Re: [R] need to delete by time, not date

From: Clint Bowman <clint_at_ecy.wa.gov>
Date: Tue, 10 May 2011 08:14:34 -0700 (PDT)

You may be happy using:

strptime(paste(Date,Time,sep=" "),"%m/%d/%y %H:%M")$hour

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On Tue, 10 May 2011, Schatzi wrote:


> I have a matrix where one column has a date and another column has a time. I
> need to delete all times before 6am. I had combined the Date and Time column
> into DateTime.
>
> Mat1:
> Weight Date Time
> 7.6 04/28/11 09:03
> 8.4 04/29/11 03:11
> 8.6 04/29/11 05:32
> 8.6 04/29/11 09:53
> 1.4 05/01/11 19:52
>
> I tried just picking up the time:
>
> as.POSIXct(Mat1$Time, format = "%H:%M")
>
> but this assigns the time value today's date.
>
> The final matrix should look like:
> Weight Date Time
> 7.6 04/28/11 09:03
> 8.6 04/29/11 09:53
> 1.4 05/01/11 19:52
>
>
> -----
> In theory, practice and theory are the same. In practice, they are not - Albert Einstein
> --
> View this message in context: http://r.789695.n4.nabble.com/need-to-delete-by-time-not-date-tp3512162p3512162.html
> Sent from the R help mailing list archive at Nabble.com.
>
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>
______________________________________________ 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.
Received on Tue 10 May 2011 - 15:18:39 GMT

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