[R] Lubdridate: subset based on hour and minute

Joe Ceradini joeceradini at gmail.com
Mon Jan 2 21:27:37 CET 2017


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
>>
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>
> **********************
> "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
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>
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> "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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