[R] identifying weeks (dates) that certain days (dates) fall into

[Dimitri Liakhovitski]

Thanks a lot, everyone!
Dimitri

On Tue, Aug 2, 2011 at 12:34 PM, Dennis Murphy <djmuser at gmail.com> wrote:
> Hi:
>
> You could try the lubridate package:
>
> library(lubridate)
> week(weekly$week)
> week(july4)
> [1] 27 27
>
>> week
> function (x)
> yday(x)%/%7 + 1
> <environment: namespace:lubridate>
>
> which is essentially Gabor's code :)
>
> HTH,
> Dennis
>
> On Tue, Aug 2, 2011 at 7:36 AM, Dimitri Liakhovitski
> <dimitri.liakhovitski at gmail.com> wrote:
>> Hello!
>>
>> I have dates for the beginning of each week, e.g.:
>> weekly<-data.frame(week=seq(as.Date("2010-04-01"),
>> as.Date("2011-12-26"),by="week"))
>> week  # each week starts on a Monday
>>
>> I also have a vector of dates I am interested in, e.g.:
>> july4<-as.Date(c("2010-07-04","2011-07-04"))
>>
>> I would like to flag the weeks in my weekly$week that contain those 2
>> individual dates.
>> I can only think of a very clumsy way of doing it:
>>
>> myrows<-c(which(weekly$week==weekly$week[weekly$week>july4[1]][1]-7),
>>        which(weekly$week==weekly$week[weekly$week>july4[2]][1]-7))
>> weekly$flag<-0
>> weekly$flag[myrows]<-1
>>
>> It's clumsy - because actually, my vector of dates of interest (july4
>> above) is much longer.
>> Is there maybe a more elegant way of doing it?
>> Thank you!
>> --
>> Dimitri Liakhovitski
>> marketfusionanalytics.com
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>



-- 
Dimitri Liakhovitski
marketfusionanalytics.com