合并日期和时间，在R中求时差

Question

我有一个数据集，并且有一些日期和时间属性。这是示例，然后我将解释我要做什么；

date1	hour1	date2	hour2	date3	hour3
2014-03-16 00:00:00	16:20:00	2014-03-16 00:00:00	20:20:03	2014-03-16 00:00:00	22:12:34
2014-04-22 00:00:00	10:20:00	2014-04-22 00:00:00	15:20:03	2014-04-22 00:00:00	20:12:34
2015-03-12 00:00:00	16:20:00	2015-03-12 00:00:00	20:20:03	2015-03-12 00:00:00	22:12:34

我们知道 event1 在 event2 之前发生（event1 -> event2 -> event3）

但是如您所见，在日期属性中，时间部分不正确，但我们每个都有小时属性。我想做的事;我想通过使用小时属性来更正它们，然后找到这两个日期之间的差异并创建以小时为时间差的新属性。

上表示例；

event2_time
4
5
4

我试图合并小时到日期并创建一个这样的新属性，但它不起作用。（我的目标实际上是更正日期值并摆脱小时属性）

trainTable <- trainTable %>%
   mutate("newParam" = as.POSIXct(paste(alert_date, alert_hour), format="%Y-%m-%d %H:%M:%S")

我需要一些帮助，在此先感谢。

数据

structure(list(alert_date = structure(c(1394928000, 1395014400, 
1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), alert_hour = c("16:15:00", "20:53:00", "12:55:00", 
"14:22:00", "12:07:00", "17:48:00"), firstInterv_date = structure(c(1394928000, 
1395014400, 1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), firstInterv_hour = c("16:35:00", "21:05:00", "13:10:00", 
"14:42:00", "12:07:00", "18:08:00"), extinction_date = structure(c(1394928000, 
1395014400, 1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), extinction_hour = c("17:47:00", "22:46:00", "15:30:00", 
"15:25:00", "13:14:00", "21:10:00")), row.names = c(NA, -6L), class = c("tbl_df", 
"tbl", "data.frame"))

Answer 1

使用mapply 尝试此解决方案。它使用strsplit 将日期与小时分开。

dat <- as.data.frame( dat ) # tibbles are cool but sometimes very restrictive, so changing to data.frame here

dat_new <- data.frame( setNames( mapply( function(x,y){
  tmp <- sapply( strsplit( as.character(dat[,x]), " "), function(z) z[1] );
  list( as.POSIXct( paste(tmp,dat[,y] ) ) ) },
  grep("date", colnames(dat)), grep("hour", colnames(dat)) ), 
  c("a","b","c") ) )

dat_new$b - dat_new$a
Time differences in secs
[1] 1200  720  900 1200    0 1200

# if you need tibbles convert back if you need
as_tibble( dat_new )
# A tibble: 6 x 3
  a                   b                   c                  
  <dttm>              <dttm>              <dttm>             
1 2014-03-16 16:15:00 2014-03-16 16:35:00 2014-03-16 17:47:00
2 2014-03-17 20:53:00 2014-03-17 21:05:00 2014-03-17 22:46:00
3 2014-03-17 12:55:00 2014-03-17 13:10:00 2014-03-17 15:30:00
4 2014-03-19 14:22:00 2014-03-19 14:42:00 2014-03-19 15:25:00
5 2014-03-20 12:07:00 2014-03-20 12:07:00 2014-03-20 13:14:00
6 2014-03-17 17:48:00 2014-03-17 18:08:00 2014-03-17 21:10:00

数据

dat <- structure(list(alert_date = structure(c(1394928000, 1395014400, 
1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), alert_hour = c("16:15:00", "20:53:00", "12:55:00", 
"14:22:00", "12:07:00", "17:48:00"), firstInterv_date = structure(c(1394928000, 
1395014400, 1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), firstInterv_hour = c("16:35:00", "21:05:00", "13:10:00", 
"14:42:00", "12:07:00", "18:08:00"), extinction_date = structure(c(1394928000, 
1395014400, 1395014400, 1395187200, 1395273600, 1395014400), tzone = "UTC", class = c("POSIXct", 
"POSIXt")), extinction_hour = c("17:47:00", "22:46:00", "15:30:00", 
"15:25:00", "13:14:00", "21:10:00")), row.names = c(NA, -6L), class = c("tbl_df", 
"tbl", "data.frame"))