{"id":2302,"date":"2021-02-24T18:35:20","date_gmt":"2021-02-24T09:35:20","guid":{"rendered":"http:\/\/141.164.34.82\/?p=2302"},"modified":"2021-03-15T03:37:07","modified_gmt":"2021-03-14T18:37:07","slug":"ifelse%eb%8a%94-date%eb%a5%bc-%ec%8b%ab%ec%96%b4%ed%95%b4","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=2302","title":{"rendered":"`ifelse`\ub294 `Date`\ub97c \uc2eb\uc5b4\ud574"},"content":{"rendered":"

ifelse<\/code><\/h2>\n

Hadley\uac00 \uc4f4 Advanced R(2nd ed.)\uc744 \ubcf4\uba74, ifelse<\/code>\uc5d0 \ub300\ud574 \uc774\ub807\uac8c \uc124\uba85\ud55c\ub2e4.<\/p>\n

ifelse(cond, yes, no)<\/code>\ub294 yes<\/code>\uc640 no<\/code>\uac00 \uac19\uc740 \ud0c0\uc785\uc77c \ub54c\ub9cc \uc4f0\uae38 \uad8c\uc7a5\ud55c\ub2e4. \ub9cc\uc57d yes<\/code>\uc640 no<\/code>\uc758 \ud0c0\uc785\uc774 \ub2e4\ub974\ub2e4\uba74 \uacb0\uacfc \ud0c0\uc785\uc744 \uc815\ud655\ud558\uac8c \uc608\uce21\ud558\uae30\uac00 \uc5b4\ub835\ub2e4.<\/p><\/blockquote>\n

\uc544\ub9c8\ub3c4 \uc544\ub798\uc640 \uac19\uc774 \uc870\uac74(cond<\/code>)\uc744 \ubaa8\ub450 \ub9cc\uc871\ud558\ub290\ub0d0, \uadf8\ub807\uc9c0 \uc54a\ub290\ub0d0\uc5d0 \ub530\ub77c \uacb0\uacfc \ubca1\ud130\uc758 \ud0c0\uc785\uc774 \ub2ec\ub77c\uc9c8 \uc218 \uc788\uc74c\uc744 \uc6b0\ub824\ud55c \uac83 \uac19\ub2e4.<\/p>\n

