Hello Yen, You may find ?zapsmall helpful. If your algorithm expects 1-sum(x) to have a lower bound of zero, then also simply setting a cutoff point seems reasonable.
Josh On Tue, Jun 15, 2010 at 3:00 PM, Yen Lee <b88207...@ntu.edu.tw> wrote: > Hello, everyone, > > There's a problem about zero in R and I really need your help. > > > > I have a vector shown as x=c(0.1819711,0.4811463,0.1935151,0.1433675), > > The sum of this vector is shown as 1 in R, but when I type 1-sum(x), the > value is not zero, but -2.220446e-16. > > I can accept that this value is quite small and could be seen as zero, but > there would be a problem when it's not really zero but a negative value in > my algorithm. > > > > Therefore I would like to know that how could it be avoid. > > One way I think is to define the value 1-sum(x) as zero when it is smaller > than a particular value, but the particular value is not be set yet. > > I would like to know more about the definition of the shown zero in R. > > > > Thank you so much. > > > > Yen > > > [[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. > -- Joshua Wiley Ph.D. Student Health Psychology University of California, Los Angeles ______________________________________________ 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.
