Displaying 20 results from an estimated 4000 matches similar to: "birthday problem (factorial limit)"
2007 Nov 06
1
Algorithms for coincidences
I'm looking at algorithms for determining coincidences. In educational
testing, it is interesting to look at cheating via the birthday problem
where I can assess the probability of n students having the same test
score in a class of size k.
I was writing my own code for the b-day problem until I ran into the
qbirthday() function, which has solutions for the overflow problems I
kept running
2006 Jan 23
1
proposed pbirthday fix
Recent news articles concerning an article from The Lancet with fabricated
data indicate
that in the sample containing some 900 or so patients, more than 200 had
the same
birthday. I was curious and tried out the p and q birthday functions but
pbirthday
could not handle 250 coincidences with n = 1000. The calculation of upper
prior
to using uniroot produces NaN,
upper<-min(n^k/(c^(k-1)),1)
2000 Apr 25
2
Recursive Computation in R
Hi there,
I have written a function to calculate factorials as follows:
fact <- function(x) {
recurse <- x > 1
x[!recurse] <- 1
if( any(recurse) ) {
y <- x[recurse]
x[recurse] <- y * fact( y - 1 )
}
x
}
I want to be able to do the famous birthday problem, which will involve
the computation of 365!, however it shall get cancelled
2008 Apr 28
5
Fractional Factorial Design
Hi all,
Does anybody know if it is possible to build a fractional factorial design
in R? That is, suppose that we want do design an experiment with 3 factors
with 2, 3 and 3 levels, respectivly. However we want to consider, let's say,
only 6 from all possible level combinations. Does R design such experiment?
Thanks in advance,
Caio
[[alternative HTML version deleted]]
1999 Jun 23
4
does a factorial function exist
I've looked through the documentation with R-0.64.1 and have been unable
to find a high-level function for evaluation of factorials (i.e., n!, not
factorial designs). Is there such a function?
It is trivial to code, so everyone could write their own, but it also
would be worthwhile as a standard tool. I'm guessing I am just
overlooking it.
2019 Apr 15
2
Happy 15th Birthday, CentOS!
CentOS is 15 years old today!
Hear the story from some of our community members at
https://blog.centos.org/2019/04/centos15-2/
Do you have your own story? Drop me a note - rbowen at centosproject.org -
to tell me about it.
--
Rich Bowen - rbowen at redhat.com
@CentOSProject // @rbowen
859 351 9166
2000 Oct 26
3
Happy Birthday portable OpenSSH!
It was one year ago today that I released a patch to get OpenSSH
compiling on Linux. I had no idea just how much trouble releasing that
patch would get me into :)
Within days I was inundated with patches, improvements and portability
enhancements - contributions which have made portable OpenSSH the
success it is today.
So allow me to thank the current developers and all of you who have
2002 May 08
3
mv to /tmp = baby's birthday jpg's lost.
Hello all,
Yesterday I moved using the mv command in Redhat 7.2 ext3 file system to
move to /tmp my /mnt/win98/"My Pictures" directory to tmp. The command
executed normally, and I actually verified that the subdir was created
in /tmp and the files were there in /tmp/"My Pictures"
I was doing this to temporarily free space on my vfat windows 98
partition. When I went
2007 Dec 06
1
"Happy Birthday Asterisk"
Sorry if this dupes, didn't seem to post to the list when I emailed it a
few hours ago.
Regards,
Dean Collins
Cognation Pty Ltd
dean at cognation.net
+1-212-203-4357
+61-2-9016-5642 (Sydney in-dial).
________________________________
From: Dean Collins
Sent: Thursday, December 06, 2007 2:49 PM
To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
Subject: "Happy
2009 Apr 22
5
large factorials
I am working on a project that requires me to do very large factorial
evaluations. On R the built in factorial function and the one I created
both are not able to do factorials over 170. The first gives an error and
mine return Inf.
Is there a way to have R do these larger calculations (the calculator in
accessories can do 10000 factorial and Maple can do even larger)
--
View this message in
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
2002 Jan 16
1
factorials
I'm a total newbie at using R, and so there probably
is a better way to do this. However, I couldn't find
one, and so maybe this will help someone.
I was calculating log-likelihoods using a multinomial
model, and found that for large n, prod(n:1) wouldn't
work to calculate factorials (e.g., prod(200:1) =
Inf). The below function calculates the natural log
of a factorial (e.g.
2000 Jul 06
1
factorial(), modulus()
Dear R friends,
I was wondering if there were factorial and modulus functions out there
that I've somehow overlooked?
-P.
--
Peter L. Hurd, Ph.D.
phurd at uts.cc.utexas.edu
http://www.zo.utexas.edu/research/phurd fax 512.471-3878
Section of Integrative Biology, University of Texas, Austin TX 78712 USA
2004 Jun 25
1
ties in runif() output
I get ties in output from runif() when I generate as few as 10^5
variates and get quite a lot when I generate 10^6. Is this
expected?? I haven't seen any duplication with rnorm(10^6), but
see varying amounts of duplication using rexp(), rbeta() and
rgamma(). I would have thought that there'd be enough precision
that one wouldn't get ties until generating samples larger than this..
2005 Apr 04
1
Handling very large integers with factorial and combinat (nCm)
Dear list,
perhpas this question is more suitable for R-dev but since I am not
really a developer I post it here first.
Apparently the following lines do not create any problem in R:
library(combinat)
r <- 20; b <- 2;
sum( sapply(0:r,function(x) nCm(r,x)^(2*b)) ) > 2^64
while in C I obtain an overflow of data even using unsigned long long
and with long double I incurr in precision
2003 Feb 14
2
factorial function
Sorry for the stupid question, but is there the factorial function in
R? I tried to find it using help.search('factorial') but got nothing
appropriate.
Many thanks,
-Serge
2001 Dec 04
3
factorial() not here (PR#1194)
Version 1.3.1 (2001-08-31)
factorial() is not in R. It is in S-Plus with the definition
factorial <- function(n) gamma(n + 1)
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2006 Jan 20
3
fractional factorial design in R
Hi,
i need to create a fractional factorial design sufficient to estimate the
main effects.
The factors may have any number of levels, let's say any number from 2 to 6.
I've tried to use the library conf.design , but i cannot figure out how to
write the code.
For example, what is the code for a design with 5 factors (2x3x3x5x2) and
only main effects not confounded?
thanks in advance!
2011 Nov 29
2
Non parametric, repeated-measures, factorial ANOVA
Hi
I have data from an experiment that used a repeated-measures factorial 2x2
design (i.e. each participant contributed data to both levels of both
factors). I need a non-parametric version of the repeated-measures factorial
ANOVA to analyse the data. SPSS only has non-parametric tests for one-way
ANOVAs but I have been told that the test I need can be implemented using
the R software.
2006 Aug 18
2
4^2 factorial help
To whom it may concern:
I am trying a factorial design a system of mine that has two factors.
Each factor was set at four different levels, with one replication for
each of the combinations. My data is as follows:
A B Response
1 600 2.5 0.0257
2 600 2.5 0.0254
3 600 5