Displaying 20 results from an estimated 10000 matches similar to: "Sum of binominal distributed random numbers"
2007 Oct 24
2
analytical solution to Sum of binominal distributed random numbers?
Frede Aakmann T?gersen wrote:
> Perhaps
>
> http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA266969&Location=U2&doc=GetTRDoc.pdf
>
> is something that you can use?
Thanks a lot - that might help.
Rainer
>
>
>
> Best regards
>
> Frede Aakmann T?gersen
> Scientist
>
>
> UNIVERSITY OF AARHUS
> Faculty of Agricultural Sciences
> Dept.
2016 Mar 10
3
rmultinom.c error probability not sum to 1
Hi all,
I should have given a better explanation of my problem. Here it is.
I extracted from my code the bit that gives the error. Place this in a file called test.c
#include <math.h>
#include <R.h>
#include <Rmath.h>
#include <float.h>
#include <R_ext/Print.h>
int main(){
double prob[3] = {0.0, 0.0, 0.0};
double prob_tot = 0.;
prob[0] = 0.3*dnorm(2, 0,
2010 Jun 23
1
Generation of binomial numbers using a loop
Dea'R' helpers
I have following data -
prob = c(0.1, 0.2, 0.3, 0.4, 0.5)
frequency = c(100, 75, 45, 30, 25)
no_trials = c(10, 8, 6, 4, 2)
freq1 = rbinom(frequency[1], no_trials[1], prob[1])
freq2 = rbinom(frequency[2], no_trials[2], prob[2])
freq3 = rbinom(frequency[3], no_trials[3], prob[3])
freq4 = rbinom(frequency[4], no_trials[4], prob[4])
freq5 = rbinom(frequency[5],
2016 Mar 10
2
rmultinom.c error probability not sum to 1
Dear all,
I have a questions regarding using the c function rmultinom.c.
I got the following error message "rbinom: probability sum should be 1, but is 0.999264"
Which is thrown by:
if(fabs((double)(p_tot - 1.)) > 1e-7)
MATHLIB_ERROR(_("rbinom: probability sum should be 1, but is %g"),
(double) p_tot);
I understand my probabilities do not sum to one close enough. I
2006 Jun 02
2
Problem with mle
R 2.3.0
Linux, SuSE 10.0
Hi
I have two problems with mle - probably I am using it the wrong way so
please let me know.
I want to fit different distributions to an observed count of seeds and
in the next step use AIC or BIC to identify the best distribution.
But when I run the script below (which is part of my original script), I
get one error message for the first call of mle:
Error in
2008 Aug 21
3
[help] simulation of a simple Marcov Stochastic process for population genetics
Hi, this is my first time using R. I want to simulate the following process:
"in a population of size N, there are i individuals bearing genotype A, the
number of those bearing A is j in the next generation, which following a
binominal distribution (choose j from 2*N, the p is i/2*N), to plot the
probability of the next generations, my script is as follows. It cannot run
successfully,
2005 Mar 23
4
sampling from a mixture distribution
Dear R users,
I would like to sample from a mixture distribution p1*f(x1)+p2*f(x2). I
usually sample variates from both distributions and weight them with their
respective probabilities, but someone told me that was wrong. What is the
correct way?
Vumani
2004 Nov 08
1
coxph models with frailty
Dear R users:
I'm generating the following survival data:
set.seed(123)
n=200 #sample size
x=rbinom(n,size=1,prob=.5) #binomial treatment
v=rgamma(n,shape=1,scale=1) #gamma frailty
w=rweibull(n,shape=1,scale=1) #Weibull deviates
b=-log(2) #treatment's slope
t=exp( -x*b -log(v) + log(w) ) #failure times
c=rep(1,n) #uncensored indicator
id=seq(1:n) #individual frailty indicator
2008 Dec 16
1
simulate binary markov chain
Hi all, I was hoping somebody may know of a function for simulating a
large binary sequence (length >10 million) using a (1st order) markov
model with known (2x2) transition matrix. It needs to be reasonably
fast. I have tried the following;
mc<-function(sq,P){
s<-c()
x<-row.names(P)
n<-length(sq)
p1<-sum(sq)/n
s[1] <- rbinom(1,1,p1);
for ( i in 2:n){
s[i]
2010 Mar 13
1
What can I use instead of ks.test for the binomial distribution ?
Hello all,
A friend just showed me how ks.test fails to work with pbinom for small
"size".
