Message-ID: <Pine.LNX.4.61.0512121308520.18605@gannet.stats>
Date: 2005-12-12T13:09:12Z
From: Brian Ripley
Subject: question about date's
In-Reply-To: <0IRD00146WL6JO@mail.fudan.edu.cn>
On Mon, 12 Dec 2005, ronggui wrote:
>> x<-as.Date(c("2005-07-01", "2005-07-02","2005-07-03","2005-07-04","2005-07-05"))
>> weekdays(x)
> [1] "??????" "??????" "??????" "??????" "??????"
>
>> months(x)
> [1] "????" "????" "????" "????" "????"
He asked for week numbers. That's nothing like as easy, as it is not
well-defined. But
> strftime(as.POSIXlt(x), "%U")
[1] "26" "26" "27" "27" "27"
is one possibility ("%W" is another). This approach will do the other
requests just as easily.
> ======= 2005-12-12 20:17:38 ????????????????=======
>
>> Thanks!
>> That solves my problem for year numbers and month numbers
>> Any idea how to do this for week numbers?
>>
>> Regards,
>> Richard
>>
>> On 12/12/05, ronggui <042045003 at fudan.edu.cn> wrote:
>>> This is one way to do it.
>>>> x<-c("2005-07-01", "2005-07-02","2005-07-03","2005-07-04","2005-07-05")
>>>> x
>>> [1] "2005-07-01" "2005-07-02" "2005-07-03" "2005-07-04" "2005-07-05"
>>>> substr(x,1,4)
>>> [1] "2005" "2005" "2005" "2005" "2005"
>>>> substr(x,6,7)
>>> [1] "07" "07" "07" "07" "07"
>>>> substr(x,9,10)
>>> [1] "01" "02" "03" "04" "05"
>>>>
>>>
>>>
>>> ======= 2005-12-12 20:06:00 ????????????????=======
>>>
>>>> Hi,
>>>>
>>>> Given a frame with calendar date's:
>>>>
>>>> "2005-07-01", "2005-07-02","2005-07-03","2005-07-04","2005-07-05",etc.
>>>>
>>>> I want to extract the following from these dates:
>>>>
>>>> week number
>>>> month number
>>>> year number
>>>>
>>>> Any ideas how to accomplish this?
>>>>
>>>> Many thanks.
>>>>
>>>> Regards,
>>>> Richard
>>>>
>>>> ______________________________________________
>>>> R-help at stat.math.ethz.ch mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>>>
>>> = = = = = = = = = = = = = = = = = = = =
>>>
>>>
>>>
>>>
>>>
>>> 2005-12-12
>>>
>>> ------
>>> Deparment of Sociology
>>> Fudan University
>>>
>>> My new mail addres is ronggui.huang at gmail.com
>>> Blog:http://sociology.yculblog.com
>>>
>
> = = = = = = = = = = = = = = = = = = = =
>
>
>
>
>
> 2005-12-12
>
> ------
> Deparment of Sociology
> Fudan University
>
> My new mail addres is ronggui.huang at gmail.com
> Blog:http://sociology.yculblog.com
>
>
--
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