我的数据如下：
Date department_id position_id totala Weekday start_Time Date Month Year
7/12/2014 7487 126476 218.39 5 956 12 7 2014
7/7/2014 7487 126476 270.28 7 855 7 7 2014
7/8/2014 7487 126476 247.83 1 810 8 7 2014
7/9/2014 7487 126476 191.16 2 959 9 7 2014
7/9/2014 7487 126476 191.16 2 627 9 7 2014
........
当我尝试将其转换为时间序列数据时，它会给我这个错误：
Error in as.POSIXlt.character(x, tz, ...) :
character string is not in a standard unambiguous format
str (ant):
'data.frame': 29 obs. of 5 variables:
**$ Date : Factor w/ 12 levels "6/29/2014","6/30/2014",..: 5 10 11 12 12 4 9 8 7 3** ...
$ department_id: int 7487 7487 7487 7487 7487 7487 7487 7487 7487 7487 ...
$ position_id : int 126476 126476 126476 126476 126476 126476 126476 126476 126476 126476 ...
$ totala : num 218 270 248 191 191 ...
$ start_Time : int 956 855 810 959 627 864 630 742 948 623 ...
答案 0 :(得分：1)
mydf = read.table(header=T, text="
+ Date department_id position_id totala Weekday start_Time Date Month Year
+ 7/12/2014 7487 126476 218.39 5 956 12 7 2014
+ 7/7/2014 7487 126476 270.28 7 855 7 7 2014
+ 7/8/2014 7487 126476 247.83 1 810 8 7 2014
+ 7/9/2014 7487 126476 191.16 2 959 9 7 2014
+ 7/9/2014 7487 126476 191.16 2 627 9 7 2014
+ ")
>
> mydf
Date department_id position_id totala Weekday start_Time Date.1 Month
1 7/12/2014 7487 126476 218.39 5 956 12 7
2 7/7/2014 7487 126476 270.28 7 855 7 7
3 7/8/2014 7487 126476 247.83 1 810 8 7
4 7/9/2014 7487 126476 191.16 2 959 9 7
5 7/9/2014 7487 126476 191.16 2 627 9 7
Year
1 2014
2 2014
3 2014
4 2014
5 2014
>
>
> str(mydf)
'data.frame': 5 obs. of 9 variables:
$ Date : Factor w/ 4 levels "7/12/2014","7/7/2014",..: 1 2 3 4 4
$ department_id: int 7487 7487 7487 7487 7487
$ position_id : int 126476 126476 126476 126476 126476
$ totala : num 218 270 248 191 191
$ Weekday : int 5 7 1 2 2
$ start_Time : int 956 855 810 959 627
$ Date.1 : int 12 7 8 9 9
$ Month : int 7 7 7 7 7
$ Year : int 2014 2014 2014 2014 2014
>
>
> mydf$Date = as.Date(mydf$Date, format="%m/%d/%Y")
>
> mydf
Date department_id position_id totala Weekday start_Time Date.1 Month Year
1 2014-07-12 7487 126476 218.39 5 956 12 7 2014
2 2014-07-07 7487 126476 270.28 7 855 7 7 2014
3 2014-07-08 7487 126476 247.83 1 810 8 7 2014
4 2014-07-09 7487 126476 191.16 2 959 9 7 2014
5 2014-07-09 7487 126476 191.16 2 627 9 7 2014
> str(mydf)
'data.frame': 5 obs. of 9 variables:
$ Date : Date, format: "2014-07-12" "2014-07-07" "2014-07-08" "2014-07-09" ...
$ department_id: int 7487 7487 7487 7487 7487
$ position_id : int 126476 126476 126476 126476 126476
$ totala : num 218 270 248 191 191
$ Weekday : int 5 7 1 2 2
$ start_Time : int 956 855 810 959 627
$ Date.1 : int 12 7 8 9 9
$ Month : int 7 7 7 7 7
$ Year : int 2014 2014 2014 2014 2014
>