51fd\u6570\u7528\u4e8e\u5bfb\u627e\u975e\u96f6\u5143\u7d20\u6216\u8005\u6ee1\u8db3\u6761\u4ef6\u7684\u5143\u7d20\u7684\u7d22\u5f15\u3002<\/em><br>\u8be5\u51fd\u6570\u91cd\u8f7d\u6709find( X )\u3001find( X, k )\u3001find( X, k, s )\u3002<br>\u7c7b\u578b\uff1a<em>\u666e\u901a\u51fd\u6570<\/em><br>1\u3001\u8fd4\u56de\u5305\u542b\u975e\u96f6\u6216\u6ee1\u8db3\u5173\u7cfb\u6761\u4ef6\u7684X\u5143\u7d20\u7684\u7d22\u5f15\u7684\u5217\u5411\u91cf<\/p>\n\n\n\n<p>2\u3001\u8f93\u51fa\u5411\u91cf\u5fc5\u987b\u5177\u6709uvec \u7c7b\u578b\uff08\u5373\u7d22\u5f15\u5b58\u50a8\u7c7b\u578b\u4e3a\u65e0\u7b26\u53f7\u6574\u6570uword)<\/p>\n\n\n\n<p>3\u3001X\u53ef\u7406\u89e3\u4e3a\u5411\u91cf\uff0c\u6309\u5217\u5bf9 X \u5143\u7d20\u8fdb\u884c\u6392\u5e8f<\/p>\n\n\n\n<p>4\u3001\u53ef\u4ee5\u7528\u5173\u7cfb\u8fd0\u7b97\u7b26\u4ee3\u66ffX\uff0c\u4f8b\u5982\u3002A &gt; 0.5<\/p>\n\n\n\n<p>5\u3001\u5982\u679ck=0\uff08\u9ed8\u8ba4\u503c\uff09\uff0c\u8fd4\u56de\u6240\u6709\u975e\u96f6\u5143\u7d20\u7684\u7d22\u5f15\uff0c\u5426\u5219\u6700\u591a\u8fd4\u56dek\u4e2a\u7d22\u5f15<\/p>\n\n\n\n<p>6\u3001\u5982\u679cs=&#8221;first&#8221;\uff08\u9ed8\u8ba4\uff09\uff0c\u6700\u591a\u8fd4\u56de\u975e\u96f6\u5143\u7d20\u7684\u7b2c\u4e00\u4e2a k\u4e2a\u7d22\u5f15<\/p>\n\n\n\n<p>7\u3001\u5982\u679cs=&#8221;last&#8221;\uff0c\u6700\u591a\u8fd4\u56de\u975e\u96f6\u5143\u7d20\u7684\u6700\u540e k \u4e2a\u7d22\u5f15<\/p>\n\n\n\n<p>\u6ce8\u610f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u83b7\u53d6\u95f4\u9694\u5185\u7684\u503c\uff0cclamp() \u6548\u7387\u66f4\u9ad8<\/li>\n\n\n\n<li>\u66ff\u6362\u7279\u5b9a\u503c\uff0c.replace()\u6548\u7387\u66f4\u9ad8<\/li>\n<\/ul>\n\n\n\n<p>\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mat  A  = randu&lt;mat&gt;(5,5);\nmat  B  = randu&lt;mat&gt;(5,5);\n\nuvec q1 = find(A &gt; B);\nuvec q2 = find(A &gt; 0.5);\nuvec q3 = find(A &gt; 0.5, 3, \"last\");\n\n\/\/ change elements of A greater than 0.5 to 1\nA.elem( find(A &gt; 0.5) ).ones();<\/code><\/pre>\n\n\n\n<h1 class=\"wp-block-heading\">clamp<\/h1>\n\n\n\n<p>\u7528\u9014\uff1a<em>clamp\u51fd\u6570\u7528\u4e8e\u83b7\u53d6\u9650\u5236\u5185\u7684\u5143\u7d20<\/em><br>\u7c7b\u578b\uff1a<em>\u666e\u901a\u51fd\u6570<\/em><br>clamp( X, min_val, max_val )<br>1\u3001\u521b\u5efa