There is a one line nextfri function defined in the zoo-quickref vignette and replacing 5 with 1 in its definition will give you next Monday. The prior Monday is 7 days before that so take the closest of the two. See R News 4/1 for more about dates.
On Wed, May 13, 2009 at 4:23 PM, myshare <mrap...@gmail.com> wrote: > hi, > > I have a and data frame with date-column and some other columns. > My first question is what is the fastest way to get the index of an > array if I know the value f.e > >> x = c(4,5,6,7,8) > > so i know the value is 6.. i.e. the index is 3. What I currently do is > loop over the array, I was thinking if there > is faster more direct way. > The next one...is I have a data frame one of the columns is Date based > (stored as string), as you may be guessed > I have the date and I want to find the index ;), but here is one more > complication. > The dates are not sequential, but only dates when the day is Mon-Fri > i.e. for Sat and Sun i don't store information. > > So I have first convert the date I have into the closest Monday. > Let me give you one example. Let say I have the date 2000/01/01 (Sat), > now to be able to find any information I have to find the nearest > Monday in this case it is 2000/01/03 (Mon).. > So now that I have this new date I can find the index of the element > in the array where it is stored and from this I can get the real data > I need. > In short conversation is from Data ==> nearest Monday ==> index of the > element in the array where it is stored. > > thank you very much > > ______________________________________________ > R-help@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. > ______________________________________________ R-help@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.
