[R] generating a sequence of seconds

[Erin Hodgess]

What I would like to do is to look at several days and determine activities
that happened at times on those days.  I don't really care which days, I
just care about what time.

Thank you!




On Tue, Aug 12, 2014 at 3:14 PM, William Dunlap <wdunlap at tibco.com> wrote:

> > What if I just want the seconds vector without the date, please?  Is
> there
> > a convenient way to create such a vector, please?
>
> Why do you want such a thing?  E.g., do you want it to print the time
> of day without the date?  Or are you trying to avoid numeric problems
> when you do regressions with the seconds-since-1970 numbers around
> 1414918800?  Or is there another problem you want solved?
>
> Note that the number of seconds in a day depends on the day and the
> time zone.  In US/Pacific time I get:
>
>   > length(seq(from=as.POSIXct("2014-08-12
> 00:00:00"),to=as.POSIXct("2014-08-12 23:59:59"), by="secs"))
>   [1] 86400
>   > length(seq(from=as.POSIXct("2014-03-09
> 00:00:00"),to=as.POSIXct("2014-03-09 23:59:59"), by="secs"))
>   [1] 82800
>   > length(seq(from=as.POSIXct("2014-11-02
> 00:00:00"),to=as.POSIXct("2014-11-02 23:59:59"), by="secs"))
>   [1] 90000
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
>
> On Tue, Aug 12, 2014 at 11:51 AM, Erin Hodgess <erinm.hodgess at gmail.com>
> wrote:
> > Hello!
> >
> > If I would like to generate a sequence of seconds for a date, I would do
> > the following:
> >
> > x <- seq(from=as.POSIXct(2014-08-12 00:00:00),to=as.POSIXct(2014-08-12
> > 23:59:59),by="secs")
> >
> > What if I just want the seconds vector without the date, please?  Is
> there
> > a convenient way to create such a vector, please?
> >
> > thanks,
> > Erin
> >
> >
> > --
> > Erin Hodgess
> > Associate Professor
> > Department of Mathematical and Statistics
> > University of Houston - Downtown
> > mailto: erinm.hodgess at gmail.com
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
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> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>



-- 
Erin Hodgess
Associate Professor
Department of Mathematical and Statistics
University of Houston - Downtown
mailto: erinm.hodgess at gmail.com

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