I noticed that when one tries to extend a time series (ts) object by a single period using window() actually two observations (NAs) are added. See below for an example. Does anyone know the reason for this behavior and how to avoid it? Thanks. FS> x<-ts(c(1,2,3)) > x1<- window(x, start(x), end(x) + 1, extend = TRUE) > x1Time Series: Start = 1 End = 5 Frequency = 1 [1] 1 2 3 NA NA
On Tue, 26 Apr 2005 11:52:00 -0400 Fernando Saldanha wrote:> I noticed that when one tries to extend a time series (ts) object by a > single period using window() actually two observations (NAs) are > added. See below for an example. Does anyone know the reason for this > behavior and how to avoid it?Yes: end(x) + 1 is not what you expect it to be. You can set equivalently end = 4 end = c(4, 1) to achieve what you want and you can compute one of those representations in various ways, e.g., tsp(x)[2] + 1. Z> Thanks. > > FS > > > x<-ts(c(1,2,3)) > > x1<- window(x, start(x), end(x) + 1, extend = TRUE) > > x1 > Time Series: > Start = 1 > End = 5 > Frequency = 1 > [1] 1 2 3 NA NA > > ______________________________________________ > 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 >
On 4/26/05, Fernando Saldanha <fsaldan1@gmail.com> wrote:> > I noticed that when one tries to extend a time series (ts) object by a > single period using window() actually two observations (NAs) are > added. See below for an example. Does anyone know the reason for this > behavior and how to avoid it? > > Thanks. > > FS > > > x<-ts(c(1,2,3)) > > x1<- window(x, start(x), end(x) + 1, extend = TRUE) > > x1 > Time Series: > Start = 1 > End = 5 > Frequency = 1 > [1] 1 2 3 NA NAAnother way to do it is: ts(c(x, NA), start = start(x), freq = frequency(x)) [[alternative HTML version deleted]]