如何将特定时间格式转换为R中的时间戳？

首先，我们需要将从毫秒到毫秒的冒号分隔开来，否则最后一步将不起作用（感谢 Dirk Eddelbuettel ）因为最终R将使用它想要的分隔符，要更快，我会继续，替换所有的冒号点：

First of all, we need to substitute the colon separating the milliseconds from the seconds to a dot, otherwise the final step won't work (thanks to Dirk Eddelbuettel for this one). Since in the end R will use the separators it wants, to be quicker, I'll just go ahead and substitute all the colons for dots:

x <- "27.05.2009 14:03:25:777"  # this is a simplified version of your data
y <- gsub(":", ".", x)          # this is your vector with the aforementioned substitution

顺便说一下，这是你的矢量应该照顾 gsub ：

By the way, this is how your vector should look after gsub:

> y
[1] "27.05.2009 14.03.25.777"

现在，为了它显示毫秒，您首先需要调整R选项，然后使用一个名为 strptime 的函数，这将将您的日期向量转换为POSIXlt（一个R友好的）格式。只需执行以下操作：

Now, in order to have it show the milliseconds, you first need to adjust an R option and then use a function called strptime, which will convert your date vector to POSIXlt (an R-friendly) format. Just do the following:

> options(digits.secs = 3)           # this tells R you want it to consider 3 digits for seconds.
> strptime(y, "%d.%m.%Y %H:%M:%OS")  # this finally formats your vector
[1] "2009-05-27 14:03:25.777"

我学到了这个很棒的技巧这里。 另一个答案也表示您可以跳过选项设置并使用，例如， strptime（y，％d。％m。％Y％H：％M：％OS3），但对我来说不起作用。 Henrik 指出，功能的帮助页面？strptime 指出，％OS3 位是与操作系统相关的。我正在使用更新的Ubuntu 13.04，并使用％OS3 产生 NA 。

I've learned this nice trick here. This other answer also says you can skip the options setting and use, for example, strptime(y, "%d.%m.%Y %H:%M:%OS3"), but it doesn't work for me. Henrik noted that the function's help page, ?strptime states that the %OS3 bit is OS-dependent. I'm using an updated Ubuntu 13.04 and using %OS3 yields NA.

使用 strptime （或其他与POSIX相关的功能，如 as.Date ）时，请保留考虑到使用的一些最常用的转换（根据 DWin 的建议，为了简洁而进行编辑。完整列表 strptime ）：

When using strptime (or other POSIX-related functions such as as.Date), keep in mind some of the most common conversions used (edited for brevity, as suggested by DWin. Complete list at strptime):

• ％a 当前语言环境中的缩位工作日名称。


• ％A 当前区域的全部工作日名称。


• ％b 当前区域设置中的缩写月份名称。


• ％B 当前区域设置中的全月份名称。 >
  
• ％d 以十进制数（01-31）为单位的日期。


• ％H 小时数为十进制数（00-23）。时间如24:00:00接受输入。


• ％I 小时数为十进制数（01-12）。


• ％j 年份为十进制数（001-366）。


• ％m 十进制数月份（01-12）


• ％M 分钟作为十进制数（00-59）。


• ％p 本地区的AM / PM指标。与％I 而不是与％H 。


• ` ％S第二个十进制数（00-61），允许最多两个闰秒（但POSIX兼容的实现将忽略闰秒）。


• ％ U 使用星期日作为十进制数（00-53）的一周中的星期，作为一周的第一天（通常为第一周的第1个星期日）。


• ％w 平日为十进制数（0-6，星期日为0）


• ％W 使用星期一作为十进制数（00-53）的一周中的星期几（通常与当年的第一个星期一）作为第1周的第1天）。


• ％y 没有世纪的年份（00-99）。在输入上，值00至68的前缀为20和69至99之间。19


• ％Y 具有世纪的年份。请注意，虽然原始公历中没有零，但ISO 8601：2004定义为有效（解释为1BC）

• %a Abbreviated weekday name in the current locale.
• %A Full weekday name in the current locale.
• %b Abbreviated month name in the current locale.
• %B Full month name in the current locale.
• %d Day of the month as decimal number (01–31).
• %H Hours as decimal number (00–23). Times such as 24:00:00 are accepted for input.
• %I Hours as decimal number (01–12).
• %j Day of year as decimal number (001–366).
• %m Month as decimal number (01–12).
• %M Minute as decimal number (00–59).
• %p AM/PM indicator in the locale. Used in conjunction with %I and not with %H.
• `%S Second as decimal number (00–61), allowing for up to two leap-seconds (but POSIX-compliant implementations will ignore leap seconds).
• %U Week of the year as decimal number (00–53) using Sunday as the first day 1 of the week (and typically with the first Sunday of the year as day 1 of week 1). The US convention.
• %w Weekday as decimal number (0–6, Sunday is 0).
• %W Week of the year as decimal number (00–53) using Monday as the first day of week (and typically with the first Monday of the year as day 1 of week 1). The UK convention.
• %y Year without century (00–99). On input, values 00 to 68 are prefixed by 20 and 69 to 99 by 19
• %Y Year with century. Note that whereas there was no zero in the original Gregorian calendar, ISO 8601:2004 defines it to be valid (interpreted as 1BC)