On Wed, 28 Mar 2007, Alfonso Sammassimo wrote: > Is there a way of aggregating 'zoo' daily data according to day of week? eg > all Thursdays
Sure, the easiest way will probably differ depending on the time stamp class. One example might be this: ## small example with Date index z <- read.zoo(file.path(.find.package("zoo"), "doc", "demo1.txt"), sep = "|", format = "%d %b %Y") ## visualization plot(z) ## aggregate along week days (via POSIXlt representation) aggregate(z, as.POSIXlt(time(z))$wday, mean) hth, Z > I came across the 'nextfri' function in the documentation but am unsure how > to change this so any day of week can be aggregated. > > I have used POSIX to arrange the data (not as 'zoo' series) according to day > of week, but am curious if I've missed if a similar option available with > zoo. > > Thank you for any help, > > Alf Sammassimo > Melbourne, Australia > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.