Mean of dates
On 24 April 2015 at 13:47, Jue Lin-Ye <jl.iccp at gmail.com> wrote:
On 24 April 2015 at 12:59, Achim Zeileis <Achim.Zeileis at 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
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