{"id":1177,"date":"2019-04-28T06:58:34","date_gmt":"2019-04-27T21:58:34","guid":{"rendered":"http:\/\/141.164.34.82\/?p=1177"},"modified":"2019-05-03T01:13:19","modified_gmt":"2019-05-02T16:13:19","slug":"rolling-join","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=1177","title":{"rendered":"Rolling Join"},"content":{"rendered":"

\ub370\uc774\ud130\ud14c\uc774\ube14\uc758 Rolling-join<\/h1>\n

\ub370\uc774\ud130 \ud14c\uc774\ube14\uc740 dplyr<\/code>\ubcf4\ub2e4 \ud6e8\uc52c \ube60\ub97c \ubfd0 \uc544\ub2c8\ub77c, dplyr<\/code>\uc5d0\uc11c \uc9c0\uc6d0\ud558\uc9c0 \uc54a\ub294 \uae30\ub2a5\ub3c4 \uac00\uc9c0\uace0 \uc788\ub2e4. \uadf8 \uc911\uc758 \ud558\ub098\uac00 Rolling-join\uc774\ub2e4.<\/p>\n

Rolling-join\uc740 \uae30\uc900\ub418\ub294 \uceec\ub7fc\uc774 \ub3d9\uc77c\ud558\uc9c0 \uc54a\uc544\ub3c4 \ubcd1\ud569\ub418\uae30\uc5d0 inequality join\uc758 \ud558\ub098\uc774\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \uc811\uc18d \ub370\uc774\ud130\uc640 \uad6c\ub9e4 \ub370\uc774\ud130\ub97c \ud569\uce58\uace0 \uc2f6\ub2e4\uace0 \ud574\ubcf4\uc790. \uc811\uc18d \uc2dc\uac01\uacfc \uad6c\ub9e4 \uc2dc\uac01\uc774 \uc644\uc804\ud788 \uc77c\uce58\ud560 \uc218\ub294 \uc5c6\ub2e4. \uad6c\ub9e4\uc2dc\uac04 time_purchase \uac12\uc774 \uc788\uc744 \ub54c, \uc774\ubcf4\ub2e4 \uc774\ub974\uace0, \uac00\uc7a5 \uadfc\uc811\ud55c \uc811\uc18d \uc2dc\uac04 time_connect\ub97c \uc5f0\uacb0\ud558\uace0 \uc2f6\ub2e4\uba74 Rolling-join\uc744 \uc4f8 \uc218 \uc788\ub2e4.<\/p>\n

\uc608\ub97c \ub4e4\uc5b4 \ucca0\uc218<\/strong>\ub294 3\uc6d4 14\uc77c 10\uc2dc, 3\uc6d4 15\uc77c 11\uc2dc, 3\uc6d4 16 14\uc2dc\uc5d0 \uc811\uc18d\uc744 \ud588\uace0, 3\uc6d4 15\uc77c 13\uc2dc\uc5d0 \uc5b4\ub5a4 \uc0c1\ud488\uc744 \uad6c\ub9e4\ud588\ub2e4\uace0 \ud574\ubcf4\uc790.<\/p>\n\n\n\n\n\n\n\n
\uc811\uc18d \uc2dc\uac04<\/th>\n\uc811\uc18d \uc704\uce58<\/th>\n<\/tr>\n<\/thead>\n
03\/14 10:00<\/td>\n222.103.41.37<\/td>\n<\/tr>\n
03\/15 11:00<\/td>\n224.112.52.14<\/td>\n<\/tr>\n
03\/16 14:00<\/td>\n221.103.41.37<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n
\uad6c\ub9e4 \uc2dc\uac04<\/th>\n\uad6c\ub9e4 \uc0c1\ud488<\/th>\n<\/tr>\n<\/thead>\n
03\/15 13:00<\/td>\n\uc2a4\ud3ec\uce20\ucc28<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uc774 \ub450 \ud14c\uc774\ube14\uc740 \uae30\uc874\uc758 \ubc29\ubc95\uc73c\ub85c \ubcd1\ud569\ud560 \uc218 \uc5c6\ub2e4. \uc65c\ub0d0\ud558\uba74 \uc811\uc18d \uc2dc\uac04\uacfc \uad6c\ub9e4\uc2dc\uac04\uc774 \uc815\ud655\ud558\uac8c \uc77c\uce58\ud558\ub294 \uc5f4\uc740 \uc5c6\uae30 \ub54c\ubb38\uc774\ub2e4. \ubc18\uba74 \ud1b5\uc0c1\uc801\uc73c\ub85c \uc811\uc18d\uc774 \uc774\ub8e8\uc5b4\uc9c4 \ud6c4, \uad6c\ub9e4\uac00 \uc644\ub8cc\ub418\uae30 \ub54c\ubb38\uc5d0 \uc811\uc18d\uacfc \uad6c\ub9e4 \ud589\uc704\ub97c \uc5f0\uacb0\ud558\uae30 \uc704\ud574\uc11c\ub294 \uc811\uc18d \uc2dc\uac04\uc740 \uad6c\ub9e4\uc2dc\uac04\ubcf4\ub2e4 \uc774\ub978 \uc2dc\uac04\uc774\uba70 \ub2e4\ub978 \uc5f4\uacfc \ube44\uad50\ud588\uc744 \ub54c \uac00\uc7a5 \uac00\uae4c\uc6cc\uc57c \ud55c\ub2e4. \uc774\ub7f0 \uacbd\uc6b0 Rolling-join\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.<\/p>\n

\ud615\uc2dd\uc740 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n

DT1[DT2, on=' ', roll= ]\r\n<\/pre>\n
\ub2e4\uc74c\uc740 \uc870\uae08 \ub2e4\ub978 \uc608\uc774\ub2e4.<\/p>\n
library(data.table)\r\nDTA = data.table(\r\n  date = as.Date(c('2018-12-31', '2019-1-4', '2019-1-9')),\r\n  duration = c(60, 30, 40))\r\nDTB = data.table(\r\n  date = as.Date(c('2018-1-2', '2019-1-5', '2019-1-6')),\r\n  product = c('Cosmetics', 'Toys', 'Books'))\r\n<\/code><\/pre>\n\n\n\n\n\n\n\n
date<\/th>\nduration<\/th>\n<\/tr>\n<\/thead>\n
2018-12-31<\/td>\n60<\/td>\n<\/tr>\n
2019-01-04<\/td>\n30<\/td>\n<\/tr>\n
2019-01-09<\/td>\n40<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n
_<\/th>\n<\/tr>\n<\/thead>\n
<\/td>\n<\/tr>\n
<\/td>\n<\/tr>\n
<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n
date<\/th>\nproduct<\/th>\n<\/tr>\n<\/thead>\n
2018-01-02<\/td>\nCosmetics<\/td>\n<\/tr>\n
2019-01-05<\/td>\nToys<\/td>\n<\/tr>\n
2019-01-06<\/td>\nBooks<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n