Puting my 2cents: newDF<-data.frame(aggregate(X$PL_Pos, list(X$MyDate), sum)) colnames(newDF)<-c("MyDate","PL_Pos_SUM") good luck
milton On Fri, Aug 28, 2009 at 1:03 PM, jim holtman <jholt...@gmail.com> wrote: > Is this what you want: > > > aggregate(X$PL_Pos, list(X$MyDate), sum) > Group.1 x > 1 2009-08-03 174 > 2 2009-08-04 -26 > 3 2009-08-05 614 > 4 2009-08-06 318 > 5 2009-08-10 414 > 6 2009-08-11 -626 > 7 2009-08-12 544 > 8 2009-08-13 -106 > 9 2009-08-17 -146 > 10 2009-08-19 1004 > 11 2009-08-20 568 > 12 2009-08-24 -716 > 13 2009-08-25 -132 > 14 2009-08-26 8 > 15 2009-08-27 622 > > > You can fix up the column names. > > On Fri, Aug 28, 2009 at 12:37 PM, Mark Knecht<markkne...@gmail.com> wrote: > > Hi, > > I wonder if someone can suggest how to create a new data.frame Y > > from X where X$PL_Pos is summed by each unique X$MyDate. Y should end > > up with two (or more) columns Y$MyDate and Y$PL_Sum with its value > > being the cumsum of all the values in X for that date. - a 'daily > > cumsum'. > > > > Thanks, > > Mark > > > > > > TStoDate = function (TSDate) { > > X = strptime(TSDate + 19e6L, "%Y%m%d") > > return(as.Date(X)) > > } > > > > X = structure(list(EnDate = c(1090803, > > 1090804, 1090805, 1090806, 1090806, 1090810, 1090811, 1090812, > > 1090813, 1090817, 1090819, 1090820, 1090820, 1090824, 1090825, > > 1090825, 1090826, 1090826, 1090827, 1090827, 1090827), PL_Pos = c(174, > > -26, 614, 344, -26, 414, -626, 544, -106, -146, 1004, 344, 224, > > -716, -176, 44, 354, -346, -296, 564, 354)), .Names = c("EnDate", > "PL_Pos"), > > class = "data.frame", row.names = c("733", > > "734", "3631", "3641", "736", "2403", "2413", "3651", "3661", > > "3671", "3681", "3691", "1303", "3701", "1304", "1305", "2432", > > "1306", "3712", "1307", "4214")) > > > > X$MyDate = TStoDate(X$EnDate) > > > > X > > > > ______________________________________________ > > 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<http://www.r-project.org/posting-guide.html> > > and provide commented, minimal, self-contained, reproducible code. > > > > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem that you are trying to solve? > > ______________________________________________ > 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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ 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.