similar to: Tested Random Number Generator

Displaying 20 results from an estimated 2000 matches similar to: "Tested Random Number Generator"

2016 Aug 31
1
A bug in the R Mersenne Twister (RNG) code?
On 30 August 2016 at 18:29, Duncan Murdoch wrote: | I don't see evidence of a bug. There have been several versions of the | MT; we may be using a different version than you are. Ours is the | 1999/10/28 version; the web page you cite uses one from 2002. | | Perhaps the newer version fixes some problems, and then it would be | worth considering a change. But changing the default RNG
2016 Aug 30
4
A bug in the R Mersenne Twister (RNG) code?
Whomever, I recently sent the "bug report" below toR-core at r-project.org and have just been asked to instead submit it to you. Although I am basically not an R user, I have installed version 3.3.1 and am also the author of a statistics program written in Visual Basic that contains a component which correctly implements the Mersenne Twister (MT) algorithm. I believe that it is
2009 May 12
4
different results on linux and windows
Dear R experts, we are preparing an R-package to compute the Oja Median which contains some C++ code in which random numbers are needed. To generate the random numbers we use the following Mersenne-Twister implementation: // MersenneTwister.h // Mersenne Twister random number generator -- a C++ class MTRand // Based on code by Makoto Matsumoto, Takuji Nishimura, and Shawn Cokus // Richard J.
2008 Aug 17
1
Wichmann-Hill Random Number Generator and the Birthday Problem
Dear all, Recently I am generating large random samples (10M) and any duplicated numbers are not desired. We tried several RNGs in R and found Wichmann-Hill did not produce duplications. The duplication problem is the interesting birthday problem. If there are M possible numbers, randomly draw N numbers from them, the average number of dupilcations D = N(N-1)/2/M. For Knuth-TAOCP and
2019 Feb 26
2
bias issue in sample() (PR 17494)
Gabe As mentioned on Twitter, I think the following behavior should be fixed as part of the upcoming changes: R.version.string ## [1] "R Under development (unstable) (2019-02-25 r76160)" .Machine$double.digits ## [1] 53 set.seed(123) RNGkind() ## [1] "Mersenne-Twister" "Inversion"??????? "Rejection" length(table(runif(1e6))) ## [1] 999863 I don't
2019 Feb 26
1
bias issue in sample() (PR 17494)
Ralf I don't doubt this is expected with the current implementation, I doubt the implementation is desirable. Suggesting to turn this to pbirthday(1e6, classes = 2^53) ## [1] 5.550956e-05 (which is still non-zero, but much less likely to cause confusion.) Best regards Kirill On 26.02.19 10:18, Ralf Stubner wrote: > Kirill, > > I think some level of collision is actually
2000 May 25
4
Needed: Understading runif() output :-)
Dear all, I have been trying to understand what runif() is telling me. I am generating lots of numbers (billions and billions (wow, I''ve dreamed about saying that for many years... :-) ), for a distribution that has the following quantile function: 1 / (2 * sqrt(1 - p)) (that is, the distribution has a lower cutoff) As you can imagine, this has rather heavy upper tail. I was
2003 Oct 20
1
Random Number Generator RNGkind() under "R CMD check" (PR#4691)
Full_Name: Wolfgang Huber Version: 1.8.0 OS: Linux Submission from: (NULL) (193.174.58.146) The man page for RNGkind says that the default is Mersenne-Twister, and when I start R interactively, I get in fact > RNGkind() [1] "Mersenne-Twister" "Inversion" However, during the execution of "R CMD check" I get > > ### ** Examples > > > > RNGkind()
2013 Feb 21
1
limitations to random number generator in 64-bits machines
Dear List, Recently I got the comment that the implementation of the random number generator used by default in R (Mersenne-Twister) could not be "safe" for 64-bits machines, so I decided to put the question here because I do not have expertise in that topic, and because this question could be "too technical for R-help's audience". I apologise if this is not the case.
