Hello, I have a time series with intraday datas, sampled every 30'; I would need to aggregate them in this way: summing up all datas within a day.
I tried to use *aggregate(...)* function to get my goal, but it aggregates in wrong way (I did not understand how so far); what I need is like *sum(...)* function applied to datas within the same day. Thank you :) -- View this message in context: http://r.789695.n4.nabble.com/How-to-sum-and-group-data-by-DATE-in-data-frame-tp903708p4630119.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.