[R] sorting by date

[Joshua Wiley]

Then just use order() for instance,

mydata <- read.table(textConnection("
20071130  information   info
20071031  information   info"))

closeAllConnections()

mydata[order(strptime(mydata$V1, format = "%Y%m%d")), ]

HTH,

Josh

On Mon, Aug 2, 2010 at 7:07 PM, Leigh E. Lommen
<leigh.lommen at courtesycorporation.com> wrote:
> a <- c( 20071031,20071130, 20071231)
> sort(a)
>
> Or if you want convert to date:
> sort(strptime(a, '%Y%m%d'))
>
> Okay, but what if you have information in the other columns?
>
>
>
> For example:
>
>
>
> 20071031  information   info
>
> 20071130  information   info
>
> 20071231  information   info
>
> Etc.
>
>
>
> Thanks.
>
> Leigh
>
>
>
> ________________________________
>
> From: Henrique Dallazuanna [mailto:wwwhsd at gmail.com]
> Sent: Monday, August 02, 2010 8:12 PM
> To: Leigh E. Lommen
> Cc: r-help at r-project.org
> Subject: Re: [R] sorting by date
>
>
>
> a <- c( 20071031,20071130, 20071231)
> sort(a)
>
> Or if you want convert to date:
> sort(strptime(a, '%Y%m%d'))
>
> On Mon, Aug 2, 2010 at 9:03 PM, Leigh E. Lommen <leigh.lommen at courtesycorporation.com> wrote:
>
> I am unsure how to sort a column by date if it is currently in the form:
>
> YYYYMMDD
>
>
>
> For example the months:
>
> 20071031
>
> 20071130
>
> 20071231
>
> Etc.
>
>
>
> Regards,
>
> Leigh
>
>
>       [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>
>
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/