Displaying 20 results from an estimated 7000 matches similar to: "RNG R/Splus compatibility"
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
2008 Aug 14
2
[R] RNG Cycle and Duplication (PR#12540)
This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.
---559023410-851401618-1218751024=:15885
Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE
I didn't describe the problem clearly. It's about the number of distinct=20
values. So just
1999 May 04
1
rnorm
Brian
I've been playing a bit with the Wichmann-Hill RNG. I would prefer to have
normally distributed random numbers and I think I have things generally worked
out to use Wichmann-Hill and then Box-Muller. In the process, I was looking at
R's rnorm.c, but could not figure out what transformation is used in R to
convert uniform rv's to normal rv's. Do you know? It looks like there
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 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
>
2019 Feb 26
0
bias issue in sample() (PR 17494)
Kirill,
I think some level of collision is actually expected! R uses a 32bit MT
that can produce 2^32 different doubles. The probability for a collision
within a million draws is
> pbirthday(1e6, classes = 2^32)
[1] 1
Greetings
Ralf
On 26.02.19 07:06, Kirill M?ller wrote:
> Gabe
>
>
> As mentioned on Twitter, I think the following behavior should be fixed
> as part of the
2018 Mar 05
1
Random Seed Location
On Sun, Mar 4, 2018 at 3:23 PM, Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
> On 04/03/2018 5:54 PM, Henrik Bengtsson wrote:
>>
>> The following helps identify when .GlobalEnv$.Random.seed has changed:
>>
>> rng_tracker <- local({
>> last <- .GlobalEnv$.Random.seed
>> function(...) {
>> curr <- .GlobalEnv$.Random.seed
2019 Feb 26
1
bias issue in sample() (PR 17494)
Ralf
I don't doubt this is expected with the current implementation, I doubt
the implementation is desirable. Suggesting to turn this to
pbirthday(1e6, classes = 2^53)
## [1] 5.550956e-05
(which is still non-zero, but much less likely to cause confusion.)
Best regards
Kirill
On 26.02.19 10:18, Ralf Stubner wrote:
> Kirill,
>
> I think some level of collision is actually
2019 Feb 26
2
bias issue in sample() (PR 17494)
Gabe
As mentioned on Twitter, I think the following behavior should be fixed
as part of the upcoming changes:
R.version.string
## [1] "R Under development (unstable) (2019-02-25 r76160)"
.Machine$double.digits
## [1] 53
set.seed(123)
RNGkind()
## [1] "Mersenne-Twister" "Inversion"??????? "Rejection"
length(table(runif(1e6)))
## [1] 999863
I don't
2001 Jan 23
0
1.2.1 segfault
I've trapped this segfault with gdb, but I'm not sure what it means or what to do
next.
Paul
_____
$ R -d gdb
GNU gdb 4.17
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is
2007 Sep 23
0
initial scrambling of seed in do_setseed / RNG_Init
I would like to suggest a modification of initial scrambling of the
seed in RNG_Init (called from do_setseed). The modified code is
equivalent, but faster. Patch against R-devel_2007-09-22 follows
--- R-devel-orig/src/main/RNG.c 2007-09-02 07:49:35.000000000 +0200
+++ R-devel-modif/src/main/RNG.c 2007-09-23 10:51:59.234566440 +0200
@@ -216,8 +216,8 @@
BM_norm_keep = 0.0; /* zap Box-Muller
2000 Feb 22
2
reproducing Box-Muller numbers
There seems to be a minor problem with reproducing numbers from rnorm with
Box-Muller. The pattern suggests it might have something to do with the value
that gets dropped when an odd number of numbers is requested. (Details below.)
Also, could "user-supplied" be added as an option for normal.kind in RNGkind.
I'm sure the Box-Muller in R is better than my own attempt, but I would
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()
2008 Aug 14
2
RNG Cycle and Duplication
Hello all,
I am generating large samples of random numbers. The RNG help page says:
"All the supplied uniform generators return 32-bit integer values that are
converted to doubles, so they take at most 2^32 distinct values and long
runs will return duplicated values." But I find that the cycles are not
the same as the 32-bit integer.
My test indicated that the cycles for
2008 Aug 14
0
[R] RNG Cycle and Duplication (PR#12537)
Shengqiao Li wrote:
> Hello all,
>
> I am generating large samples of random numbers. The RNG help page
> says: "All the supplied uniform generators return 32-bit integer
> values that are converted to doubles, so they take at most 2^32
> distinct values and long runs will return duplicated values." But I
> find that the cycles are not the same as the 32-bit
2008 Aug 14
0
[R] RNG Cycle and Duplication (PR#12538)
Shengqiao Li wrote:
> Hello all,
>
> I am generating large samples of random numbers. The RNG help page says:
> "All the supplied uniform generators return 32-bit integer values that are
> converted to doubles, so they take at most 2^32 distinct values and long
> runs will return duplicated values." But I find that the cycles are not
> the same as the 32-bit
2018 Mar 04
0
Random Seed Location
On 04/03/2018 5:54 PM, Henrik Bengtsson wrote:
> The following helps identify when .GlobalEnv$.Random.seed has changed:
>
> rng_tracker <- local({
> last <- .GlobalEnv$.Random.seed
> function(...) {
> curr <- .GlobalEnv$.Random.seed
> if (!identical(curr, last)) {
> warning(".Random.seed changed")
> last <<- curr
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
2003 Mar 03
0
R-devel RNG change
I find the documention for RNGversion in R-devel is a bit misleading,
and suggest adding a sentence to make it clear that the meaning of
"default" is not set to its meaning in the earlier R version:
`RNGversion' can be used to set the random generators as they were
in an earlier R{} version (for reproducibility). RNGversion does
not set the meaning of
2003 Jun 13
0
Testing the R RNGs
I have applied L'Ecuyer's TESTU01 suite of RNG tests
to the RNGs in R. TESTU01 offers three increasingly
more stringent suites, called "Small Crush", "Crush" and
"Big Crush". If a particular RNG fails Small Crush, there
is no need to apply Big Crush.
Below I summarize the results:
Number of Tests Failed
Small Crush Crush Big Crush