前言:
微博参与话题 #给你四年时间你也学不会生信#
Built-in Constants | 内置常量
Usage
LETTERS: the 26 upper-case letters of the Roman alphabet;#26个大写拉丁字母
letters: the 26 lower-case letters of the Roman alphabet; #26个小写拉丁字母
month.abb: the three-letter abbreviations for the English month names; #英语月名的字母缩写
month.name: the English names for the months of the year; #一年中的月名
pi: the ratio of the circumference of a circle to its diameter.#圆周率：圆的周长与它的直径之比。
These are implemented as variables in the base namespace taking appropriate values.
Example | 例子
> month.name
[1] "January" "February" "March" "April" "May" "June" "July" "August"
[9] "September" "October" "November" "December"
> month.abb
[1] "Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"
> letters
[1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z"
> ## months in your current locale
> format(ISOdate(2000, 1:12, 1), "%B")
[1] "一月" "二月" "三月" "四月" "五月" "六月" "七月" "八月" "九月" "十月" "十一月"
[12] "十二月"
ISOdate | 日期
- Date-time Conversion Functions from Numeric Representations
从数字表示的日期转换函数
> format(ISOdate(2000, 1:12, 1), "%b")
[1] "1月" "2月" "3月" "4月" "5月" "6月" "7月" "8月" "9月" "10月" "11月" "12月"
> ISOdate(2000, 1:12, 1)
[1] "2000-01-01 12:00:00 GMT" "2000-02-01 12:00:00 GMT" "2000-03-01 12:00:00 GMT" "2000-04-01 12:00:00 GMT"
[5] "2000-05-01 12:00:00 GMT" "2000-06-01 12:00:00 GMT" "2000-07-01 12:00:00 GMT" "2000-08-01 12:00:00 GMT"
[9] "2000-09-01 12:00:00 GMT" "2000-10-01 12:00:00 GMT" "2000-11-01 12:00:00 GMT" "2000-12-01 12:00:00 GMT"
