R help - Apr 2006 - Generic code for simulating from a distribution.

Hello all,

I have the code below to simulate samples of certain size from a
particular distribution (here,beta distribution) and compute some
statistics for the samples.

betasim2<-function(nsim,n,alpha,beta)
{
	sim<-matrix(rbeta(nsim*n,alpha,beta),ncol=n)
	xmean<-apply(sim,1,mean)
	xvar<-apply(sim,1,var)
	xmedian<-apply(sim,1,median)
simset<-data.frame(sampleno=seq1:nsim),means=xmean,vars=xvar,medians=xmedian)
	return(simset)
}

I can write a similar coding for any distribution individually.
Now, I would like to have a generic code, say if I specify the
distribution with the parameters and simulation and sample size I would
like to have the simulations done for the mentioned distribution and the
statistics performed.

I would appreciate any help in doing so?

Thanks for your time.
Mathangi


Mathangi Gopalakrishnan
Graduate student
Dept of Mathematics and Statistics
University of Maryland, Baltimore County
Baltimore, MD

Hi,

have a look at the packages distr and distrSim which are on CRAN.

hth
Matthias

----- original Nachricht --------

Betreff: [R] Generic code for simulating from a distribution.
Gesendet: Mo, 10. Apr 2006
Von: matgopa1 at umbc.edu
> Hello all,
> 
> I have the code below to simulate samples of certain size from a
> particular distribution (here,beta distribution) and compute some
> statistics for the samples.
> 
> betasim2<-function(nsim,n,alpha,beta)
> {
> 	sim<-matrix(rbeta(nsim*n,alpha,beta),ncol=n)
> 	xmean<-apply(sim,1,mean)
> 	xvar<-apply(sim,1,var)
> 	xmedian<-apply(sim,1,median)
>
simset<-data.frame(sampleno=seq1:nsim),means=xmean,vars=xvar,medians=xmedian
> )
> 	return(simset)
> }
> 
> I can write a similar coding for any distribution individually.
> Now, I would like to have a generic code, say if I specify the
> distribution with the parameters and simulation and sample size I would
> like to have the simulations done for the mentioned distribution and the
> statistics performed.
> 
> I would appreciate any help in doing so?
> 
> Thanks for your time.
> Mathangi
> 
> 
> Mathangi Gopalakrishnan
> Graduate student
> Dept of Mathematics and Statistics
> University of Maryland, Baltimore County
> Baltimore, MD
> 
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> 
--- original Nachricht Ende ----