[R] avoiding the sample in built function

[Kevin E. Thorpe]

On 11/23/2011 02:01 PM, sarah44 wrote:
> Dear all,
>
> I am currently working on a function in which I would like to avoid using
> the command sample().
>
> Therefore, I am now trying to make a for loop that does the same thing as
> the in built function sample
> does: Rearranging the items of a object randomly.
>
> So, the output I want to you get is the same as sample() would give me:
>
> e.g.:
> data<- c(5,4,6,7,8)
> sample(data)
>
>> data<- c(5,4,6,7,8)
>> sample(data)
> [1] 4 6 7 8 5
>> sample(data)
> [1] 6 8 4 7 5
>> sample(data)
> [1] 6 5 4 8 7
>
> Herefore I made a for loop which you can see here:
> This for loop is supposed to do the same as the sample() function, 3 times.
>
> data<- c(5,4,6,7,8)
> numsim<- 3
> n<- length(data)
> sample<- matrix(0,numsim,1)
>
>
> for (i in 1:numsim) {indices<- runif(pool, min = 1, max = n)
>                    sample[i,]<- data[indices]
>                        }
>
> the idea behind this for loop is dat it first creates randomly data by
> runif, and then it should
> somehow, by using indeces, store this 3 times in a matrix 'sample'.
> Somehow, I am stuck here and I think that the sample[,i] part is just very
> wrong. I am however
> not for a very long time an R user, so I cannot find the solution to this
> problem.
>
> Can someone give me a hint?
>
> Thanks very much!
>
> Bye, sarah
>

The only reason I can think of you wanting to avoid sample() is because 
this is homework and the list is not for homework.  If I have misjudged 
the intent of your post, please forgive me.

-- 
Kevin E. Thorpe
Biostatistician/Trialist,  Applied Health Research Centre (AHRC)
Li Ka Shing Knowledge Institute of St. Michael's
Assistant Professor, Dalla Lana School of Public Health
University of Toronto
email: kevin.thorpe at utoronto.ca  Tel: 416.864.5776  Fax: 416.864.3016