[R] question about R

[Patrizio Frederic]

# density function
desp <- function(x,lambda) {
  return(lambda * exp(-lambda*x)*(x>=0))
}
# cum. probability function
pesp <- function(q,lambda) {
  return((1-exp(-lambda*q)))
}
# quantile function
qesp <- function(p,lambda) {
  return(-lambda^{-1}*log(1-p))
}
# random sample
resp <- function(n,lambda) {
  return(qesp(runif(n),lambda))
}
resp(100,lambda=2) # generates 100 samples from the exponential
distribution with par 2


On Tue, May 11, 2010 at 6:36 PM,  <khazaei at ceremade.dauphine.fr> wrote:
> Hi,
> At each iteration in my program,I need to generate  tree vectors,X1,X2,X3,
> from exponential distribution with parameters a1,a2,a3. Can you help me
> please how can I do it such that it take a little time?
>
> thank you
> khazaei
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
+-------------------------------------------------
| Patrizio Frederic, PhD
| Assistant Professor,
| Department of Economics,
| University of Modena and Reggio Emilia,
| Via Berengario 51,
| 41100 Modena, Italy
|
| tel:  +39 059 205 6727
| fax:  +39 059 205 6947
| mail: patrizio.frederic at unimore.it
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