Hi, What's the best way to average dates? I though mean.POISXct would work fine but...> a[1] "2007-04-02 19:22:00 WEST"> b[1] "2007-03-17 16:23:00 WET"> class(a)[1] "POSIXt" "POSIXct"> class(b)[1] "POSIXt" "POSIXct"> mean(a,b)[1] "2007-04-02 19:22:00 WEST"> mean(b,a)[1] "2007-03-17 16:23:00 WET" ?! Thanks in advance for any advice, -- S?rgio Nunes
On Wed, 20 Jun 2007, S?rgio Nunes wrote:> Hi, > > What's the best way to average dates? > I though mean.POISXct would work fine but... > > > a > [1] "2007-04-02 19:22:00 WEST" > > b > [1] "2007-03-17 16:23:00 WET" > > class(a) > [1] "POSIXt" "POSIXct" > > class(b) > [1] "POSIXt" "POSIXct" > > mean(a,b) > [1] "2007-04-02 19:22:00 WEST" > > mean(b,a) > [1] "2007-03-17 16:23:00 WET"Would you usually call mean() in this way? mean(1, 2) mean(2, 1) Probably not... mean() expects a vector, try mean(c(a, b))! Z> ?! > > Thanks in advance for any advice, > -- > S?rgio Nunes > > ______________________________________________ > R-help at stat.math.ethz.ch 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. > >
You need to call 'mean.POSIXct' with a single vector:> a[1] "2007-01-01 12:00:00 GMT"> b[1] "2007-07-01 14:22:00 GMT"> mean(c(a,b))[1] "2007-04-02 01:11:00 GMT">On 6/20/07, Sérgio Nunes <snunes@gmail.com> wrote:> > Hi, > > What's the best way to average dates? > I though mean.POISXct would work fine but... > > > a > [1] "2007-04-02 19:22:00 WEST" > > b > [1] "2007-03-17 16:23:00 WET" > > class(a) > [1] "POSIXt" "POSIXct" > > class(b) > [1] "POSIXt" "POSIXct" > > mean(a,b) > [1] "2007-04-02 19:22:00 WEST" > > mean(b,a) > [1] "2007-03-17 16:23:00 WET" > > ?! > > Thanks in advance for any advice, > -- > Sérgio Nunes > > ______________________________________________ > R-help@stat.math.ethz.ch 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. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? [[alternative HTML version deleted]]