{"id":406,"date":"2018-08-20T15:40:36","date_gmt":"2018-08-20T06:40:36","guid":{"rendered":"http:\/\/jazzman.pe.kr\/blog\/?p=406"},"modified":"2026-02-14T12:39:29","modified_gmt":"2026-02-14T03:39:29","slug":"r-selecting-rows-with-na","status":"publish","type":"post","link":"https:\/\/jazzman.pe.kr\/blog\/index.php\/2018\/08\/20\/406\/","title":{"rendered":"[R] selecting rows with NA"},"content":{"rendered":"\n<p>R \uc740 \ud1b5\uacc4 \ubd84\uc57c\uc5d0\uc11c (\ud2b9\ud788 data science \ucabd) \ub300\uc138\ub77c\uace0 \ud560 \uc218 \uc788\uc9c0\uc694. \uba87\ub144 \uc804\ubd80\ud130 R\uc744 \uc775\ud600 \ub370\uc774\ud130 \ubd84\uc11d\uc5d0 \uc774\uc6a9\ud558\uace0 \uc788\ub294\ub370, \ub9ce\uc740 \uc7a5\uc810\uc774 \uc788\uc73c\ub098 \uac00\ub054 \uc804\ud600 \uc9c1\uad00\uc801\uc774\uc9c0 \uc54a\ub294 \uacb0\uacfc\ub97c \ub0b4\ub358\uc9c0\ub294 \uacbd\uc6b0\uac00 \uc788\uc5b4 \uba58\ubd95\ud588\ub358 \uc801\uc774 \uc5ec\ub7ec\ubc88 \uc788\uc5c8\uc2b5\ub2c8\ub2e4. \uadf8 \uc9c1\uad00\uc774\ub780 \uac83\uc774 \uc9c0\uadf9\ud788 \uc778\uac04\uc801\uc778 \uac83\uc774\uace0 \uc0ac\uc2e4\uc740 R \uc774\ub77c\ub294 \ud504\ub85c\uadf8\ub798\ubc0d \uc5b8\uc5b4\ub97c \uc81c\ub300\ub85c \uc774\ud574 \ubabb\ud55c \ub54c\ubb38\uc5d0 \uc0dd\uae30\ub294 \uc77c\ub4e4\uc774\uc9c0\ub9cc, SAS\ub098 Stata \uc640 \uac19\uc740 \ud1b5\uacc4 \ud328\ud0a4\uc9c0\ub4e4\uc744 \ub2e4\ub8e8\uba74\uc11c\ub294 \uacaa\uc9c0 \uc54a\uc558\ub358 \uad34\uc0c1\ud55c \uc624\ub958\uc5d0 \uc2dc\ub2ec\ub9ac\ub294 \uac83\uc774 \uc369 \uae30\ubd84 \uc88b\uc9c0\ub294 \uc54a\uc740 \uc77c\uc774\uc9c0\uc694. \uadf8 \uc911 \ub300\ud45c\uc801\uc778 \uac83 \uc911 \ud558\ub098\uac00 NA \uad00\ub828\uc785\ub2c8\ub2e4. missing data \ub97c R \uc774 \ub2e4\ub8e8\ub294 \ubc29\ubc95\uc774 \ubb34\ucc99 \uc5c4\uaca9\ud558\ub2ec\uae4c\uc694, \uc774\uac78 \uc774\ud574 \ubabb\ud558\uba74 \uc815\ub9d0 \uad34\uc774\ud55c \uc5d0\ub7ec\uc5d0 \uba38\ub9ac\ub97c \uc950\uc5b4 \ub72f\uac8c \ub429\ub2c8\ub2e4. <\/p>\n\n\n\n<p>\ub2e4\uc74c\uacfc \uac19\uc740 \uc608\ub97c \ubcf4\uc2dc\uc9c0\uc694. x2 \uceec\ub7fc\uc5d0 NA \uac00 \ubc15\ud600 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>> df &lt;- data.frame(no = 1:5, x1 = c(1, 0, 0, 1, 1), x2 = c(0, NA, NA, 1, 0))\n> df\n  no x1 x2\n1  1  1  0\n2  2  0 NA\n3  3  0 NA\n4  4  1  1\n5  5  1  0\n> df&#91;df$x1 == 1, &#93;\n  no x1 x2\n1  1  1  0\n4  4  1  1\n5  5  1  0\n> df&#91;df$x1 != 1, &#93;\n  no x1 x2\n2  2  0 NA\n3  3  0 NA\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">&lt;-<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">data<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">frame<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">:<\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">c<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">c<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">df$x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">df$x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\uc790, \uc5ec\uae30\uae4c\uc9c4 \uba40\uca61\ud558\uc8e0. \uadf8\ub7f0\ub370 x2 \uc5d0 \uc870\uac74\uc744 \uc918\uc11c \uc120\ud0dd\uc744 \ud558\ub294 \uc21c\uac04 \uad34\uc0c1\ub9dd\uce59\ud55c \ud604\uc0c1\uc774 \ubc8c\uc5b4\uc9d1\ub2c8\ub2e4.