Dear Alex,
Is this what you want?

my=read.table(textConnection("
X8 X9 X10 X102 X110 X177 X283 X284 X286 X292 X297 X306 X308 X314
0  1   0    0    0    1    0    0    0    0    0    0    0    0
0  0   0    0    1    0    0    0    0    0    0    0    1    0
0  1   0    0    0    0    0    0    0    0    0    0    1    0
1  0   0    0    1    0    0    0    0    1    0    0    0
 0"),header=TRUE)
closeAllConnections()
rownames(my)=paste('s',1:4,sep="")

# Five samples
res=replicate(5,my[,sample(colnames(my),5)],simplify=FALSE)

# mean for each sample
Means=do.call(rbind,lapply(res,function(x) rowMeans(x)))
rownames(Means)=paste('sample',1:5,sep="")
Means

# Global mean for sample
colMeans(Means)


HTH,

Jorge


On Thu, Oct 16, 2008 at 9:10 AM, Alex99 <loyola9988@yahoo.com> wrote:

>
>
> Hi everyone,
> I have dataset which I take random samples of it 5 times. each time I get
> the mean for rows for each sample.
> at the end I need to calculate the Average of all means for  each sample
> and
> each row. to clear it up I give an example:
> say this is my dataset.
>    X8 X9X10X12 X13 X14 X15 X16X17X18X19 X20 X21 X22
> 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 get a random sample and mean of row for that sample(5 times , but I just
> put 2 of them here to give you   an idea)
>
>    X12 X9 X10
> s1    0  1   0
> s2    0  0   0
> s3    0  1   0
> s4    0  0   0
>       s1        s2        s3        s4
> 0.3333333 0.0000000 0.3333333 0.0000000
>
>    X10 X18 X8
> s1    0    0  0
> s2    0    0  0
> s3    0    0  0
> s4    0    1  1
>  s1        s2        s3        s4
> 0.0000000 0.0000000 0.0000000 0.6666667
>
> This is the code I used:
>  for(i in 1:5)
>  {
>   temp<-sample(A3,3, replace=F)
>   Avg=rowMeans(temp)
>   show(temp)
>   show(Avg)
>  }
>
> Now, the problem is how can I save the result for each row(s1,s2,s3,s4) so
> that I can get the grand average from 5 runs?I thought about using a vector
> in the "for" loop but it's no good, it over right so basically I only get
> the means for last sample. any idea how to do it?
> Thanks a lot
>
> --
> View this message in context:
> http://www.nabble.com/saving-result-of-a-%22for%22-loop-tp20013519p20013519.html
> Sent from the R help mailing list archive at Nabble.com.
>
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>

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