Can you please give us more context? R can't represent numbers on the
entire real line, and it's difficult to imagine this sample making any
sense in any applied context.
I would normally think to try:
mm <- .Machine$double.xmax
runif(4, min = -mm, max = mm)
but that doesn't work (it gives all Inf) because internally (see the
code at
https://github.com/r-devel/r-svn/blob/3bde0ee96c3f97050be6b297c28c9edcf9c93eeb/src/nmath/runif.c#L37
)
R picks a uniform deviation on (0,1) and then scales it by (a+(b-a)*u);
while R can handle mm above as a floating point number, it can't handle
(mm-(-mm)) = 2*mm
runif(4, min = -mm/2, max = mm/2)
but even this will work very badly because of floating-point imprecision
(see below).
Maybe we can help if you can tell us more about your ultimate goal.
cheers
Ben Bolker
set.seed(101); runif(100, min = -mm/2, max = mm/2)
[1] -2.297481e+307 -8.200630e+307 3.769475e+307 2.834789e+307
-4.496826e+307
[6] -3.594401e+307 1.525642e+307 -2.993750e+307 2.193401e+307
8.238568e+306
[11] 6.827562e+307 3.718973e+307 4.170155e+307 7.759462e+307
-8.067940e+306
[16] 1.623672e+307 5.760458e+307 -4.959503e+307 -1.587959e+307
-8.294366e+307
[21] 3.608178e+307 8.212536e+307 -5.153051e+307 2.895392e+307
7.609974e+307
[26] 5.316134e+307 -7.708282e+307 -1.988109e+307 -1.681720e+307
2.864715e+307
[31] -1.377983e+307 -3.218150e+307 -5.433874e+307 -6.055168e+307
4.190616e+306
[36] 7.433077e+307 -5.271327e+307 5.649844e+307 -8.625921e+307
7.636680e+307
[41] -1.169188e+307 -1.041679e+307 4.686396e+307 -3.002843e+307
-1.899134e+307
[46] -4.794550e+307 -7.701180e+307 7.431367e+307 4.884217e+307
-7.055287e+307
[51] -7.564472e+307 -1.188465e+307 3.231789e+307 4.213006e+307
-8.537088e+306
[56] 5.101596e+307 3.232891e+307 3.362343e+306 3.430102e+307
1.586925e+307
[61] 5.655357e+307 5.573657e+307 1.976310e+307 8.869991e+307
6.170412e+307
[66] 3.874090e+307 -8.645444e+307 -3.504059e+307 6.884230e+307
7.934061e+307
[71] -4.774349e+307 7.849912e+307 1.199097e+307 6.162320e+307
5.776009e+307
[76] -3.955413e+307 -8.138136e+307 -4.944723e+307 3.111675e+307
8.250169e+307
[81] 3.330406e+307 4.958091e+307 4.958730e+307 8.679169e+307
-8.805305e+307
[86] 8.136105e+307 -3.183070e+307 -1.294243e+307 -6.570628e+307
-8.658979e+307
[91] 2.813381e+307 7.455633e+307 3.870431e+307 -5.699560e+307
-4.672777e+307
[96] 6.048322e+307 -2.051645e+307 -4.807502e+307 -7.749484e+307
-7.869860e+307
)
On 7/28/25 12:00, Daniel Lobo 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?
______________________________________________
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--
Dr. Benjamin Bolker
Professor, Mathematics & Statistics and Biology, McMaster University
Director, School of Computational Science and Engineering
* E-mail is sent at my convenience; I don't expect replies outside of
working hours.
______________________________________________
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.
