Re: [R] hours() in 'chron': output != input

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Wed 20 Sep 2006 - 19:06:11 GMT

I think hours should have a comparison tolerance. Try:

   hours(x+1e-10)

as a workaround.

On 9/20/06, Glen A Sargeant <glen_sargeant@usgs.gov> wrote:
> I encountered surprising (to me, at least) behavior while using 'hours()'
> in package 'chron.' I will be grateful if someone can point out my error
> or provide an explanation and intuitive solution (I suppose I could
> convert chron to a character vector and use substring, but I deal mostly
> with newbies and kludgy approaches don't inspire much confidence).
>
> I used 2.3.0 to construct the dataframe below.
>
> 1) 'date.char' is a character vector
>
> 2) 'time.char' is a character vector
>
> 3) 'chron' was created by
> >chron(dates(date.char),times(time.char))
>
> 4) hours were extracted with
> >hours(chron).
>
> 5) Note that the hours used to construct 'chron' do not match the hours
> extracted with 'hours()' when minutes and seconds are "00:00."
>
> date.char time.char chron hour
> 1 09/20/06 00:00:00 (09/20/06 00:00:00) 0
> 2 09/20/06 01:00:00 (09/20/06 01:00:00) 0
> 3 09/20/06 02:00:00 (09/20/06 02:00:00) 2
> 4 09/20/06 03:00:00 (09/20/06 03:00:00) 3
> 5 09/20/06 04:00:00 (09/20/06 04:00:00) 3
> 6 09/20/06 05:00:00 (09/20/06 05:00:00) 5
> 7 09/20/06 06:00:00 (09/20/06 06:00:00) 6
> 8 09/20/06 07:00:00 (09/20/06 07:00:00) 6
> 9 09/20/06 08:00:00 (09/20/06 08:00:00) 8
> 10 09/20/06 09:00:00 (09/20/06 09:00:00) 9
> 11 09/20/06 10:00:00 (09/20/06 10:00:00) 9
> 12 09/20/06 11:00:00 (09/20/06 11:00:00) 11
> 13 09/20/06 12:00:00 (09/20/06 12:00:00) 12
> 14 09/20/06 13:00:00 (09/20/06 13:00:00) 12
> 15 09/20/06 14:00:00 (09/20/06 14:00:00) 14
> 16 09/20/06 15:00:00 (09/20/06 15:00:00) 15
> 17 09/20/06 16:00:00 (09/20/06 16:00:00) 15
> 18 09/20/06 17:00:00 (09/20/06 17:00:00) 17
> 19 09/20/06 18:00:00 (09/20/06 18:00:00) 18
> 20 09/20/06 19:00:00 (09/20/06 19:00:00) 18
> 21 09/20/06 20:00:00 (09/20/06 20:00:00) 20
> 22 09/20/06 21:00:00 (09/20/06 21:00:00) 21
> 23 09/20/06 22:00:00 (09/20/06 22:00:00) 21
> 24 09/20/06 23:00:00 (09/20/06 23:00:00) 23
>
> This behavior is problematic if one wants to extract hours and use them to
> group data.
>
> Regards,
>
> Glen Sargeant
>
> ______________________________________________
> R-help@stat.math.ethz.ch 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.
>



R-help@stat.math.ethz.ch 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 Thu Sep 21 05:10:56 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Wed 20 Sep 2006 - 19:30:05 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.