On Wed, Jul 21, 2010 at 6:59 PM, Joshua Wiley <jwiley.ps...@gmail.com> wrote: > Hello, > > I am using rollapply() from package zoo to use a function on unique > windows from a dataset. Because my dataset is not a multiple of my > window width, it matters which end I start at. Here is a simple > example, the result I want is 7.5 (i.e., start at the highest level of > my ordering variable). I thought that the argument ascending = FALSE > would do it, but it does not seem to have an effect. It seems like I > must be missing something simple. > > #Library and sample data > library(zoo) > mydata <- zoo(x = 6:8, order.by = 1:3) > > rollapply(data = mydata, width = 2, by = 2, > FUN = mean, ascending = TRUE, align = "left") > > #This gives the same results > rollapply(data = mydata, width = 2, by = 2, > FUN = mean, ascending = FALSE, align = "left") > >
ascending only specifies the order to pass each set of points but does not change the sets themselves. Try this: > rollapply(data = mydata[-1], width = 2, by = 2, FUN = mean) 2 7.5 ______________________________________________ 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.
