Michael Weylandt wrote > > Can you provide a reproducible example? > Of course, Michael.
Consider the following time series: 11/2/2011 14:30 123.53 11/2/2011 15:00 123.78 11/2/2011 15:30 124.24 11/2/2011 16:00 124.2 11/2/2011 16:30 124.07 11/2/2011 17:00 123.91 11/2/2011 17:30 123.44 11/2/2011 18:00 123.0616 11/2/2011 18:30 123.06 11/2/2011 19:00 123.13 11/2/2011 19:30 123.745 11/2/2011 20:00 123.96 11/2/2011 20:30 123.99 11/2/2011 21:00 123.99 11/3/2011 14:30 124.3 11/3/2011 15:00 124.38 11/3/2011 15:30 124.67 11/3/2011 16:00 125.19 11/3/2011 16:30 124.9 11/3/2011 17:00 125.27 11/3/2011 17:30 125.5 11/3/2011 18:00 125.58 11/3/2011 18:30 125.91 11/3/2011 19:00 125.8 11/3/2011 19:30 125.83 11/3/2011 20:00 126.215 11/3/2011 20:30 126.25 11/3/2011 21:00 126.25 11/4/2011 14:30 124.901 11/4/2011 15:00 124.43 11/4/2011 15:30 124.4654 11/4/2011 16:00 124.46 11/4/2011 16:30 124.68 11/4/2011 17:00 124.86 11/4/2011 17:30 124.73 11/4/2011 18:00 125.22 11/4/2011 18:30 125.48 11/4/2011 19:00 125.5601 11/4/2011 19:30 125.4091 11/4/2011 20:00 125.15 11/4/2011 20:30 125.43 11/4/2011 21:00 125.481 11/7/2011 15:30 125.91 11/7/2011 16:00 125.29 11/7/2011 16:30 124.79 11/7/2011 17:00 124.77 11/7/2011 17:30 124.7 11/7/2011 18:00 124.37 11/7/2011 18:30 124.56 11/7/2011 19:00 124.86 11/7/2011 19:30 125.3 11/7/2011 20:00 125.59 11/7/2011 20:30 125.95 11/7/2011 21:00 125.73 11/7/2011 21:30 126.27 11/7/2011 22:00 126.26 11/8/2011 15:30 127.33 11/8/2011 16:00 126.37 11/8/2011 16:30 126.46 11/8/2011 17:00 126 11/8/2011 17:30 126.06 11/8/2011 18:00 126.2662 11/8/2011 18:30 126.23 11/8/2011 19:00 126.4499 11/8/2011 19:30 127.12 11/8/2011 20:00 127.48 11/8/2011 20:30 127.49 11/8/2011 21:00 127.69 11/8/2011 21:30 127.88 11/8/2011 22:00 127.88 11/9/2011 15:30 124.51 11/9/2011 16:00 124.42 11/9/2011 16:30 124.92 11/9/2011 17:00 125.18 11/9/2011 17:30 125.23 11/9/2011 18:00 124.81 11/9/2011 18:30 125.07 11/9/2011 19:00 124.61 11/9/2011 19:30 123.8869 11/9/2011 20:00 123.24 11/9/2011 20:30 123.3329 11/9/2011 21:00 123.6 11/9/2011 21:30 123.19 11/9/2011 22:00 123.161 The rownames are datas plus hour, the data column is the time series' value. -- View this message in context: http://r.789695.n4.nabble.com/How-to-sum-and-group-data-by-DATE-in-data-frame-tp903708p4630228.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.
