问题
I have an integer which I want to convert to class Date. I assume I first need to convert it to a string, but how?
My attempt:
v <- 20081101
date <- as.Date(v, format("%Y%m%d"))
Error in charToDate(x) : character string is not in a standard unambiguous format
Using paste() works, but is that really the correct way to do the conversion?
date <- as.Date(paste(v), format("%Y%m%d"))
date
[1] "2008-11-01"
class(date)
# [1] "Date"
回答1:
as.character() would be the general way rather than use paste() for its side effect
> v <- 20081101
> date <- as.Date(as.character(v), format = "%Y%m%d")
> date
[1] "2008-11-01"
(I presume this is a simple example and something like this:
v <- "20081101"
isn't possible?)
回答2:
Another way to get the same result:
date <- strptime(v,format="%Y%m%d")
回答3:
You can use ymd from lubridate
lubridate::ymd(v)
#[1] "2008-11-01"
Or anytime::anydate
anytime::anydate(v)
#[1] "2008-11-01"
来源：https://stackoverflow.com/questions/4104359/convert-integer-to-class-date