[R] Lubdridate: subset based on hour and minute

[Joe Ceradini]

Ahh, that makes more sense now. Thanks again.

On Mon, Jan 2, 2017 at 1:44 PM, Roy Mendelssohn - NOAA Federal <
roy.mendelssohn at noaa.gov> wrote:

> The trick is to realize times are stored internally in a special format,
> though they can be displayed in several ways based on the internal
> representation.  The trick in doing comparison with times is to make
> certain what you are comparing with has also been put into the same
> internal time format.  This should make clear the basis for the logical
> tests:
>
> > as.numeric(test)
> [1] 34200 36000 37800 39600
> >
> > as.numeric(hm("10:00"))
> [1] 36000
> >
>
> -Roy
>
>
> > On Jan 2, 2017, at 12:39 PM, Joe Ceradini <joeceradini at gmail.com> wrote:
> >
> > Bingo! Thanks! I somehow couldn't find an example like that via google.
> >
> > Joe
> >
> > On Mon, Jan 2, 2017 at 1:35 PM, Roy Mendelssohn - NOAA Federal
> > <roy.mendelssohn at noaa.gov> wrote:
> >>> test > hm("10:00")
> >> [1] FALSE FALSE  TRUE  TRUE
> >>> test[test > hm("10:00")]
> >> [1] "10H 30M 0S" "11H 0M 0S"
> >>
> >> -Roy
> >>
> >>
> >>> On Jan 2, 2017, at 12:27 PM, Joe Ceradini <joeceradini at gmail.com>
> wrote:
> >>>
> >>> Thanks for the reply Roy!
> >>>
> >>> Perhaps you're showing me the way and I'm missing it - how would I
> >>> subset to only 1030 and 1100, excluding 1000? It seems I would need to
> >>> say, give me all time greater than 10:00, but the hours and minutes
> >>> are in separate slots, which is throwing me off.
> >>>
> >>> Thanks again.
> >>>
> >>> On Mon, Jan 2, 2017 at 1:13 PM, Roy Mendelssohn - NOAA Federal
> >>> <roy.mendelssohn at noaa.gov> wrote:
> >>>> Hi Joe:
> >>>>
> >>>> See below.
> >>>>> On Jan 2, 2017, at 12:01 PM, Joe Ceradini <joeceradini at gmail.com>
> wrote:
> >>>>>
> >>>>> Hi folks,
> >>>>>
> >>>>> I must be missing something obvious/painfully simple here....
> >>>>>
> >>>>> How do I subset a time vector based on hours AND minutes? So, in this
> >>>>> example, I want all time greater than 10:00, i.e., 10:30 and 11:00.
> >>>>> I'm working with lubridate which separates the hours and minutes into
> >>>>> separate slots.
> >>>>>
> >>>>> require(lubridate)
> >>>>>
> >>>>> test <- hm(c("9:30", "10:00", "10:30", "11:00"))
> >>>>> test
> >>>>> [1] "9H 30M 0S"  "10H 0M 0S"  "10H 30M 0S" "11H 0M 0S"
> >>>>>
> >>>>> This gets 11 but not 1030
> >>>>> test[test at hour > 10]
> >>>>> [1] "11H 0M 0S"
> >>>>>
> >>>>> This gets 1030 but not 11
> >>>>> test[test at hour > 9 & test at minute > 0]
> >>>>> [1] "10H 30M 0S"
> >>>>
> >>>> test[test at hour > 9]
> >>>> [1] "10H 0M 0S"  "10H 30M 0S" "11H 0M 0S"
> >>>>
> >>>>
> >>>> You are using a logical "and" in your test - so the condition
> "test at minute > 0" isn't met for 11:00 and therefore it doesn't show up.
> as both conditions must be met  You could also do:
> >>>>
> >>>>> test[test at hour >= 10]
> >>>> [1] "10H 0M 0S"  "10H 30M 0S" "11H 0M 0S"
> >>>>
> >>>> -HTH,
> >>>>
> >>>> Roy
> >>>>
> >>>>>
> >>>>> Thanks and happy new year!
> >>>>> Joe
> >>>>>
> >>>>> ______________________________________________
> >>>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>>>> 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.
> >>>>
> >>>> **********************
> >>>> "The contents of this message do not reflect any position of the U.S.
> Government or NOAA."
> >>>> **********************
> >>>> Roy Mendelssohn
> >>>> Supervisory Operations Research Analyst
> >>>> NOAA/NMFS
> >>>> Environmental Research Division
> >>>> Southwest Fisheries Science Center
> >>>> ***Note new street address***
> >>>> 110 McAllister Way
> >>>> Santa Cruz, CA 95060
> >>>> Phone: (831)-420-3666
> >>>> Fax: (831) 420-3980
> >>>> e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/
> >>>>
> >>>> "Old age and treachery will overcome youth and skill."
> >>>> "From those who have been given much, much will be expected"
> >>>> "the arc of the moral universe is long, but it bends toward justice"
> -MLK Jr.
> >>>>
> >>>
> >>>
> >>>
> >>> --
> >>> Cooperative Fish and Wildlife Research Unit
> >>> Zoology and Physiology Dept.
> >>> University of Wyoming
> >>> JoeCeradini at gmail.com / 914.707.8506
> >>> wyocoopunit.org
> >>
> >> **********************
> >> "The contents of this message do not reflect any position of the U.S.
> Government or NOAA."
> >> **********************
> >> Roy Mendelssohn
> >> Supervisory Operations Research Analyst
> >> NOAA/NMFS
> >> Environmental Research Division
> >> Southwest Fisheries Science Center
> >> ***Note new street address***
> >> 110 McAllister Way
> >> Santa Cruz, CA 95060
> >> Phone: (831)-420-3666
> >> Fax: (831) 420-3980
> >> e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/
> >>
> >> "Old age and treachery will overcome youth and skill."
> >> "From those who have been given much, much will be expected"
> >> "the arc of the moral universe is long, but it bends toward justice"
> -MLK Jr.
> >>
> >
> >
> >
> > --
> > Cooperative Fish and Wildlife Research Unit
> > Zoology and Physiology Dept.
> > University of Wyoming
> > JoeCeradini at gmail.com / 914.707.8506
> > wyocoopunit.org
>
> **********************
> "The contents of this message do not reflect any position of the U.S.
> Government or NOAA."
> **********************
> Roy Mendelssohn
> Supervisory Operations Research Analyst
> NOAA/NMFS
> Environmental Research Division
> Southwest Fisheries Science Center
> ***Note new street address***
> 110 McAllister Way
> Santa Cruz, CA 95060
> Phone: (831)-420-3666
> Fax: (831) 420-3980
> e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/
>
> "Old age and treachery will overcome youth and skill."
> "From those who have been given much, much will be expected"
> "the arc of the moral universe is long, but it bends toward justice" -MLK
> Jr.
>
>


-- 
Cooperative Fish and Wildlife Research Unit
Zoology and Physiology Dept.
University of Wyoming
JoeCeradini at gmail.com / 914.707.8506
wyocoopunit.org

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