R help - Jun 2013 - Time of day

Is there a simple way to obtain the time of day in R? I want the time of
day for computational purposes, not for display. I want to be able to
create code like the following:

if (time_of_day >= 22:00 & time_of_day <= 06:00) then X otherwise Y

I realize I could parse a date/time object and extract the time, but
hopefully other people have already done this, or there is a
straightforward representation of time of day in R that I  have not been
able to find in the documentation.

Thanks.

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On 25/06/2013 06:59, Rguy wrote:
> Is there a simple way to obtain the time of day in R? I want the time of
> day for computational purposes, not for display. I want to be able to
> create code like the following:
>
> if (time_of_day >= 22:00 & time_of_day <= 06:00) then X otherwise
Y
which will not parse and in any case there are no such times.
> I realize I could parse a date/time object and extract the time, but
> hopefully other people have already done this, or there is a
> straightforward representation of time of day in R that I  have not been
> able to find in the documentation.
 > t <- Sys.time()
 > tt <- format(t, "%H:%M")
 > tt <= "22:00" && tt >= "06:00"
[1] TRUE

Note the use of && not &.
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
PLEASE do: no HTML mail ....



-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

On Tue, 25 Jun 2013, Rguy <rguy at 123mail.org> writes:
> Is there a simple way to obtain the time of day in R? I want the time of
> day for computational purposes, not for display. I want to be able to
> create code like the following:
>
> if (time_of_day >= 22:00 & time_of_day <= 06:00) then X otherwise
Y
                     ^^^^^                  ^^^^^
this will not work: the times need to be something that R understands,
eg, numeric values such as 2200 or character values such as "22:00"
>
> I realize I could parse a date/time object and extract the time, but
> hopefully other people have already done this, or there is a
> straightforward representation of time of day in R that I  have not been
> able to find in the documentation.
strftime(Sys.time(), "%H:%M")

-- 
Enrico Schumann
Lucerne, Switzerland
http://enricoschumann.net