2005 Dec 15
1
precision of rnorm
How many distinct values can rnorm return? I assume that rnorm manipulates runif in some way, runif uses the Mersenne Twister, which has a period of 2^19937 - 1. Given that runif returns a 64 bit precision floating point number in [0,1], the actual period of the Mersenne Twister in a finite precision world must be significantly less. One of the arguments for Monte Carlo over the bootstrap is
2006 Sep 25
1
Initialising Mersenne-Twister with one integer
Hi, It seems to me that the Mersenne-Twister PRNG can be initialised using one integer instead of 624 integers, since inside RNG.c code there's a function defined as MT_sgenrand(Int32). How do I actually set this seed within R? I've tried: > .Random.seed <- c(3, 1) > runif(1) Error in runif(1) : .Random.seed has wrong length In addition, is '3' actually the
2016 Sep 01
2
A bug in the R Mersenne Twister (RNG) code?
On 08/30/2016 06:29 PM, Duncan Murdoch wrote: > I don't see evidence of a bug. There have been several versions of the > MT; we may be using a different version than you are. Ours is the > 1999/10/28 version; the web page you cite uses one from 2002. > > Perhaps the newer version fixes some problems, and then it would be > worth considering a change. But changing the
2011 Aug 05
2
Question on RNG
Hi all, I have happened to work on MS .NET for sometime now, and I found that this language offers RNG what is called as Donald E. Knuth's subtractive random number generator algorithm (found here: http://msdn.microsoft.com/en-us/library/system.random.aspx#Y12). ? Here I was wondering whether R also have same RNG in it's inventory, so looked at ?set.seed. There I found 2 related RNGs
2013 Feb 18
2
Random number generator used in 'runif'
Dear list, For the implementation of a particular optimization algorithm it is very important the random number generator. I would like to know if somebody could tell me what is the random number generator used by default in the 'runif' function. >From the help page of 'runif' and '.Random.seed' I guess that the default algorithm is 'Mersenne-Twister', but I
2008 Aug 12
3
aligned memory allocation in C
Hi, I'm currently R porting SF Mersenne Twister algorithm of Matsumoto and Saito. To get the full power of their code, I want to use their fonction fill_array32 which need aligned memory. That is to say I need to use the C function memalign on windows, posix_memalign on linux and classic malloc on Mac OS. In 'writing R extenstion', they recommand to use R_alloc function to
2008 Aug 12
3
aligned memory allocation in C
Hi, I'm currently R porting SF Mersenne Twister algorithm of Matsumoto and Saito. To get the full power of their code, I want to use their fonction fill_array32 which need aligned memory. That is to say I need to use the C function memalign on windows, posix_memalign on linux and classic malloc on Mac OS. In 'writing R extenstion', they recommand to use R_alloc function to
2006 Aug 28
1
Speed of runif() on different Operating Systems
Dear list, I have noticed surprisingly big performance differences of runif() between Windows XP and (Debian) linux on similar CPUs (Pentium D 3.0GHz (WinXP)/3.2GHz (Linux)) and I wonder if there is a simple explanation for the difference. On a linux system (with a slightly better CPU and 1GB more RAM), execution of runif() seems to consume about 80% more CPU time than on a Windows XP
1998 Nov 04
3
simple questions about R
A few simple questions from a novice R user. (I am running R version 0.62.3 Beta (Sept 8, 1998) under Windows NT.) 1) How do I time the execution of a function/program in R for Windows? Is there the equivalent of a dos.time function? 2) Can anyone send me details on the random number generator used by R (period, etc.). Also, why is it different from the SuperDuper RNG in S? 3) Will there
2011 Feb 02
4
testing randomness of random number generators with student t-test?
Hi, subject more or less says it all. I freely admit to not having bothered to find some of the online papers about method of testing the quality of random number generators -- but in an idle moment I wondered what to expect from something like the following: randa<-runif(1000) randb<-runif(1000) t.test(randa,randb)$p.value var.test(randa,randb)$p.value [repeat ad nauseum] Is the
2009 Nov 16
2
(Parallel) Random number seed question...
Hi All, I have k identical parallel pieces of code running, each using n.rand random numbers.? I would like to use the same RNG (for now), and set the seeds so that I can guarantee that there are no overlaps in the random numbers sampled by the k pieces of code.? Another side goal is to have reproducibility of my results.? In?the past I have used C with SPRNG for this task, but I'm hoping