Displaying 20 results from an estimated 3000 matches similar to: "ties in runif() output"
2002 Jun 17
2
Random Beta variates
I have been trying to use the rbeta() function to generate random beta
variates with a particular mean and standard deviaiton for some simulation
problems
I am working on, however I am unsure of the relationship between the
parameters shape1 and shape2 and the mean and standard deviation of the
beta
distribution. I am guessing that there is a formula for this, but I am
unsure what it is. Can
2009 Feb 13
2
Generate random numbers in Fortran
Hi!!!
It would like to know if it exists a form to use the functions to
generate variates in FORTRAN with the same easiness I use that them in
C? Or not?
If yes. They would have some example? I would like to use the functions rbeta, rlnorm and others!
Sorry my english..rsrsrs
Thanks!!!
Fábio Mathias Corrêa University Federal of the Lavras - Brazil
Veja quais são os
2012 Aug 27
3
How to generate a matrix of Beta or Binomial distribution
Hi folks,
I have a question about how to efficiently produce random numbers from Beta
and Binomial distributions.
For Beta distribution, suppose we have two shape vectors shape1 and shape2.
I hope to generate a 10000 x 2 matrix X whose i th rwo is a sample from
reta(2,shape1[i]mshape2[i]). Of course this can be done via loops:
for(i in 1:10000)
{
X[i,]=rbeta(2,shape1[i],shape2[i])
}
However,
2010 Jun 23
1
A question about R2Winbugs
Dear R users:
I was trying to fit a HMM with mixture of Gaussian into the dataset, and I
tried to implement it by R2Winbugs. But I got the following errer.
*
Error in FUN(X[[1L]], ...) :
.C(..): 'type' must be "real" for this format*
Does anybody know what's the problem? Does R2Winbugs accept some matrix as
inits? I would really appreciate your help. Thank you very much.
2009 Mar 17
3
R does not compile any more on FreeBSD 8.0-CURRENT
On a recent FreeBSD 8.0-CURRENT (i386) building R (any version) breaks
with the following messages:
----------------------------------------------------------------------
[...snip...]
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include -DHAVE_CONFIG_H -g -O2 -c wilcox.c -o wilcox.o
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include
1999 Jul 21
1
R 0.64.2 for Windows 95/NT
I installed R 0.64.2 using "rwinst.exe" on a Windows 95 machine. The zip
files and rwinst.exe were stored in a directory "rtmp" and I wanted R to
be installed in "r0642" (by setting c:\rtmp for source directory and c:\
for install directory). After the installation was completed the main
program was in r0642 whereas all the documentation in c:\rtmp\r0642.
Is this
2012 Dec 06
1
Anomalous outputs from rbeta when using two different random number seeds
Hi, in the code below, I am drawing 1000 samples from two beta
distributions, each time using the same random number seed.
Using set.seed(80) produces results I expect, in that the differences
between the distributions are very small.
Using set.seed(20) produces results I can't make sense of. Around half of
the time, it behaves as with set.seed(80), but around half of the time, it
behaves
2003 Jul 04
1
Problem with fitdistr for beta
I have the following problem:
I have a vector x of data (0<x<=1 ) with
a U-shaped histogram and try to fit a beta
distribution using fitdistr. In fact,
hist(rbeta(100,0.1,0.1)) looks a lot like
my data.
The equivalent to
the example in the manual
sometimes work:
> a <- rbeta(100,0.1,0.1)
> fitdistr(x=a, "beta", start=list(shape1=0.1,shape2=0.1))1)
> shape1
2011 Apr 06
1
Use of the dot.dot.dot option in functions.
Hi R users:
I try this code, where "fun" is a parameter of a random generating
function name, and I pretend to use "..." parameter to pass the parameters
of different random generating functions.
What am I doing wrong?
f1<-function(nsim=20,n=10,fun=rnorm,...){
vp<-replicate(nsim,t.test(fun(n,...),fun(n,...))$p.value)
return(vp)
}
This works!
f1()
2011 Apr 07
2
Two functions as parametrs of a function.
Hi R users:
I'm trying to make a function where two of the parameters are
functions, but I don't know how to put each set of parameters for
each function.
What am I missing?
