# [R] problem with function "rep"

Erik Iverson iverson at biostat.wisc.edu
Thu Jun 12 17:57:11 CEST 2008

```Berwin appears to be correct here.  After you do x <- x / 0.0001,
I inserted a call to round(x) - x, and received

round(x) - x
[1] 7.275958e-12 0.000000e+00 0.000000e+00

This is basically a case of FAQ 7.31.

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
>>> http://www.R-project.org/posting-guide.html
>>> <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
>> *****************************************************
>>

```