On 16 Feb 2006, at 23:17, Uwe Ligges wrote: > Barry Zajdlik wrote: > >> Hi All, >> >> An annoying but not critical problem I am having is that the variance >> of >> a vector of constants is reported as > 0. I imagine there is a simple >> workaround for the following but could not find it after having spent >> an >> embarrassing amount of time. >> >> In Splus: >> >> >>> x<-rep(0.02,10) >>> var(x) >>> 0 >> >> >> In R: >> >> x<-rep(0.02,10) >> var(x) >> 1.337451e-35 > > > Which version of R and which OS is this? I get 0 for both Linux and > Windows with R-2.2.1. > Anyway, 0.02 is not well representable and hence can be very well the > cause for such a numerical inaccuracy. > >> I assumed the problem had to do with machine precision and suitably >> modified .Machine$double.eps and .Machine$double.neg.eps which I >> thought >> would fix the problem but without success. Any pointers to a solution >> would be appreciated! > > Changing .Machine$double.eps does not help to calculate more accurate > ... > > Uwe Ligges > > >> Cheers, >> Barry Zajdlik >> >> ______________________________________________ >> [email protected] mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide! >> http://www.R-project.org/posting-guide.html > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > -- Jari Oksanen, Oulu, Finland
______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
