[R] add identifier column by row

[Sarah Goslee]

You can use rep() to create the Date column, and data.frame() to combine it.

For your simple example,

newdata <- data.frame(dat, Date=rep(1:3, each=2))

On Tue, May 21, 2013 at 4:16 PM, Ye Lin <yelin at lbl.gov> wrote:
> I want to add identifier column (Date) to a time series data frame. I want
> to name the "Date" column be from 1 to 30 every 1440 rows.
>
> Say I have a data like this (I simply my actual data here):
>
> $dat
>
> ID       Var
> 1          1
> 2          4
> 3         6
> 4         7
> 5          7
> 6          8
>
> How can I add identifier column (Date) from 1 to 3 every 2 rows and have
> output like this:
>
> ID       Var  Date
> 1          1      1
> 2          4     1
> 3         6      2
> 4         7      2
> 5          7     3
> 6          8      3


-- 
Sarah Goslee
http://www.functionaldiversity.org