Example:
x<-rbinom(10000,10,0.5)
x2<-rbinom(10000,10,0.5)
ks.test(x,pbinom,10,0.5)
ks.test(x,pbinom,size = 10, prob= 0.5)
ks.test(x,x2)
The tests gives significant p values, while the x did come from
binom with size = 10 prob = 0.5.
What test should I use instead ?
Thanks,
Tal
2023 Apr 08
1
Error message for infinite probability parameters in rbinom() and rmultinom()
On 08/04/2023 5:53 p.m., Martin Maechler wrote:
>>>>>> Christophe Dutang
>>>>>> on Sat, 8 Apr 2023 14:21:53 +0200 writes:
>
> > Dear all,
>
> > Using rmultinom() in a stochastic model, I found this function returns an error message 'NA in probability' for an infinite probability.
>
> > Maybe, a more
2003 Jan 27
1
rmultinom() -- how \\ via own C code?
I've had a need for multinomial "random number generation"
occasionally. And other people too.
The following code is currently in the
(very small ``not very high importance'') CRAN package normix
--- which I will rename to "nor1mix" very seen because of a
``name registration'' problem
I want to add "this" (well the functionality) to a
2012 Jan 30
1
mgcv bam() with grouped binomial data
Hello,
I'm trying to use the bam() function in the R mgcv package for a large set of grouped binary data. However, I have found that this function does not take data in the format of cbind(numerator, denominator) on the left hand side of the formula. As an example, consider the following
dat1 <- data.frame(id=rep(1:6, each=3), num=rbinom(18, size=10, prob=0.8), den=rbinom(18, size=5,
2013 May 23
1
sample(c(0, 1)...) vs. rbinom
Greetings.? My wife is teaching an introductory stat class at UC Davis.? The
class emphasizes the use of simulations, rather than mathematics, to get
insight into statistics, and R is the mandated tool.?? A student in the class
recently inquired about different approaches to sampling from a binomial
distribution.? I've appended some code that exhibits the idea, the gist of
which is that using
2023 Apr 08
1
Error message for infinite probability parameters in rbinom() and rmultinom()
>>>>> Christophe Dutang
>>>>> on Sat, 8 Apr 2023 14:21:53 +0200 writes:
> Dear all,
> Using rmultinom() in a stochastic model, I found this function returns an error message 'NA in probability' for an infinite probability.
> Maybe, a more precise message will be helpful when debugging.
>> rmultinom(1, 3:5, c(1/2, 1/3,
2007 Oct 17
3
how to repeat the results of a generated probabilities
hello,
I want to simulate 200 times the mean of a joint probability (y1) and 200
times the mean of another joint distribution (y2),
that is I'm expecting to get 200 means of y1 and 200 means of y2.
y1 and y2 are probabilities that I calculate from the marginal prob. (z1 and
z2 respectively) multiple by the conditional prob. (x1 and x2 respectively),
which I generaterd from the binomial
2009 Apr 17
2
Generate bivariate binomial data
Dear all,
Could someone point me to a function or algorithm to generate random
bivariate binomial data?
Some details about what I'm trying to do. I have a dataset of trees who
were categorised as not damaged or damaged. Each tree is measured twice
(once in two consecutive years). The trees can recover from the damage
but the data is clearly correlated. As a (un)damaged tree is more likely
2017 Oct 10
2
Power test binominal GLM model
Dear All
I have run the following GLM binominal model on a dataset composed by the
following variables:
TRAN_DURING_CAMP_FLG enviados bono_recibido
0 1 benchmark
0 1 benchmark
0 1 benchmark
0 1 benchmark
0 1 benchmark
0 1
2008 May 21
2
how to do pairwise sums in a matrix
I am looking for an efficient way to solve the following problem. I have a large matrix of continuous values with a small proportion of missing values. Columns correspond to variables where each variable has two measurements, call them A and B. The matrix is such that the columns are in sequence with respect to the variables. I would like to sum up the two measurements for each variable and each
2010 Sep 25
2
OT: What distribution is this?
Hi
This is OT, but I need it for my simulation in R.
I have a special case for sampling with replacement: instead of sampling
once and replacing it immediately, I sample n times, and then replace all n
items.
So:
N entities
x samples with replacement
each sample consists of n sub-samples WITHOUT replacement, which are all
replaced before the next sample is drawn
My question is: which