R 如果满足条件,则替换第一个日期实例
我在dataframe中有如下快照数据:R 如果满足条件,则替换第一个日期实例,r,dplyr,R,Dplyr,我在dataframe中有如下快照数据: zz <- "id created snap stage ALPHA 2012-09-07 2014-01-02 A ALPHA 2012-09-07 2014-10-01 End BETA 2012-08-26 2014-01-04 B BETA 2012-08-26 2014-06-19 C BETA 2012-08-26 2014-11-21 End GAMMA 2014-01-04
zz <- "id created snap stage
ALPHA 2012-09-07 2014-01-02 A
ALPHA 2012-09-07 2014-10-01 End
BETA 2012-08-26 2014-01-04 B
BETA 2012-08-26 2014-06-19 C
BETA 2012-08-26 2014-11-21 End
GAMMA 2014-01-04 2014-01-04 A
GAMMA 2014-01-04 2014-03-07 B
GAMMA 2014-01-04 2014-03-28 C
GAMMA 2014-01-04 2014-03-29 End
DELTA 2014-07-14 2014-07-15 A
DELTA 2014-07-14 2014-09-26 C
DELTA 2014-07-14 2015-02-06 End"
df <- read.table(text=zz, header = T)
请注意,GAMMA
和DELTA
保持不变,但阶段A
中的ALPHA
替换了快照日期,阶段B
中的BETA
也替换了快照日期,请尝试以下操作:
library(data.table)
setDT(df)[, snap := if (created[1L] < as.Date('2014-01-01'))
c(created[1L], snap[-1L]), by = id]
这里有一个dplyr方法——我从“mutate_each”开始,以确保“created”和“snap”都被格式化为正确的日期。然后,我们按照“id”对数据进行分组,最后使用“mutate”和“replace”对“snap”列进行所需的更改(我们检查创建的位置在截止日期之前,行号为1,即该id组中的第一行):
库(dplyr)
df%>%
每个(funs(截止日期(%))、创建、捕捉)%>%
分组依据(id)%>%
突变(snap=replace(snap,创建日期
您是否运行此命令并获得所需的输出?我犯了个错误。您当然需要将数据转换为“data.table”,例如使用setDT
,而不需要在“[”内使用mydata$
。
library(data.table)
setDT(df)[, snap := if (created[1L] < as.Date('2014-01-01'))
c(created[1L], snap[-1L]), by = id]
cols = c("snap", "created")
df[, (cols) := lapply(.SD, as.Date), .SDcols=cols]
library(dplyr)
df %>%
mutate_each(funs(as.Date(.)), created, snap) %>%
group_by(id) %>%
mutate(snap = replace(snap, which(created < as.Date("2014-01-01") & row_number() == 1), created))
#Source: local data frame [12 x 4]
#Groups: id
#
# id created snap stage
#1 ALPHA 2012-09-07 2012-09-07 A
#2 ALPHA 2012-09-07 2014-10-01 End
#3 BETA 2012-08-26 2012-08-26 B
#4 BETA 2012-08-26 2014-06-19 C
#5 BETA 2012-08-26 2014-11-21 End
#6 GAMMA 2014-01-04 2014-01-04 A
#7 GAMMA 2014-01-04 2014-03-07 B
#8 GAMMA 2014-01-04 2014-03-28 C
#9 GAMMA 2014-01-04 2014-03-29 End
#10 DELTA 2014-07-14 2014-07-15 A
#11 DELTA 2014-07-14 2014-09-26 C
#12 DELTA 2014-07-14 2015-02-06 End