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. > ______________________________________________ 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.