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

[Dimitri Liakhovitski]

Sorry for renewing the topoic. I thought it worked but now I've run
into a little problem:

 # My data frame with dates for week starts (Mondays)
y<-data.frame(week=seq(as.Date("2009-12-28"),
as.Date("2011-12-26"),by="week") )

# I have a vector of super bowl dates (including the future one for 2012):
sbwl.dates<-as.Date(c("2005-02-06","2006-02-05","2007-02-04","2008-02-03","2009-02-01","2010-02-07","2011-02-06","2012-02-05"))
I want to find the weeks in y that contain super bowl dates for
applicable years. I am trying:
sbwl.weeks<-findInterval(sbwl.dates, y$week)
sbwl.weeks<-sbwl.weeks[sbwl.weeks>0]
(sbwl.weeks)
> 6 58 105
y$flag<-0
y$flag[sbwl.weeks]<-1

6 and 58 are correct. But why am I getting 105 (the last row)?
Any way to fix it?
Thanks a lot!
Dimitri



On Tue, Aug 2, 2011 at 12:57 PM, Dimitri Liakhovitski
<dimitri.liakhovitski at gmail.com> wrote:
> 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
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> 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.
>>>
>>
>
>
>
> --
> Dimitri Liakhovitski
> marketfusionanalytics.com
>



-- 
Dimitri Liakhovitski
marketfusionanalytics.com