[R] using "sample()" for a vector of length 1

[Hadley Wickham]

Did you look at the examples in sample?

# sample()'s surprise -- example
x <- 1:10
    sample(x[x >  8]) # length 2
    sample(x[x >  9]) # oops -- length 10!
    sample(x[x > 10]) # length 0

## For R >= 2.11.0 only
resample <- function(x, ...) x[sample.int(length(x), ...)]
resample(x[x >  8]) # length 2
resample(x[x >  9]) # length 1
resample(x[x > 10]) # length 0

Hadley

On Thu, Jul 22, 2010 at 3:31 PM, Jon BR <jonsleepy at gmail.com> wrote:
> Hi All,
>    I'm trying to use the "sample" function within a loop where the
> vector being sampled from (the first argument in the function) will
> vary in length and composition.  When the vector is down in size to
> containing only one element, I run into the "undesired behaviour"
> acknowledged in the ?sample help file.  I don't want sample(10,1) to
> return a number from within 1:10, but rather I'd just want it to
> return 10 every time.
>
> Example):
>
>
> Actual:
>> sample(10,1)
> [1] 2
>> sample(10,1)
> [1] 9
>> sample(10,1)
> [1] 4
>
>
> Desired:
>> sample(10,1)
> [1] 10
>> sample(10,1)
> [1] 10
>> sample(10,1)
> [1] 10
>
>
> Perhaps sample is not the appropriate function.  I dunno.  Any thoughts?
>
> Regards,
> Jonathan
>
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-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/