From: Charilaos Skiadas <cskiadas_at_gmail.com>

Date: Thu, 12 Jun 2008 13:39:20 -0400

return(list(sum(x),length(t)))

}

test(100)

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. Received on Thu 12 Jun 2008 - 17:45:04 GMT

Date: Thu, 12 Jun 2008 13:39:20 -0400

I believe this might do what you want a bit faster. I replaced the while loop with something that is likely to be faster. I saw no reason for the rounding you were doing, better to use as.integer at the end.

test <- function(t){

x <- rexp(t,0.1)

while(sum(x) <= t) {

x <- c(x, rexp(t,0.1))

}

x <- as.integer(x/0.0001) x <- x[cumsum(x)<=10000*t] y <- rnorm(length(x),0,1) t <- rep(y,x)

return(list(sum(x),length(t)))

}

test(100)

Btw, it is not very wise to call a variable "t", given that that's a built in function.

Haris Skiadas

Department of Mathematics and Computer Science
Hanover College

On Jun 12, 2008, at 11:27 AM, Julien Hunt wrote:

*> Hi I believe this should provide an example of the confusing behavior.
**>
**> Run this with t=100 for example:
**>
**> test=function(t){
**>
**> x=c()
**> while(sum(x)<=t){
**> ###I simply generate some numbers from an
**> exponential until the sum of these numbers gets
**> to 100(without loss of generality)
**> x=c(x,round(rexp(1,0.1),4))
**> }
**> x=x/0.0001
**>
**> y=rnorm(length(x),0,1)
**> t=rep(y,x)
**>
**> return(sum(x),length(t))
**>
**> }
**>
**> The intuition is that sum(x) and length(t) should
**> be the same. furthermore, rounding x seems since
**> all is done for it to be an integer.
**> Nevertheless, I will try Berwin Turlach's method.
**> Regards,
**> Julien
**>
**> At 17:01 12/06/2008, Erik Iverson wrote:
*

>> We need a reproducible example of this to tell

*>> you what is going on. Find a small example that
**>> exhibits the confusing behavior, and share it with the list.
**>>
**>> Julien Hunt wrote:
**>>> To whom it may concern,
**>>> I am currently writing a program where I need to use function rep.
**>>> The results I get are quite confusing. Given
**>>> two vectors A and B, I want to replicate a[1]
**>>> b[1] times, a[2] b[2] times and so on.
**>>> All the entries of vector B are positive integers.
**>>> My problem comes from the fact that if I sum up
**>>> all the elements of B, I get a certain
**>>> value x(for example 10000). And if i calculate
**>>> the length of the vector obtained after
**>>> replication, I dont always get x(10000) but
**>>> sometimes I get x sometimes I get 9999 instead of 10000.
**>>> Has this problem been reported before? Do you
**>>> need more information on my specific program.
**>>> Thanks for your time and help,
**>>> Best regards,
**>>> Julien Hunt
**>>> Julien Hunt,
**>>> PhD student and teaching assistant,
**>>> Institute of Statistics,
**>>> Université Catholique de Louvain,
**>>> Voie du Roman pays 20
**>>> B-1348 Louvain-La-Neuve,
**>>> Belgium
**>>> E-mail: Julien.Hunt_at_uclouvain.be
**>>> Tel: +32 10 / 47 94 01
**>>> *****************************************************
**>>>
**>>> [[alternative HTML version deleted]]
**>>>
**>>> --------------------------------------------------------------------
**>>> ----
**>>> ______________________________________________
**>>> 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.
**>>
**>> Julien Hunt,
**>> PhD student and teaching assistant,
**>> Institute of Statistics,
**>> Université Catholique de Louvain,
**>> Voie du Roman pays 20
**>> B-1348 Louvain-La-Neuve,
**>> Belgium
**>>
**>> E-mail: Julien.Hunt_at_uclouvain.be
**>> Tel: +32 10 / 47 94 01
*

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