Displaying 20 results from an estimated 20000 matches similar to: "R-alpha: random number generator"
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
2018 Sep 21
3
Bias in R's random integers?
Not sure what should happen theoretically for the code in vseq.c, but
I see the same pattern with the R generators I tried (default,
Super-Duper, and L'Ecuyer) and with with bash $RANDOM using
N <- 10000
X1 <- replicate(N, as.integer(system("bash -c 'echo $RANDOM'", intern = TRUE)))
X2 <- replicate(N, as.integer(system("bash -c 'echo $RANDOM'",
2000 Jan 19
1
random number generator
This question may not be specific to R, but I'm using R so here goes:
Since R is slow (as is Splus) I want to split a simulation and run it on
2 or 3 systems at once. The simulations involve generating a large number
of random values. How can I set .Random.seed so that the succession of
random values don't overlap across systems.
I see that when I invoke R and give command runif(1) a
1999 Apr 28
1
R random number generator
R 0.64 on windows NT 4.0
Sometimes I got an error message by doing this
> .Random.seed <- c(1, 1:2)
> .Random.seed
[1] 1 1 2
> runif(5)
Warning: Wrong length .Random.seed; forgot initial RNGkind? set to Wichmann-Hill[1] 0.02253721 0.84832584 ........
Sometimes I do not get error message:
> .Random.seed <- c(1, 1:2)
> .Random.seed
[1] 1 1 2
> runif(1)
[1] 0.5641106
>
1997 Nov 24
0
R-alpha: random number generator -- S-plus's
--Multipart_Mon_Nov_24_14:51:09_1997-1
Content-Type: text/plain; charset=US-ASCII
>>>>> "PaulG" == Paul Gilbert <pgilbert@bank-banque-canada.ca> writes:
MM> The code is basically in V&R 1 and 2; V&R2 on p.167. I have it as a
MM> C function that I used to dyn.load into S-plus in order
MM> to prove that S-plus was using it.
1998 Dec 01
0
Random Number Generators, .Random.seed and all that..
As some of you know,
we have been thinking of allowing the possibility of a
CHOICE of the kind of random number generator (=: RNG) to use in R.
The current R-release snapshot even has some code in it;
however, this will be changed quite a bit. Here is a kind of informal
RFC (request for comments / request for criticism / ..):
1a. With the new scheme, we still want that
save(..) &
1999 Jun 12
0
Random numbers
Hi,
I have a few questions about the RNG in R; apologies if these are dumb
questions:
1. It is my understanding that, among the three types of random number
generators available in R now, the best one is the Marsaglia Multicarry. Is
this correct?
2. How does the best RNG in R compare (in terms of quality) to the RNG in
SPlus? (based on Marsaglia's Super Duper)? Does the Super-Duper in
2003 Jan 14
1
Random number generator in R compared to S
I''m doing some simulations for which i need to use both S-plus and R.
I generate in S+ some random normal distributions to define one dataset by
iteration. I need to use the same dataset generated in S-plus in R.
I was first thinking to generate in R the same dataset by using the same
random number generator with a fixed seed. But It seems that S-plus and R
don''t use the same
2003 Jun 12
1
Tested Random Number Generator
Dear All,
The editor of a journal to which I had submitted a publication asked
whether R has a "tested random number generator." My paper included
Monte Carlo simulations generating random normal and random chi-square
values.
help(rnorm) lists
Wichura, M. J. (1988) Algorithm AS 241: The Percentage Points of
the Normal Distribution. Applied Statistics, 37, 477-484.
as a
2018 Sep 21
0
Bias in R's random integers?
On 9/21/18 6:38 PM, Tierney, Luke wrote:
> Not sure what should happen theoretically for the code in vseq.c, but
> I see the same pattern with the R generators I tried (default,
> Super-Duper, and L'Ecuyer) and with with bash $RANDOM using
>
> N <- 10000
> X1 <- replicate(N, as.integer(system("bash -c 'echo $RANDOM'", intern = TRUE)))
> X2 <-
2011 Jul 25
1
Problem with random number simulation
Hi this is my first post. I am trying to run a simulation for a computer
playing Von Neumann poker and adjusting it's expectation of an opponent's
behavior according to how the opponent plays. This program involves random
generation of "hands" and shifting of parameters. However, when I run the
code, no errors come up, but the program doesn't do anything. Could someone
2012 Oct 03
3
Fastest non-overlapping binning mean function out there?
Hi,
I'm looking for a super-duper fast mean/sum binning implementation
available in R, and before implementing z = binnedMeans(x y) in native
code myself, does any one know of an existing function/package for
this? I'm sure it already exists. So, given data (x,y) and B bins
bx[1] < bx[2] < ... < bx[B] < bx[B+1], I'd like to calculate the
binned means (or sums)
2005 Nov 17
2
R questions
Dear Sir/Madam,
I am a beginner in R. Here is my questions.
1. Can you give me one test for randomness (a name and descriptive
paragraph is sufficient).
2. I have learned a uniform random number generator [e.g. not the
algorithms: i)Wichmann-Hill, ii) Marsaglia-Multicarry, iii) Super-Duper
(Marsaglia), iv) Mersenne-Twister, v) TAOCP-1997 (Knuth), or vi) TAOCP-2002
(Knuth)] . Is there any other
2010 Jan 04
2
Existing windows server to XEN howto?
I would like to move an existing W2K3 install onto my new super duper
xen box -- Installing linux based machine is no issue, it''s the windows
ones that keep getting me. I have Acronis which we usually use for bare
metal restores, and it seems that bare metal restores don''t want to work
too well with XEN, any assistance/help/ideas ?
2018 Sep 20
4
Bias in R's random integers?
Hello,
On Thursday, September 20, 2018 11:15:04 AM EDT Duncan Murdoch wrote:
> On 20/09/2018 6:59 AM, Ralf Stubner wrote:
> > On 9/20/18 1:43 AM, Carl Boettiger wrote:
> >> For a well-tested C algorithm, based on my reading of Lemire, the
> >> unbiased "algorithm 3" in https://arxiv.org/abs/1805.10941 is part
> >> already of the C standard library in
2011 Apr 21
6
ssh_authorized_key fails when home directory doesn't exist
Here is my situation:
1. We use Active directory (LDAP) to store all user info which is retrieved from linux
2. A home directory is not created until the first time the user logs into the linux system
I am using the ssh_authorized_key type to push out my ssh keys to every system. However, because I haven''t logged into every system at least once. Puppet errors out due to a missing
2008 Aug 14
2
[R] RNG Cycle and Duplication (PR#12540)
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while the remaining parts are likely unreadable without MIME-aware tools.
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I didn't describe the problem clearly. It's about the number of distinct=20
values. So just
2006 Jun 04
3
Absolutize URLs in a string
I wonder - do we have some helper/processor/gem to automatically
convert all URLs in a passed string to their canonical equivalent -
i.e. with the protocol, host and such prepended based on the Rails
environment. Super-duper infty for RSS feeds (I hate their
requirement for canonical URLs everywhere).
--
Julian ''Julik'' Tarkhanov
please send all personal mail to
me at
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
2006 Aug 31
1
Interface for package supplied random number generator
Hi,
As you probably know, there is a problem with the interface for adding uniform
random number generators in R (see by article in R News 5/2, November 2005).
There exists a mechanism called "user-supplied" that allows users of R
to run their own generator in R. However, there is no such mechanism for
package writers. Those who want to add their own generators abuse