正在转换R中的日期

Question

我想将这些日期转换为这种格式"1995-01"1995-02"；，等

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

我试过这个：

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

和这个

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

但它只是把还给我

[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

我被卡住了！

Answer 1

最后一个选项可以修改为包括当天的%d，当我们在当天为paste时。此外，在format中，指定正确的分隔符和%B-(完整月份名称(，其中作为%m-月份作为十进制数字(

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"

Answer 2

这是另一个基本R选项，但输出类型为string(而非Date(

x <- c("January-1995", "February-1996")
paste0(
gsub("\D", "", x),
"-",
sprintf("%02d", match(gsub("-.*", "", x), month.name))
)

它给出

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