Dear Friends I am facing the problem of log values in R. The log(1-0.99999999999999999) is giving -Inf while log(1e-18) gives finite answer. Any suggestion to deal with this problem? Thank you [[alternative HTML version deleted]]
?log1p On January 10, 2021 12:53:14 AM PST, Shaami <nzshaam at gmail.com> wrote:>Dear Friends I am facing the problem of log values in R. The >log(1-0.99999999999999999) is giving -Inf while log(1e-18) gives finite >answer. Any suggestion to deal with this problem? Thank you > > [[alternative HTML version deleted]] > >______________________________________________ >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >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.-- Sent from my phone. Please excuse my brevity.
On Mon, 11 Jan 2021 at 08:22, Shaami <nzshaam at gmail.com> wrote:> > Dear Friends I am facing the problem of log values in R. The > log(1-0.99999999999999999) is giving -Inf while log(1e-18) gives finite > answer. Any suggestion to deal with this problem? Thank youThis vignette has a lot of good information about log of small numbers. vignette(package = "Rmpfr", "log1mexp-note") https://cran.r-project.org/web/packages/Rmpfr/vignettes/log1mexp-note.pdf Regards Martin M. S. Pedersen [[alternative HTML version deleted]]