在 R 中转换日期

Converting date in R

我想将这些日期转换为“1995-01”、“1995-02”等格式

这是我的一些数据

              Date     Change
1     January-1995 0.01417476
2    February-1995 0.01427050
3       March-1995 0.01556348
4       April-1995 0.01644737
5         May-1995 0.01603727
6        June-1995 0.01627500
7        July-1995 0.01557800
8      August-1995 0.01429773
9   September-1995 0.01344300
10    October-1995 0.01334667
11   November-1995 0.01328429
12   December-1995 0.01345368
13    January-1996 0.01293091
14   February-1996 0.01301762
15      March-1996 0.01289048
16      April-1996 0.01268476
17        May-1996 0.01287364
18       June-1996 0.01253400
19       July-1996 0.01254591
20     August-1996 0.01271238
21  September-1996 0.01245700
22    October-1996 0.01201636
23   November-1996 0.01191300
24   December-1996 0.01195600

我试过了:

date <- as.Date(Data$Date,format="%B/%Y")

还有这个

date <- as.Date(paste0("01/", Data$Date),format = "%m/%Y")

但它只是return我

[1] NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

我卡住了!

最后一个选项可以修改为在我们 paste 当天包含 %d 日期。此外,在 format 中指定正确的分隔符和 %B-(完整的月份名称),其中 %m- 月份为十进制数)

as.Date(paste0("01/", Data$Date),format = "%d/%B-%Y")

或使用lubridate

library(lubridate)
my(Data$Date)
my("January-1995")
[1] "1995-01-01"

这是另一个基本 R 选项,但输出类型为 string(不是 Date

x <- c("January-1995", "February-1996")

paste0(
    gsub("\D", "", x),
    "-",
    sprintf("%02d", match(gsub("-.*", "", x), month.name))
)

这给出了

[1] "1995-01" "1996-02"