Thank you, Gabor! This is a very elegant solution. But instead of general last day of month in the index, how can I have last day of each month as they are presented in "a", for example, not March 31, but March 27?
Regards, Sergey On Thu, Apr 8, 2010 at 17:27, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > Omit rep. You just want a <- zoo(1:9, ...). To get the last day of > the month you don`t need b since as.Date.yearmon will give it with the > argument frac = 1: > >> aggregate(a, as.Date(as.yearmon(time(a)), frac = 1), tail, 1) > 2009-03-31 2009-04-30 2009-05-31 2009-06-30 > 2 5 8 9 > > > On Thu, Apr 8, 2010 at 11:18 AM, Sergey Goriatchev <serg...@gmail.com> wrote: >> Hello, everyone >> >> I have the following problem: >> Say I have an irregular zoo timeseries like this: >> >> a <- zoo(rep(1:9), as.Date(c("2009-03-20", "2009-03-27", "2009-04-24", >> "2009-04-25", "2009-04-30", "2009-05-15", "2009-05-22", "2009-05-29", >> "2009-06-26"))) >> >> and I have regular zoo timeseries like this: >> >> b <- zoo(rep(1:4), as.Date(c("2009-03-31", "2009-04-30", "2009-05-31", >> "2009-06-30"))) >> >> >From "a" I need to extract those rows that hold values for the last >> day of each month (creating series "c"). Then I have to merge these >> values with "b", such that the result has the index of "c". >> >> How could I do this most efficiently? >> >> Thank you in advance! >> >> Best, >> Sergey >> >> -- >> Simplicity is the last step of art./Bruce Lee >> >> ______________________________________________ >> 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. >> > -- Simplicity is the last step of art./Bruce Lee The more you know, the more you know you don't know. /Myself I'm not young enough to know everything. /Oscar Wilde Experience is one thing you can't get for nothing. /Oscar Wilde When you are finished changing, you're finished. /Benjamin Franklin Luck is where preparation meets opportunity. /George Patten Kniven skärpes bara mot stenen. ______________________________________________ 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.