x <- c(0,1,2,3)\r\nifelse(x > 1, \"Yes\", TRUE)  # \uacb0\uacfc : \ubb38\uc790\r\n<\/code><\/pre>\n
## [1] \"TRUE\" \"TRUE\" \"Yes\"  \"Yes\"\r\n<\/pre>\n
ifelse(x > -1, \"Yes\", TRUE) #        \ubb38\uc790\r\n<\/code><\/pre>\n
## [1] \"Yes\" \"Yes\" \"Yes\" \"Yes\"\r\n<\/pre>\n
ifelse(x > 4, \"Yes\", TRUE)  #        \ub17c\ub9ac\r\n<\/code><\/pre>\n
## [1] TRUE TRUE TRUE TRUE\r\n<\/pre>\n
\uc0ac\uc2e4 Hadley\ub294 \uacb0\uacfc \ubca1\ud130\uac00 \ud56d\uc0c1 \ub3d9\uc77c\ud55c \ud615\ud0dc\uac00 \ub418\ub294 \uac83\uc744 \uc88b\uc544\ud558\uba70, R\uc758 \ub9ce\uc740 \ud568\uc218\ub97c \uadf8\ub7f0 \ubc29\uc2dd\uc73c\ub85c \uc218\uc815\ud558\uae30\ub3c4 \ud588\ub2e4. \ud558\uc9c0\ub9cc \uadf8\uac8c \uaf2d \ud760\uc77c \uc218\ub9cc\uc740 \uc5c6\ub2e4\uace0 \ubcf8\ub2e4.<\/p>\n
\uc608\ub97c \ub4e4\uc5b4 \uadf8 \ud754\ud55c recycling\uc758 \uacbd\uc6b0\ub3c4 \ub9ce\uc740 \ub17c\ub9ac \uc624\ub958\uc758 \uc6d0\uc778\uc774 \ub418\uae30\ub3c4 \ud558\uc9c0\ub9cc, \uadf8\uac78 \ub610 \uba85\uc2dc\uc801\uc73c\ub85c \uad6c\ud604\ud558\ub824\uace0 \ud558\uba74 \ubd88\ud3b8\ud55c\uac8c \uc0ac\uc2e4\uc774\ub2e4.<\/p>\n
\uc608\ub97c \ub4e4\uc5b4 \uc544\ub798\uc640 \uac19\uc774 \uac04\ub2e8\ud558\uac8c \uc4f8 \uc218 \uc788\ub294 \uacbd\uc6b0\uc5d0, recycling\uc774 \uc548 \ub41c\ub2e4\uba74,<\/p>\n
a = 1:4\r\nb = 1:3\r\ncbind(a,b)\r\n<\/code><\/pre>\n
## Warning in cbind(a, b): number of rows of result is not a multiple of vector length (arg 2)\r\n<\/pre>\n
##      a b\r\n## [1,] 1 1\r\n## [2,] 2 2\r\n## [3,] 3 3\r\n## [4,] 4 1\r\n<\/pre>\n
\ub2e4\uc74c\uacfc \uac19\uc774 \uc218\uace0\ub85c\uc6b4 \ubcc0\ud658 \uacfc\uc815\uc744 \uac70\uccd0\uc57c \ud55c\ub2e4.<\/p>\n
a = 1:4\r\nb = 1:3\r\nif ((la <- length(a))>(lb <- length(b))) {\r\n  repn <- la %\/% lb\r\n  remain <- la %% lb\r\n  b = c(rep(b, repn), b[1:remain])\r\n} else {\r\n  repn <- lb %\/% la\r\n  remain <- lb %% la\r\n  a = c(rep(a, repn), a[1:remain])\r\n}\r\ncbind(a,b)\r\n<\/code><\/pre>\n
##      a b\r\n## [1,] 1 1\r\n## [2,] 2 2\r\n## [3,] 3 3\r\n## [4,] 4 1\r\n<\/pre>\n
ifelse<\/code>! & Date<\/code><\/h2>\n
\uadf8\ub7f0\ub370 ifelse()<\/code>\ub294 \uacb0\uacfc\uc758 \ud0c0\uc785\ubcf4\ub2e4 \uc911\ub300\ud55c \uacb0\ud568\uc774 \uc788\uc5c8\ub2e4. \ub2e4\uc74c\uc740 ifelse()<\/code>\uc640\uc758 \uc778\ud130\ubdf0\uc774\ub2e4.<\/p>\n
\uc800\ub294 \ud0dc\uc0dd\uc801\uc73c\ub85c Date\ub97c \uc2eb\uc5b4\ud569\ub2c8\ub2e4. \uc6b0\ub9ac\uc5d0\uac8c \uc911\uc694\ud55c \uac83\uc740 Unix Epoch(1970-01-01)<\/a>\uc774\uc8e0. \uadf8\ub0a0\ub85c\ubd80\ud130 \uba87\uc77c\uc774\ub098 \uc9c0\ub0ac\ub294\uc9c0\ub9cc \uc54c\uba74 \ub429\ub2c8\ub2e4.<\/p><\/blockquote>\n
x <- as.Date(c('2011-01-03', '2022-04-01'))\r\nifelse(x > as.Date('2021-05-01'), as.Date('1970-01-01'), as.Date('2021-05-01'))\r\n<\/code><\/pre>\n