X\u7684\u526f\u672c\uff0c\u6bcf\u4e2a\u5143\u7d20\u4f4d\u4e8e[min_val\uff0cmax_val]\u4e4b\u95f4;<br>\u4efb\u4f55\u4f4e\u4e8emin_val\u7684\u5143\u7d20\u5c06\u8bbe\u7f6e\u4e3amin_val\uff0c\u9ad8\u4e8emax_val\u7684\u5143\u7d20\u5c06\u8bbe\u7f6e\u4e3amax_val\uff1b<br>2\u3001\u5982\u679cX\u662f\u7a00\u758f\u77e9\u9635\uff0c\u5219\u8be5\u64cd\u4f5c\u4ec5\u9002\u7528\u4e8e\u975e\u96f6\u5143\u7d20\u3002<\/p>\n\n\n\n<p>\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mat A = randu&lt;mat&gt;(5,5);\n\nmat B = clamp(A, 0.2,     0.8); \n\nmat C = clamp(A, A.min(), 0.8); \n\nmat D = clamp(A, 0.2, A.max()); <\/code><\/pre>\n\n\n\n<h1 class=\"wp-block-heading\">.replace<\/h1>\n\n\n\n<p>\u7528\u9014\uff1a<em>.replace\u51fd\u6570\u7528\u4e8e\u5c06\u65b0\u503c\u66ff\u6362\u7279\u6b8a\u5143\u7d20<\/em><br>\u7c7b\u578b\uff1a<em>\u6210\u5458\u51fd\u6570<\/em><\/p>\n\n\n\n<p>.replace( old_value, new_value )<br>1\u3001Mat \u3001Col \u3001Row\u3001Cube\u548c SpMat \u7684\u6210\u5458\u51fd\u6570\uff1b<\/p>\n\n\n\n<p>2\u3001\u6240\u6709\u7b49\u4e8eold_value\u7684\u5143\u7d20\uff0c\u5c06\u8bbe\u7f6e\u4e3anew_value\uff1b<\/p>\n\n\n\n<p>3\u3001\u5bb9\u5668\u548cold_valuenew_value\u5fc5\u987b\u5339\u914d\u5bb9\u5668\u5bf9\u8c61\u4f7f\u7528\u7684\u5143\u7d20\u7c7b\u578b\uff08\u4f8b\u5982\uff0c\u5bf9\u4e8emat\u7c7b\u578b\u4e3a\u53cc\u7cbe\u5ea6)\u3002<\/p>\n\n\n\n<p>\u8b66\u544a\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6d6e\u70b9\u6570\uff08float\u548cdouble\uff09\u662f\u8fd1\u4f3c\u503c\uff0c\u56e0\u4e3a\u5176\u7cbe\u5ea6\u5fc5\u7136\u6709\u9650<\/li>\n\n\n\n<li>\u5bf9\u4e8e\u7a00\u758f\u77e9\u9635 \uff08SpMat\uff09\uff0c\u5f53old_value=0\u4e0d\u9002\u7528<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>mat A(5,6,fill::randu);\n\nA.diag().fill(datum::nan);\n\nA.replace(datum::nan, 0);  \/\/ replace each NaN with 0<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>find \u7528\u9014\uff1afind\u51fd\u6570\u7528\u4e8e\u5bfb\u627e\u975e\u96f6\u5143\u7d20\u6216\u8005\u6ee1\u8db3\u6761\u4ef6\u7684\u5143\u7d20\u7684\u7d22\u5f15\u3002\u8be5\u51fd\u6570\u91cd\u8f7d\u6709find( X )\u3001find [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-24","post","type-post","status-publish","format-standard","hentry","category-algorithm"],"_links":{"self":[{"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/posts\/24","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=24"}],"version-history":[{"count":1,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions"}],"predecessor-version":[{"id":25,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions\/25"}],"wp:attachment":[{"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chaixiangyu.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}