[datatable-help] problems with adding a DateTime column

[Chris Neff]

Try as.IDate around your strptime.  strptime returns POSIXlt which
isn't really amenable to data tables (or frames for that matter).  In
base R you would usually convert to POSIXct, but IDate is integer
based and made to be able to key on dates in data.tables.

On Thu, Mar 8, 2012 at 11:11 AM, Alexander Peterhansl
<APeterhansl at gaincapital.com> wrote:
> Dear Datatable-Help:
>
> I’m running R version 2.14.1 and data.table 1.7.10 (on Windows 7 and
> Linux).  On both systems I get a strange result in the following toy
> example:
>
>
>
> test <- data.table(A=c(1,2,3))
>
> test[,B:= c("2011-01-01","2011-01-02","2011-01-03")]
>
> test[,C:=
> strptime(c("2011-01-01","2011-01-02","2011-01-03"),format="%Y-%m-%d")]
>
> Output:
>
>       A          B       C
>
> [1,]   1 2011-01-01 0, 0, 0
>
> [2,]   2 2011-01-02 0, 0, 0
>
> [3,]   3 2011-01-03 0, 0, 0
>
>
>
> Columns A and B show the expected behavior.  Column C was supposed to simply
> convert the date strings into DateTime types.  Clearly this is not
> happening.
>
>
>
> Please help.
>
> Regards,
>
> Alex
>
>
>
>
>
>
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