I thought I was reasonably explicit that the OP should abandon the search for a uniform distribution on the whole real line and should investigate transforming the problem. If the OP really needs a distribution on the whole real line, there are infinitely many to be had but none of them is uniform. If the OP really needs a uniform distribution, there is one to be had on a finite interval, and the whole real line can be bijectively mapped onto a finite interval, just not linearly. That remains the question of interest: what does the OP *really* need?
On Tue, 5 Aug 2025 at 22:02, peter dalgaard <pda...@gmail.com> wrote: > > Or rlogis(1e6, scale=.5) which is the same thing. > > But the logistic distribution is in no reasonable sense a uniform on the > entire line, any more than the Gaussian is. > > (Some notion of a "random real" is involved in Benford's law of first digits, > but that involves having a uniform distribution of log(X) and then increasing > the range.) > > -pd > > > On 30 Jul 2025, at 14:11 , Richard O'Keefe <rao...@gmail.com> wrote: > > > > Let's look at something that *would* work if it were not that IEEE > > doubles are relatively small discrete set,. > > > > Suppose we had two things. > > - a U(0,1) uniform random generator able to generate any *real* in the > > range 0 .. 1 > > - an implementation of atanh() that works for any real in the range 0 > > .. 1 and can return any real number. > > Then atanh(runif(n)*2 - 1) would do pretty much what you want,. > > Try it in R. > > f <- function (n = 1000000) atanh(runif(n)*2 - 1) > > summary(f()) > > It turns out that working with *representable* numbers means that the > > results of f() are limited to > > roughly -18,.4 to 18.4, and with n = 1000000 the extremes are almost > > always around 7. > > Something that, for actual real numbers, could return *any* real, for > > representable numbers > > can only return -18-and-a-bit to +18-and-a-bit. > > > > This suggests a completely different approach to your original > > problem, whatever it is. > > Instead of working with the entire real line, transform your problem > > to work with the interval (0,1). > > > > On Tue, 29 Jul 2025 at 04:01, Daniel Lobo <danielobo9...@gmail.com> wrote: > >> > >> Hi, > >> > >> I want to draw a set of random number from Uniform distribution where > >> Support is the entire Real line. > >> > >> runif(4, min = -Inf, max = Inf) > >> > >> However it produces all NAN > >> > >> Could you please help with the right approach? > >> > >> ______________________________________________ > >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >> https://stat.ethz.ch/mailman/listinfo/r-help > >> PLEASE do read the posting guide > >> https://www.R-project.org/posting-guide.html > >> and provide commented, minimal, self-contained, reproducible code. > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > > https://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > -- > Peter Dalgaard, Professor, > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Office: A 4.23 > Email: pd....@cbs.dk Priv: pda...@gmail.com > ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
