[R] Help Help with sampling

[Peter Dalgaard]

Alex99 wrote:
> Hi everyone,
>
> I have a dataset(named "Mydata") which includes 4 different variables named;
> s1,s2,s3,s4 .Each variable(symptom) has 14 patients.
> I need to use random sampling to make, 5 different samples from my data with
> 5 patients in each sample. i.e. using all 4 variables I need to make 5
> different samples by changing patients(with 5 patients in each sample).
>
>
>    X8 X9 X10 X102 X110 X177 X283 X284 X286 X292 X297 X306 X308 X314
> s1  0  1   0    0    0    1    0    0    0    0    0    0    0    0
> s2  0  0   0    0    1    0    0    0    0    0    0    0    1    0
> s3  0  1   0    0    0    0    0    0    0    0    0    0    1    0
> s4  1  0   0    0    1    0    0    0    0    1    0    0    0    0
>
>
> I used this code:
>
> temp=list(NULL)
> for(i in 1:5) {temp[i]<-sample(Mydata,5, replace=F)} show(temp)
>
> but I get the following error:
> "number of items to replace is not a multiple of replacement length"
>
> any idea why I get this eeror message and how can I fix it?
> Thanks a lot.
>
>   
The direct cause is that you are not using temp[[i]]<-, but I don't
think that sample() construct does what I think you think it does
either. You might want to use replicate() instead, as in
 
 replicate(2,airquality[sample(1:153,5, replace=F),], simplify=F)

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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