Jim's (and Petr's) solution wins....
-pd
> On 23 Jan 2020, at 10:56 , peter dalgaard <pda...@gmail.com> wrote:
>
> Here's an idea:
>
>> as.POSIXct(paste0("1963","-1-1"))+as.difftime(335,units="days") +
>> as.difftime(3, units="hours")
> [1] "1963-12-02 03:00:00 CET"
>
> However, 2 caveats
>
> (a) I think you need to subtract 1 from the DOY (1 should be Jan 1, right?)
> (b) Beware Daylight Savings time:
>
>> as.POSIXct(paste0("2019","-1-1"))+as.difftime(160,units="days") +
>> as.difftime(3, units="hours")
> [1] "2019-06-10 04:00:00 CEST"
>
> This can be worked around as follows:
>
>> tt <- as.POSIXct(paste0("2019","-1-1"))+as.difftime(160,units="days")
>> ttl <- as.POSIXlt(tt)
>> ttl$hour=0
>> ttl + as.difftime(3, units="hours")
> [1] "2019-06-10 03:00:00 CEST"
>
> ISOdate() and ISOdatetime() can also be used, again beware of time zones and
> DST. Also, ISOdate gives 12:00 GMT, whereas the POSIX stuff gives 0:00.
>
> -pd
>
>> On 23 Jan 2020, at 10:24 , Ogbos Okike <giftedlife2...@gmail.com> wrote:
>>
>> Dear Experts,
>> I have a data spanning 56 years from 1963 to 2018.
>> The datetime format is in DOY hour:
>> 1963 335 0
>> 1963 335 1
>> 1963 335 2
>> 1963 335 3
>> 1963 335 4
>> 1963 335 5
>> 1963 335 6
>> 1963 335 7
>> 1963 335 8
>> 1963 335 9
>> 1996 202 20
>> 1996 202 21
>> 1996 202 22
>> 1996 202 23
>> 1996 203 0
>> 1996 203 1
>> 1996 203 2
>> 1996 203 3
>> 2018 365 20
>> 2018 365 21
>> 2018 365 22
>> 2018 365 23
>> When I used:
>> as.Date(335,origin="1963-01-01"), for the first row, I got:
>> [1] "1963-12-02"
>> This is the format I want, though it is not yet complete. Time is missing.
>>
>> Again, I can't be doing this one after the other. I guess you have a
>> better way of handling this. I have spent some time trying to get it
>> right but I am really stuck. I would be most glad if you could spare
>> your busy time to help me again.
>>
>> Thank you very much for your usual kind assistance.
>>
>> Best regards
>> Ogbos
>>
>> ______________________________________________
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>> and provide commented, minimal, self-contained, reproducible code.
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd....@cbs.dk Priv: pda...@gmail.com
>
>
>
>
>
>
>
>
>
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd....@cbs.dk Priv: pda...@gmail.com
______________________________________________
R-help@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.
