【R】滅多に使わない前処理メモ

滅多に使わないが故にすぐ忘れてしまうこと必至の処理だったので、メモっておく。

cvが1のときにデータを区切るためのidを振りたい。

# library -----------------------------------------------------------------

require(random)
require(dplyr)


# makinkg data ------------------------------------------------------------

set.seed(71)
N <- 5
session_id <- as.vector(random::randomStrings(n = N,len = 8, digits = T, unique = T))
times <- floor(runif(N, min = 3, max = 10))

dat <- data.frame(
  session_id = rep(session_id, times),
  times = unlist(sapply(times, FUN = function(x) 1:x))
)
dat["cv"] <- rbinom(n = nrow(dat), size = 1, prob = 0.2)


# preprocess --------------------------------------------------------------

dat_pp <- dat %>% 
  dplyr::group_by(session_id) %>%
  dplyr::mutate(cv_cumsum = cumsum(cv)) %>% 
  dplyr::mutate(cv_id = dplyr::lag(cv_cumsum, n = 1, default = 0)) %>% 
  dplyr::select(session_id, cv_id, times, cv)

# check
tibble::glimpse(dat_pp)

　　
結果は以下の通り

 session_id cv_id times cv
1    H5bnOPEl     0     1  1
2    H5bnOPEl     1     2  0
3    H5bnOPEl     1     3  1
4    H5bnOPEl     2     4  0
5    H5bnOPEl     2     5  0
6    pXbymzES     0     1  0
7    pXbymzES     0     2  0
8    pXbymzES     0     3  0
9    pXbymzES     0     4  0
10   pXbymzES     0     5  1
11   pXbymzES     1     6  0
12   G60tnnDx     0     1  0
13   G60tnnDx     0     2  1
14   G60tnnDx     1     3  1
15   G60tnnDx     2     4  1
16   G60tnnDx     3     5  0
17   FokLEvUI     0     1  0
18   FokLEvUI     0     2  0
19   FokLEvUI     0     3  0
20   FokLEvUI     0     4  0
21   O0jUTbyT     0     1  0
22   O0jUTbyT     0     2  0
23   O0jUTbyT     0     3  0
24   O0jUTbyT     0     4  0
25   O0jUTbyT     0     5  1