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>> df&#91;df$x2 == 1, &#93;\n     no x1 x2\nNA   NA NA NA\nNA.1 NA NA NA\n4     4  1  1\n> df&#91;df$x2 != 1, &#93;\n     no x1 x2\n1     1  1  0\nNA   NA NA NA\nNA.1 NA NA NA\n5     5  1  0\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">     <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\">   <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">     <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">     <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">     <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\">   <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">     <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\uc774\uac74 \ub2f9\uc5f0\ud788 \ubc14\ub77c\ub358 \ubc14\uac00 \uc544\ub2c8\uc5c8\uaca0\uc9c0\uc694? \uadf8\ub0e5 x2 \uac00 1\uc77c \ub54c, \ub610\ub294 1\uc774 \uc544\ub2d0 \ub54c\ub97c \uace8\ub77c\uc8fc\uba74 \ub420 \uac78, \uc65c \uc774\ub7f0 \uc5b4\uc774\uc5c6\ub294 \uc77c\uc774 \ubc8c\uc5b4\uc9c8\uae4c\uc694?<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>> df$x2 == 1\n&#91;1&#93; false    NA    NA  true false\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">&#93; <\/span><span style=\"color: #81A1C1\">false<\/span><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #D8DEE9\">NA<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #81A1C1\">true<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">false<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\uc774\uac78 \ubcf4\uc2dc\uba74 \uc774\ud574\uac00 \ub418\uaca0\uc8e0. NA \ub294 \uac19\uc740 \uc9c0 \ub2e4\ub978\uc9c0 \ube44\uad50\uac00 \uc548\ub429\ub2c8\ub2e4. \ube44\uad50\ub97c \ud558\ub824\uace0 \ud558\uba74 \uacb0\uacfc\ub294 \uadf8\ub0e5 NA. \uadf8\ub798\uc11c \ud589 \uc804\uccb4\uac00 NA \uac00 \ub418\ubc84\ub9ac\ub294 \ucc38\uc0ac\uac00 \ubc8c\uc5b4\uc9c0\uc8e0.<br>\n\uc774\ub7f0 \uc77c\uc774 \uc548 \ubc8c\uc5b4\uc9c0\ub824\uba74? \uc774\ub7f0 \ubc29\ubc95\ub4e4\uc774 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>> df&#91;which(df$x2 == 1), &#93;\n  no x1 x2\n4  4  1  1\n> df&#91;which(df$x2 != 1), &#93;\n  no x1 x2\n1  1  1  0\n5  5  1  0\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #88C0D0\">which<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #88C0D0\">which<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\ub9cc\uc57d &#8216;x2 \uac00 1 \uc774 \uc544\ub2cc \uacbd\uc6b0&#8217;\uc5d0 NA \ub97c \ud3ec\ud568\uc2dc\ucf1c \uc8fc\uace0 \uc2f6\ub2e4\uba74, \ubc88\uac70\ub86d\uc9c0\ub9cc \ub2e4\uc74c\uacfc \uac19\uc774 \ud574\uc57c \ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>> df&#91;df$x2 != 1 | is.na(df$x2), &#93;\n  no x1 x2\n1  1  1  0\n2  2  0 NA\n3  3  0 NA\n5  5  1  0\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">|<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">is<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">na<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df$x2<\/span><span style=\"color: #D8DEE9FF\">)<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> &#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\ucf54\ub4dc\uac00 \ubb34\ucc99 \uc9c0\uc800\ubd84\ud574 \ubcf4\uc774\ub294\ub370&#8230; \ub2e4\ub978 \ud574\uacb0 \ubc29\ubc95\uc740? \ubb3c\ub860 \uc788\uc8e0. \uadf8\uac83\ub3c4 \uc544\uc8fc \ub9ce\uc774&#8230; R \uc778\ub370!<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:clamp(14px, .875rem, 21px);font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:clamp(20px, 1.25rem, 30px);--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><pre class=\"code-block-pro-copy-button-pre\" aria-hidden=\"true\"><textarea class=\"code-block-pro-copy-button-textarea\" tabindex=\"-1\" aria-hidden=\"true\" readonly>## subset \ud568\uc218 \uc774\uc6a9\n> subset(df, x2 == 1)\n  no x1 x2\n4  4  1  1\n> subset(df, x2 != 1)\n  no x1 x2\n1  1  1  0\n5  5  1  0\n> subset(df, x2 != 1 | is.na(x2))\n  no x1 x2\n1  1  1  0\n2  2  0 NA\n3  3  0 NA\n5  5  1  0\n\n## dplyr filter \uc774\uc6a9\n> library(dplyr)\n> df %>% filter(x2 == 1)\n  no x1 x2\n1  4  1  1\n> df %>% filter(x2 != 1)\n  no x1 x2\n1  1  1  0\n2  5  1  0\n \n> df %>% filter(x2 != 1 | is.na(x2))\n  no x1 x2\n1  1  1  0\n2  2  0 NA\n3  3  0 NA\n4  5  1  0\n\n## data.table \uc774\uc6a9\n> library(data.table)\n> dt &lt;- data.table(df)\n> dt&#91;x2 == 1&#93;\n   no x1 x2\n1:  4  1  1\n> dt&#91;x2 != 1&#93;\n   no x1 x2\n1:  1  1  0\n2:  5  1  0\n> dt&#91;x2 != 1 | is.na(x2)&#93;\n   no x1 x2\n1:  1  1  0\n2:  2  0 NA\n3:  3  0 NA\n4:  5  1  0\n<\/textarea><\/pre><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9FF\">## <\/span><span style=\"color: #D8DEE9\">subset<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">\ud568\uc218<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">\uc774\uc6a9<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">subset<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">subset<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">subset<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">|<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">is<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">na<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">## <\/span><span style=\"color: #D8DEE9\">dplyr<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">filter<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">\uc774\uc6a9<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">library<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">dplyr<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">%&gt;%<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">filter<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">%&gt;%<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">filter<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\"> <\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">%&gt;%<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">filter<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">|<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">is<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">na<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">## <\/span><span style=\"color: #D8DEE9\">data<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9\">table<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">\uc774\uc6a9<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">library<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">data<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9\">table<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">dt<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">&lt;-<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">data<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">table<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">df<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">dt<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">&#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">   <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">dt<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">&#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">   <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">dt<\/span><span style=\"color: #D8DEE9FF\">&#91;<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">|<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">is<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">na<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #D8DEE9\">x2<\/span><span style=\"color: #D8DEE9FF\">)&#93;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">   <\/span><span style=\"color: #D8DEE9\">no<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x1<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">x2<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">3<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">NA<\/span><\/span>\n<span class=\"line\"><span style=\"color: #B48EAD\">4<\/span><span style=\"color: #D8DEE9FF\">:  <\/span><span style=\"color: #B48EAD\">5<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\ub2e4\ub978 \ubc29\ubc95\ub4e4\uc774 \uadf8\ub098\ub9c8 \ub35c \uc9c0\uc800\ubd84\ud574 \ubcf4\uc774\uc9c0\ub9cc, &#8216;1 \uc544\ub2cc \uac83\uc5d0 NA \ub3c4 \ud3ec\ud568\ub418\uac8c&#8217;\ud560 \ubb54\uac00 \ub354 \uae54\ub054\ud55c \ubc29\ubc95\uc740 \ucc3e\uc9c0 \ubabb\ud588\uc2b5\ub2c8\ub2e4. NA \ub97c \ub2e4\ub8e8\ub294\ub370 is.na() \ub294 \ud53c\ud560 \uc218 \uc5c6\ub294 \ud568\uc218\uc778\uac00 \ubd05\ub2c8\ub2e4. \ud53c\ud560 \uc218 \uc5c6\uc73c\uba74 \uc990\uae30\ub7ac\ub098&#8230; \u3160\u3160<\/p>\n\n\n\n<p>2018. 8. 20.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>R \uc740 \ud1b5\uacc4 \ubd84\uc57c\uc5d0\uc11c (\ud2b9\ud788 data science \ucabd) \ub300\uc138\ub77c\uace0 \ud560 \uc218 \uc788\uc9c0\uc694. \uba87\ub144 \uc804\ubd80\ud130 R\uc744 \uc775\ud600 \ub370\uc774\ud130 \ubd84\uc11d\uc5d0 \uc774\uc6a9\ud558\uace0 \uc788\ub294\ub370, \ub9ce\uc740 \uc7a5\uc810\uc774 \uc788\uc73c\ub098 \uac00\ub054 \uc804\ud600 \uc9c1\uad00\uc801\uc774\uc9c0 \uc54a\ub294 \uacb0\uacfc\ub97c \ub0b4\ub358\uc9c0\ub294 \uacbd\uc6b0\uac00 \uc788\uc5b4 \uba58\ubd95\ud588\ub358 \uc801\uc774 \uc5ec\ub7ec\ubc88 \uc788\uc5c8\uc2b5\ub2c8\ub2e4. \uadf8 \uc9c1\uad00\uc774\ub780 \uac83\uc774 \uc9c0\uadf9\ud788 \uc778\uac04\uc801\uc778 \uac83\uc774\uace0 \uc0ac\uc2e4\uc740 R \uc774\ub77c\ub294 \ud504\ub85c\uadf8\ub798\ubc0d \uc5b8\uc5b4\ub97c \uc81c\ub300\ub85c \uc774\ud574 \ubabb\ud55c \ub54c\ubb38\uc5d0 \uc0dd\uae30\ub294 \uc77c\ub4e4\uc774\uc9c0\ub9cc, SAS\ub098 Stata \uc640 \uac19\uc740 \ud1b5\uacc4 \ud328\ud0a4\uc9c0\ub4e4\uc744 \ub2e4\ub8e8\uba74\uc11c\ub294 \uacaa\uc9c0 \uc54a\uc558\ub358 \uad34\uc0c1\ud55c \uc624\ub958\uc5d0 \uc2dc\ub2ec\ub9ac\ub294 \uac83\uc774 \uc369 \uae30\ubd84 \uc88b\uc9c0\ub294 \uc54a\uc740 \uc77c\uc774\uc9c0\uc694. \uadf8 \uc911 \ub300\ud45c\uc801\uc778 \uac83 \uc911 \ud558\ub098\uac00 NA \uad00\ub828\uc785\ub2c8\ub2e4. missing data \ub97c R \uc774 \ub2e4\ub8e8\ub294 \ubc29\ubc95\uc774 \ubb34\ucc99 \uc5c4\uaca9\ud558\ub2ec\uae4c\uc694, \uc774\uac78 \uc774\ud574 \ubabb\ud558\uba74 \uc815\ub9d0 \uad34\uc774\ud55c \uc5d0\ub7ec\uc5d0 \uba38\ub9ac\ub97c \uc950\uc5b4 \ub72f\uac8c \ub429\ub2c8\ub2e4. \ub2e4\uc74c\uacfc \uac19\uc740 \uc608\ub97c<\/p>\n","protected":false},"author":1,"featured_media":1165,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,3],"tags":[],"class_list":["post-406","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-biostatistics","category-research"],"views":2264,"_links":{"self":[{"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/posts\/406","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=406"}],"version-history":[{"count":13,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/posts\/406\/revisions"}],"predecessor-version":[{"id":1182,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/posts\/406\/revisions\/1182"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/media\/1165"}],"wp:attachment":[{"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=406"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=406"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jazzman.pe.kr\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=406"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}