R从多种格式转换为日期

Question

我需要将多种格式的日期字符串转换为有效日期.

例如

dates <- c("01-01-2017","02-01-2017","12-01-2016","20160901","20161001", "20161101")

> as.Date(dates, format=c("%m-%d-%Y","%Y%m%d"))
[1] "2017-01-01" NA           "2016-12-01" "2016-09-01" NA           "2016-11-01"

两个日期显示为NA

Answer 1

这几乎是我写的anytime包:

R> dates <- c("01-01-2017","02-01-2017","12-01-2016","20160901","20161001", 
+             "20161101")
R> library(anytime)
R> anydate(dates)
[1] "2017-01-01" "2017-02-01" "2016-12-01" "2016-09-01" 
[5] "2016-10-01" "2016-11-01"
R> 

可靠地解析任何合理的输入,没有明确的格式或原点或其他线路噪声.

话虽这么说,没有开始ISO风格的年份是要求潜在的麻烦,所以02-03-2017可能是2月3日或3月2日.我遵循北美大会我也认为有点破碎 - 但是非常普遍.帮自己一个忙,并尝试将输入限制为ISO日期,至少ISO订单YYYYMMDD.