R help - May 2013 - duplicate rows with new time series

Hey All,

I want to duplicate the records but add a new "timestamp" columns as
new
time series, but I dont know how to do that.

my dataset(dat1) looks like this:

No.          TimeStamp          Var1

1         2012-06-18 06:00:00    3
2         2012-06-18 06:06:00     4

I use this code to do duplication:

dat1[rep(1:nrow(dat1),each=3),]

But I dont know how to change the timeStamp. I would like the final output
be sth like this:

No.          TimeStamp          Var1

1         2012-06-18 06:00:00    3
2         2012-06-18 06:02:00    3
3         2012-06-18 06:04:00     3
4         2012-06-18 06:06:00     4
5         2012-06-18 06:08:00     4
6         2012-06-18 06:10:00     4

So basically the old time interval is 6 min, but the new ones I would like
to have is 2 min.


Thanks,

	[[alternative HTML version deleted]]

On Thu, May 9, 2013 at 7:24 PM, Ye Lin <yelin at lbl.gov>
wrote:
> Hey All,
>
> I want to duplicate the records but add a new "timestamp" columns
as new
> time series, but I dont know how to do that.
>
> my dataset(dat1) looks like this:
>
> No.          TimeStamp          Var1
>
> 1         2012-06-18 06:00:00    3
> 2         2012-06-18 06:06:00     4
>
> I use this code to do duplication:
>
> dat1[rep(1:nrow(dat1),each=3),]
>
> But I dont know how to change the timeStamp. I would like the final output
> be sth like this:
>
> No.          TimeStamp          Var1
>
> 1         2012-06-18 06:00:00    3
> 2         2012-06-18 06:02:00    3
> 3         2012-06-18 06:04:00     3
> 4         2012-06-18 06:06:00     4
> 5         2012-06-18 06:08:00     4
> 6         2012-06-18 06:10:00     4
>
> So basically the old time interval is 6 min, but the new ones I would like
> to have is 2 min.
Assuming dat2 is the result of the line of R code above that does the
replication and that TimeStamp is of POSIXct class try this:

    dat2$TimeStamp <- dat2$TimeStamp + seq(0, 4, 2))

--
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com