Thank and sorry i should check this before asking the question. Andrija
On Thu, Dec 8, 2011 at 3:20 PM, R. Michael Weylandt < michael.weyla...@gmail.com> <michael.weyla...@gmail.com> wrote: > R FAQ 7.31 I'd imagine. (Floating point arithmetic and limitations thereof) > > Michael > > On Dec 8, 2011, at 9:15 AM, andrija djurovic <djandr...@gmail.com> wrote: > > > Hi all. I tried to calculate sum of deviations from the weighted mean > and i > > didn't get what i expected - 0. Here is an example: > > > >> wt <- c(10,25,38,22,5) > >> x <- 6:10 > >> wm <- weighted.mean(x,wt) > >> (x-wm)*wt > > [1] -18.70 -21.75 4.94 24.86 10.65 > >> sum((x-wm)*wt) > > [1] -1.24345e-14 > > > > With simple mean I got 0: > >> sum(x-mean(x)) > > [1] 0 > > > > Could someone explain me why we didn't get 0, with weighted mean, as it > is > > expected? > > Thanks in advance > > > > Andrija > > > > [[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. > [[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.
