On Tue, Jul 13, 2010 at 5:27 PM, Gavin Simpson <gavin.simp...@ucl.ac.uk>wrote:
> On Tue, 2010-07-13 at 17:13 +0530, sayan dasgupta wrote: > > Hi folks, > > > > I am confused whether the following is a bug or it is fine > > > > Here is the explanation > > > > a <- zoo(c(NA,1:9),1:10) > > > > Now If I do > > > > rollapply(a,FUN=mean,width=3,align="right") > > mean() has argument na.rm which defaults to FALSE. As such, if NA are in > the computation the mean is undefined and the answer will be NA. If you > pass na.rm = TRUE to rollapply, mean ignores the NA and works on the > remaining values: > > > rollapply(a,FUN=mean,width=3,align="right", na.rm = TRUE) > 3 4 5 6 7 8 9 10 > 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 > This is fine but the problem is logically when you are doing rollapply only the first 2 values should be NA but suppose for index 10 as I have mentioned the rollapply should be a mean of b9, 8 ,7 and there is no NA here. So it should not return NA > > HTH > > G > > > > > I get > > > rollapply(a,FUN=mean,width=3,align="right") > > 3 4 5 6 7 8 9 10 > > NA NA NA NA NA NA NA NA > > > > But I shouldn't be getting NA right ? i.e for index 10 I should get > > (1/3)*(9+8+7) > > > > Similarly > > > > > rollapply(a,FUN=mean,width=3) > > 2 3 4 5 6 7 8 9 > > NA NA NA NA NA NA NA NA > > > > > > Zoo version : > > > > > installed.packages()["zoo","Version"] > > [1] "1.6-3" > > > > > > > > > My machine details > > > > > sessionInfo() > > R version 2.10.1 (2009-12-14) > > i386-pc-intel32 > > > > locale: > > [1] LC_COLLATE=English_India.1252 LC_CTYPE=English_India.1252 > > LC_MONETARY=English_India.1252 LC_NUMERIC=C > > [5] LC_TIME=English_India.1252 > > > > attached base packages: > > [1] stats graphics grDevices datasets utils methods base > > > > other attached packages: > > [1] zoo_1.6-3 rcom_2.2-1 rscproxy_1.3-1 Revobase_3.2.0 > > > > loaded via a namespace (and not attached): > > [1] grid_2.10.1 lattice_0.18-3 tools_2.10.1 > > > > > > > [[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. > > -- > %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% > Dr. Gavin Simpson [t] +44 (0)20 7679 0522 > ECRC, UCL Geography, [f] +44 (0)20 7679 0565 > Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk > Gower Street, London [w] > http://www.ucl.ac.uk/~ucfagls/<http://www.ucl.ac.uk/%7Eucfagls/> > UK. WC1E 6BT. [w] http://www.freshwaters.org.uk > %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% > > [[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.
