将字符串转换为日期时间

Question

我正在尝试将数据集加载到 r 并将列的类型更改为日期时间。

strptime、as.POSIXct 或 as.Date 适用于不同的情况；

这是我的代码：

a <- structure(list(DATE = c("01/01/2011 12:00:00", "01/02/2011 12:00:00", 
   "01/03/2011 12:00:00", "01/04/2011 12:00:00", "01/05/2011 12:00:00", 
   "01/06/2011 12:00:00"), VAL = c(65.34447917, 65.23983333, 65.03183333, 
   64.89107292, 64.83333333, 64.848625), id = c("VT1-1", "VT1-1", "VT1-1", 
   "VT1-1", "VT1-1", "VT1-1")), .Names = c("DATE", "VAL", "id"), row.names = c(NA, -6L), 
   class = c("tbl_df", "tbl", "data.frame"))

b1 <- as.POSIXct(a$DATE, format = "%m/%d/%y %H:%M:%S")
b2 <- strptime(a$DATE,"%m/%d/%Y %H:%M/%S")

但他们只是 return NA。这很可能是一个错字；但是在处理不同的日期时间格式时如何避免这种情况呢？

Answer 1

R> library(anytime)
R> anytime(a$DATE)
[1] "2011-01-01 12:00:00 CST" "2011-01-02 12:00:00 CST" "2011-01-03 12:00:00 CST"
[4] "2011-01-04 12:00:00 CST" "2011-01-05 12:00:00 CST" "2011-01-06 12:00:00 CST"
R>

构建 anytime 包是为了让这一切变得简单——您不需要提供可能会出错的格式，它只是尝试一些看似合理的格式。对于 "reasonable" 输入， 正常工作。

将字符串转换为日期时间

Converting Character String to Datetime

r

datetime

posixct

strptime