Hello Gabor, thanks for your reply. Please excuse the insufficient description of my problem. I hope this one is better:
#Importing my data works basically like this dts <- dates(c("19700201","19700201","19700201","19700202","19700202"),format="ymd") tms <- times(paste(c("21:00", "22:00", "23:00","00:00", "01:00"),0,sep=":"),format="h:m:s") x <- chron(dates=dts,times=tms) z <- zoo(c(174.055,174.067,174.076,174.085,174.091),x) #Because I need daily values I run: z <- aggregate(z,trunc,mean) #And because I deal with different data sets and need to sum them up I run: m <- merge(z,z) When R executes merge() I get the following error message: "Fehler in matrix(unlist(lapply(dots, origin)), nrow = 3) : Versuch ein Attribut von NULL zu setzen" (Sorry that it's German. It says something like 'Error... Try to set attribute NULL') It's curious that there is no error when I first run merge() and than aggregate(), but this is not possible due to the rest of the programm. So why is merging not possible? Thanks in advance, gunnar R version 2.9.1 (Debian Lenny, XFCE 4.4, EMACS 22.2.1, ESS 5.3.8) -- View this message in context: http://www.nabble.com/zoo%3A-merging-aggregated-zoo-objects-fails-tp25633345p25643639.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.