I very appreciate for good comments and tip regarding my question. All postings are excellent to know when I am writing such expression in R. Thank you so much, and my question is completely resolved from all your postings.
On Sun, 2012-09-02 at 00:50 +0100, Rui Barradas wrote: > Em 02-09-2012 00:10, Jeff Newmiller escreveu: > > I disagree that this answer is "wrong". If you want a mathematically > > correct answer you are going to have to obtain it by applying intelligence > > to the algorithm in which this calculation occurred. > > Logarithms are the product of intelligence. > And the standard trick to make this sort of computation. > > x <- 1e3 > exp(x + log(0)) # zero > > x <- 1e300 > exp(x + log(0)) # zero > > Rui Barradas > > This is not a mailing list about numerical methods in general, so it > > probably isn't appropriate to pursue that conversation here. > > --------------------------------------------------------------------------- > > Jeff Newmiller The ..... ..... Go Live... > > DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... > > Live: OO#.. Dead: OO#.. Playing > > Research Engineer (Solar/Batteries O.O#. #.O#. with > > /Software/Embedded Controllers) .OO#. .OO#. rocks...1k > > --------------------------------------------------------------------------- > > Sent from my phone. Please excuse my brevity. > > > > CHEL HEE LEE <gnust...@gmail.com> wrote: > > > >> I have some trouble to deal the value of 'NaN'. For example, > >> > >>> exp(1e3) > >> [1] Inf > >>> exp(1e3)*0 > >> [1] NaN > >> > >> The correct answer should be 0 rather than NaN. I will very appreciate > >> if anyone can share some technique to get a correct answer. > >> > >> ______________________________________________ > >> 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. > > ______________________________________________ > > 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. > ______________________________________________ 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.
