r语言 - Generate column id

Question

我正在处理日志数据;试图找到每个事件的整数。一轮的开始由 action=="start" 发出信号。我想创建一个"action.round"列，告诉我每个事件对应于哪个回合。

我有这样的数据：

data <- read_table2("Id action 
A   start
A   na
A   start
A   na
A   na
A   na
A   na
A   start
B   start
B   na
B   start
B   na
B   start
B   na" 

我正在尝试创建如下输出：

output <- read_table2("Id   action  action.round
A   start   1
A   na  1
A   start   2
A   na  2
A   na  2
A   na  2
A   na  2
A   start   3
B   start   1
B   na  1
B   start   2
B   na  2
B   start   3
B   na  3")

到目前为止，我已经能够使用 row_number(( 获取部分输出，如下所示：

` data %>% 
mutate(round.start=case_when(actionValue=="start"~"start",TRUE~"NA")) %>%
ungroup() %>%
group_by(Id,round.start) %>%
mutate(action.round=row_number())`

但是现在，我想将对应于round.start=="start"的整数填充到列中，以便我知道每列实际上对应于哪个整数(请参阅上面的所需输出(。

Answer 1

您可以在按Id分组后使用cumsum。

library(dplyr)
data %>% group_by(Id) %>% mutate(action.round = cumsum(action == "start"))
#   Id    action action.round
#  <chr>  <chr>         <int>
# 1 A     start            1
# 2 A     na               1
# 3 A     start            2
# 4 A     na               2
# 5 A     na               2
# 6 A     na               2
# 7 A     na               2
# 8 A     start            3
# 9 B     start            1
#10 B     na               1
#11 B     start            2
#12 B     na               2
#13 B     start            3
#14 B     na               3

这可以在基础 R 中完成

data$action.round <- with(data, ave(action == "start", Id, FUN = cumsum))

以及data.table

library(data.table)
setDT(data)[, action.round := cumsum(action == "start"), Id]

数据

data <- structure(list(Id = c("A", "A", "A", "A", "A", "A", "A", "A", 
"B", "B", "B", "B", "B", "B"), action = c("start", "na", "start", 
"na", "na", "na", "na", "start", "start", "na", "start", "na", 
"start", "na")), row.names = c(NA, -14L), spec = structure(list(
cols = list(Id = structure(list(), class = c("collector_character", 
"collector")), action = structure(list(), class = c("collector_character", 
"collector")), action.round = structure(list(), class = c("collector_double", 
"collector"))), default = structure(list(), class = c("collector_guess", 
"collector")), skip = 1), class = "col_spec"), class = c("spec_tbl_df", 
"tbl_df", "tbl", "data.frame"))