从 R 中的时间中删除秒数

Question

我正在尝试从 POSIXct 格式的小时列中删除秒：

#"2016-04-02 10:33:45 COT" "2016-04-02 22:19:24 COT"
#"2016-04-09 17:47:13 COT" "2016-04-13 16:56:23 COT"

x <- structure(c(1459589625, 1459631964, 1460220433, 1460562983),
     class = c("POSIXct", "POSIXt"), tzone = "")

我正在尝试这个，但我没有看到结果：

y <- as.POSIXct(x, format = "%d/%m/%Y %H:%M")

Answer 1

不，你给了

as.POSIXct

一个错误的格式...

使用格式怎么样

datetimes = as.POSIXct(c("2016-04-02 10:33:45 COT", "2016-04-02 22:19:24 COT" ,"2016-04-09 17:47:13 COT", "2016-04-13 16:56:23 COT")    
format(datetimes,format='%Y%m%d %H:%M')

[1] "20160402 10:33" "20160402 22:19" "20160409 17:47" "20160413 16:56"

Answer 2

你可以使用 round.POSIXt:

round(Sys.time(), units = "mins")
#"2017-01-30 11:20:00 CET"

Answer 3

这就是你所拥有的：

x <- structure(c(1459589625, 1459631964, 1460220433, 1460562983),
     class = c("POSIXct", "POSIXt"), tzone = "")

这就是你想要的：

x <- format(as.POSIXct(x), "%d-%m-%Y %H:%M")
x

[1] "02-04-2016 15:03" "03-04-2016 02:49" "09-04-2016 22:17" "13-04-2016 21:26"

Answer 4

如果您想将日期四舍五入为分钟，您可以这样做：

   x <- as.POSIXlt(c("2016-04-02 10:33:45 COT"))
   res <-as.POSIXlt(floor(as.double(x) / 60) * 60, origin = '1970-01-01')
   res
   #  "2016-04-02 10:33:00 BST"

Answer 5

只需使用子字符串：

datetimes <- c("2016-04-02 10:33:45 COT", "2016-04-02 22:19:24 COT" ,
               "2016-04-09 17:47:13 COT", "2016-04-13 16:56:23 COT")

as.POSIXct(substring(datetimes, 1, nchar(datetimes[1])-7))   

#[1] "2016-04-02 10:33:00 IST" "2016-04-02 22:19:00 IST" 
#    "2016-04-09 17:47:00 IST" "2016-04-13 16:56:00 IST"

# without timezone
format(substring(datetimes, 1, nchar(datetimes[1])-7), 
                 format='%Y-%m-%d %H:%M:%S', usetz = FALSE)
#[1] "2016-04-02 10:33" "2016-04-02 22:19" "2016-04-09 17:47" "2016-04-13 16:56"

Answer 6

lubridate::floor_date(datetimes, unit = "minutes")