找出R中一个月的天数
问题描述：
我有一个日期在P
date = as.Date("2011-02-23", "%Y-%m-%d")
是否可以找出当月的天数那个特定日期？ （关于leapyears）。在PHP中，它看起来与此类似（ http://www.php.net/ manual / en / function.date.php ）：
Is it possible to find out the number of days of the month of that particular date? (With respect to leapyears). In PHP it would look similar to this (http://www.php.net/manual/en/function.date.php):
days = format(date, "%t")
但％t似乎在R中有不同的含义。有没有解决这个问题？
but "%t" seems to have a different meaning in R. Is there a solution for this problem?
答
您可以编写简单的功能：
You can write simple function to do that:
numberOfDays <- function(date) {
m <- format(date, format="%m")
while (format(date, format="%m") == m) {
date <- date + 1
}
return(as.integer(format(date - 1, format="%d")))
}
调用为：
> date = as.Date("2011-02-23", "%Y-%m-%d")
> numberOfDays(date)
[1] 28
> date # date is unchanged
[1] "2011-02-23"