On 24 April 2015 at 13:47, Jue Lin-Ye <jl.i...@gmail.com> wrote: > > > On 24 April 2015 at 12:59, Achim Zeileis <achim.zeil...@uibk.ac.at> wrote: > >> >> >> On Fri, 24 Apr 2015, Jue Lin-Ye wrote: >> >> Dear fellow R-help members, >>> >>> If my data is >>> >>> YYYY MM DD HH >>> 2015 04 24 01 >>> 2015 04 24 02 >>> 2015 04 24 06 >>> >>> Where >>> >>> YYYY: year >>> MM:month >>> DD:day >>> HH: hour >>> >>> How could I calculate the mean of the ISOdatetime(YYYY,MM,DD,HH,0,0) of >>> these? >>> >> >> With the mean() method? On my machine: >> >> R> mean(ISOdatetime(YYYY,MM,DD,HH,0,0)) >> [1] "2015-04-24 03:00:00 CEST" >> >> > Hi! Maybe the problem is when I try to create the vector that I am > looking for. Please check this code out. > > > X_season1<-matrix(c(2015, 04, 24, 01, 2015 ,04, 24, 02, > 2015 ,04 ,24 ,03 ,2015 ,04 ,24 ,05, > 2015, 04, 24 ,06 ,2015, 04 ,24 > ,10),3,8,byrow=T);colnames(X_season1)<-c("AAi","MMi","DDi","HHi","AAf","MMf","DDf","HHf") > time2<-NULL > for(i5 in 1:nrow(X_season1)){ > time2[i5]<-mean( > > as.Date(c(ISOdatetime(X_season1[i5,"AAi"],X_season1[i5,"MMi"],X_season1[i5,"DDi"],X_season1[i5,"HHi"],0,0), > > ISOdatetime(X_season1[i5,"AAf"],X_season1[i5,"MMf"],X_season1[i5,"DDf"],X_season1[i5,"HHf"],0,0)), > format="%YYYY-%mm-%dd %H:%m:%s"),trim=0)} > > Thanks! > > Dear Dr. Zeileis,
Here is the solution that I finally came up with, I hope you agree with it. From your suggestion, I saw that the problem was the creation of the vector. It needed to be numeric. So I calculate the difftime from each date to a reference date (1990/01/01 00:00:00). The units is "hours". I obtain a vector of difference numbers. Then I add these numbers, transformed into seconds, to the reference date. Thank you so much for your help! Best regards, Jue > >> hth, >> Z >> >> Note: I set minutes and seconds to 0, as I don't have data for them. >>> >>> ?Thank you in advance!? >>> >>> -- >>> Jue Lin-Ye >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> 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. >> >> > > > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.