## [1] 18748     0\r\n<\/pre>\n
\ubc18\uba74 dplyr<\/code>\uc758 case_when<\/code>\uc740 \uc798 \uc791\ub3d9\ud558\ub294 \ub4ef\ud558\ub2e4.<\/p>\n
dplyr::case_when(\r\nx > as.Date('2014-05-01') ~ as.Date('2010-01-01'),\r\nTRUE ~ as.Date('2010-01-01')\r\n)\r\n<\/code><\/pre>\n
## [1] \"2010-01-01\" \"2010-01-01\"\r\n<\/pre>\n
ifelse<\/code>!! & POSIXct<\/code><\/h2>\n
\uc608\uc0c1\ub300\ub85c POSIXct<\/code>\uc758 \uacbd\uc6b0\ub3c4 \ub9c8\ucc2c \uac00\uc9c0 \ubb38\uc81c\uac00 \ubc1c\uc0dd\ud55c\ub2e4.<\/p>\n
x <- as.POSIXct(c('2011-01-03 13:14', '2022-04-01 01:01'))\r\nifelse(x > as.POSIXct('2021-05-01'), \r\n       as.POSIXct('1970-01-01 00:00'), \r\n       as.POSIXct('2021-05-01 12:00'))\r\n<\/code><\/pre>\n
## [1] 1619838000     -32400\r\n<\/pre>\n
dplyr::case_when( \r\n        x > as.POSIXct('2021-05-01') ~ as.POSIXct('1970-01-01 00:00'), \r\n        TRUE ~ as.POSIXct('2021-05-01 12:00')\r\n        )\r\n<\/code><\/pre>\n
## [1] \"2021-05-01 12:00:00 KST\" \"1970-01-01 00:00:00 KST\"\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
ifelse Hadley\uac00 \uc4f4 Advanced R(2nd ed.)\uc744 \ubcf4\uba74, ifelse\uc5d0 \ub300\ud574 \uc774\ub807\uac8c \uc124\uba85\ud55c\ub2e4. ifelse(cond, yes, no)\ub294 yes\uc640 no\uac00 \uac19\uc740 \ud0c0\uc785\uc77c \ub54c\ub9cc \uc4f0\uae38 \uad8c\uc7a5\ud55c\ub2e4. \ub9cc\uc57d yes\uc640 no\uc758 \ud0c0\uc785\uc774 \ub2e4\ub974\ub2e4\uba74 \uacb0\uacfc \ud0c0\uc785\uc744 \uc815\ud655\ud558\uac8c \uc608\uce21\ud558\uae30\uac00 \uc5b4\ub835\ub2e4. \uc544\ub9c8\ub3c4 \uc544\ub798\uc640 \uac19\uc774 \uc870\uac74(cond)\uc744 \ubaa8\ub450 \ub9cc\uc871\ud558\ub290\ub0d0, \uadf8\ub807\uc9c0 \uc54a\ub290\ub0d0\uc5d0 \ub530\ub77c \uacb0\uacfc \ubca1\ud130\uc758 \ud0c0\uc785\uc774 \ub2ec\ub77c\uc9c8 \uc218 \uc788\uc74c\uc744 \uc6b0\ub824\ud55c \uac83 \uac19\ub2e4. x <- c(0,1,2,3) ifelse(x > 1, […]<\/p>\n","protected":false},"author":1,"featured_media":2316,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[28,179,481],"tags":[482,181],"jetpack_featured_media_url":"http:\/\/ds.sumeun.org\/wp-content\/uploads\/2021\/02\/ifelse\ub294-Date\ub97c-\uc2eb\uc5b4\ud574-\u2013-\uc228\uc740\uc6d0\ub9ac-\ub370\uc774\ud130\uc0ac\uc774\uc5b8\uc2a4_-R\ub85c-\ud558\ub294-\ub370\uc774\ud130-\uc0ac\uc774\uc5b8\uc2a4-Chrome-2021-03-15-\uc624\uc804-3_35_28-2.png","_links":{"self":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2302"}],"collection":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2302"}],"version-history":[{"count":4,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2302\/revisions"}],"predecessor-version":[{"id":2317,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2302\/revisions\/2317"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/media\/2316"}],"wp:attachment":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2302"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}