Thanks for your reply Gabor. As I already have a dates column in my dataframe (in column row.names), is it possible to preserve this whilst still making a data set suitable for rollapply()?
Thanks, rcoder Gabor Grothendieck wrote: > > If its regular you can convert it to ts or zoo. > If its irregular convert it to zoo. There is no > reason to expect rollapply to work with objects > of other classes. Read ?ts and ?zoo. In > ts note the start and frequency arguments. > > > On Sat, Aug 2, 2008 at 7:50 AM, rcoder <[EMAIL PROTECTED]> wrote: >> >> Hi everyone, >> >> I have a data frame, with the following format: >> >> MatDate-> >> row.names ID1 ID2 ID3 >> 1 date1 >> 2 date1 >> 3 date3 >> etc >> >> but I cannot perform a rollapply() statement on the matrix without >> converting the matrix into a time series. >> i.e. MatTs<-ts(MatDate) > > Use the start and frequency arguments. See ?ts > >> >> Only then will my rollapply statement work: >> MatMin<-rollapply(MatTs, 2,by=2, min, na.rm=F) >> >> If I apply the rollapply() statement to the dataframe, I get the >> following >> error: Error: could not find function "rollapply" >> >> The problem is that when I convert the data.frame matrix into a time >> series >> matrix, I lose the dates in the row.names column. I just want to know if >> anyone could suggest a way to get around this problem, i.e. keep the >> row.names column in place, and use the rollapply() statement as above. >> >> Thanks, >> >> rcoder >> -- >> View this message in context: >> http://www.nabble.com/losing-row.names-in-matrix-operations-tp18788509p18788509.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. > > -- View this message in context: http://www.nabble.com/losing-row.names-in-matrix-operations-tp18788509p18789688.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
