Question

我有一个类似于dd的数据框

dd = data.frame(date = as.Date(c("2014-04-29", "2014-04-29","2014-04-29", "2014-04-29", "2014-04-29", "2014-04-29"), format ="%Y-%m-%d"), hh = 1:6, mm = seq(0, 50, 10))

我想创建新变量，将其称为time1和time2，其中

time1是一天中的时间，无论日期如何，例如：第1行time1 = 01:00 [hh：mm]没有条目进入
time2是date + time1;例如第1行time2 = 2014-04-29 : 01:00

任何建议都表示赞赏！

Answer 1

查看lubridate包：

library(lubridate)
dd$time1 <- with(dd, hm(paste(hh, mm, sep=":")))
dd$time2 <- with(dd, ymd(dd$date) + time1)

Answer 2

使用基础R

dd$time1 <- format(strptime(paste0(dd$hh, ":", dd$mm), "%H:%M"), "%H:%M")
dd$time2 <- format(strptime(paste0(dd$date, ":", dd$hh, ":", dd$mm), "%Y-%m-%d:%H:%M"), "%Y-%m-%d : %H:%M")

这将导致

dd$time1
## [1] "01:00" "02:10" "03:20" "04:30" "05:40" "06:50"
dd$time2
## [1] "2014-04-29 : 01:00" "2014-04-29 : 02:10" "2014-04-29 : 03:20" "2014-04-29 : 04:30"
##v[5] "2014-04-29 : 05:40" "2014-04-29 : 06:50"

虽然他们不会成为Date类型（请参阅@MrFlick评论）

在R中将日期，分钟和秒转换为ISOdatetime格式

2 个答案: