Ok, so you may be right, but I do not understand why ;) The commands you suggested are applied to temp_plot, where temp_plot is a 'zoo' object as follows (there is actually something strange in here, if I just want to see the whole object I do not get the warning message that I got when selecting a sample):
temp_plot[1:10] 2008-01-02 2008-01-03 2008-01-04 2008-01-07 2008-01-08 2008-01-09 2008-01-10 48608 46686 55216 59268 50967 55067 57783 2008-01-11 2008-01-14 2008-01-15 60021 61480 63853 Warning message: In zoo(rval[i], x.index[i]) : some methods for “zoo” objects do not work if the index entries in ‘order.by’ are not unique First command: > temp_plot[duplicated(time(temp_plot))] Data: numeric(0) Index: character(0) Warning message: In zoo(rval[i], x.index[i]) : some methods for “zoo” objects do not work if the index entries in ‘order.by’ are not unique Second command table(time(temp_plot)) , , hour = 0, mday = 23, mon = 7, year = 110, wday = 2, yday = 1, isdst = 0 min sec 0 0 0 , , hour = 0, mday = 24, mon = 7, year = 110, wday = 2, yday = 1, isdst = 0 min sec 0 0 0 , , hour = 0, mday = 25, mon = 7, year = 110, wday = 2, yday = 1, isdst = 0 min sec 0 0 0 Third command: aggregate(temp_plot,identity,length) Error: length(time(x)) == length(by[[1]]) is not TRUE Well, I believe there is something indeed going on here! If I understood correctly, the second command tells me that is not able to recognize in the correct way the year (and most likely all the rest) while the third indicates a mismatch in the dimensions. Marco -- View this message in context: http://r.789695.n4.nabble.com/Chron-object-in-time-series-plot-tp3002285p3015182.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.