I try this code:
f2<-function(n=2,nsim=100,fun1=rnorm,par1=list(),fun2=rnorm,par2=list()){
force(fun1)
force(fun2)
force(n)
p1<-unlist(par1)
p2<-unlist(par2)
force(p1)
force(p2)
2012 Mar 13
1
Coding C++ in R. What is faster : Using bosst external libraries or R.h header file?
Hi everyone,
I have built an R package and for the sake of speed I have decided to rewrite some part of the code in C++. In my original R code I use the pnorm, qnorm, rnorm, pgamma, dgamma, rgamma, rbeta and runif function. First I was thinking in going with the boost libraries, but I noticed the functions described above are available within the R.h header file (or is it Rmath.h?).
So my
2011 Jan 20
1
Calling C++ from R
Hi All,
I am new to this area and use Rcpp to call C++ from R and try to build the
package under Windows 7. I use Rtools and R 2.10.1 32bit. Everything works
fine with me, except using R functions like "rnorm" or "runif" in the C++
code. When I use "R CMD check" the package, it always return error
** libs
making DLL ...
g++
2012 Mar 01
2
'break' function in loop
Dear R helpers,
I have some difficulties in using ''break'' function with loop, and the followings are my script. What I try to do is (1) permute ''or'' first; (2) doing t-test if this ''or'' pass criteria 1 (k=1); (3) end the loop when I get 10 permutations; (4) redo everything again but this time use criteria 2 (k=2) (I have more criteria 1:n).
2011 Mar 20
3
Part of a density plot
Suupose I have
y <- rbeta(10000, 2, 5)
and I only want to see only the density plot from x = 0 to x = 1
How do I do this?
--
Thanks,
Jim.
[[alternative HTML version deleted]]
2016 Jun 30
2
Calling C implementations of rnorm and friends
Hi all,
Looking at the body for the function rnorm, I see that the body of the
function is:
.Call(C_rnorm, n, mean, sd)
I want to implement functions that generate normal (and other) random
variables. Now, I understand that I can perfectly well just call the R
wrapper for these functions and that will be almost indistinguishable for
most purposes, but for whatever reason I wanted to try and
2008 Sep 17
3
Is there a way to not use an explicit loop?
I have a problem in where i generate m independent draws from a
binomial distribution,
say
draw1 = rbinom( m , size.a, prob.a )
then I need to use each draw to generate a beta distribution. So,
like using a beta prior, binomial likelihood, and obtain beta
posterior, m many times. I have not found out a way to vectorize
draws from a beta distribution, so I have an explicit for loop
2011 Nov 12
1
Please Help
HiI want to construct a logliikelood function in RHere is the situationy=number of particles emitted in 1 hr period~pois(30)p=probability of detection of radiation particlesx=number of particles detected by a radiation detector~pois(30p)where p~beta(a,1)I have to calculate the loglikehood for a for the range a(2,50)I wish to simulate 100 random samples for each aHere is my code:-m=481n=100x =
1997 Jul 09
1
R-beta: Problem with `rpois'
There is a problem with `rpois'. It does seem to take care about the
order of the arguments. This is an example:
> rpois(n=1,lambda=2)
[1] 3
> rpois(lambda=2,n=1)
[1] 2 0
It obviously uses the first argument as the number of samples to be
drawn, which is wrong.
I used Version 0.49 Beta (April 23, 1997).
Fredrik
1997 Jul 09
1
R-beta: Problem with `rpois'
There is a problem with `rpois'. It does seem to take care about the
order of the arguments. This is an example:
> rpois(n=1,lambda=2)
[1] 3
> rpois(lambda=2,n=1)
[1] 2 0
It obviously uses the first argument as the number of samples to be
drawn, which is wrong.
I used Version 0.49 Beta (April 23, 1997).
Fredrik
2012 Nov 09
1
Counting the numbers of items in vector according to their size
I am new to R and learned to program 10 years ago in C++. I am currently
working a project that looks at the distribution of randomly generated beta
values. I take 20 random beta values find their sum, repeat 100000 times.
Here is my code that it took me 4 hours to get
s=numeric(length=100000)
for(i in 1:100000){
pop=(rbeta(n=20,shape1=2,shape2=1))
s[i]=sum(pop)
}
So now I have them all in