R help - Oct 2008 - Help with functions

Hi there,

I have a the following function which takes a  name(fname), total number of
rows (Total), number of times to make a sample(nSample), number of
records/rows to be included in each sample(nPatient). then it generates
required samples and calculates the mean and standard deviation of the
columns for each sample and finally in calculates the grand mean and
standard deviation. 

The problem is if I run each line of the code separately (not in a function)
it works but when I put it in a function it doesn't!!!

i.e. if I delete the first line, and put "Mydata"(where ever I have
fname)
and 900(where ever I have Total) and 5 (where ever I have nSample) and 100
(where ever I have nPatient) and run each line separately it works fine. But
when I make a function like the one below and call it like:
sampling(Mydata,900,5,100)
I get this error message: 
"Error in dimnames(x) <- dn : length of 'dimnames' [2] not equal
to array
extent"

I used "debug" on the sampling function it seems the error comes from
line
4: 
"result=replicate(nSample,trans[,sample(colnames(trans),nPatient)],simplify=FALSE)"

any idea why do I get this error and how to fix it?
Thanks,

sampling=function(fname,Total,nSample,nPatient){
trans=t(A)
colnames(trans) <- c(1:Total)
result=replicate(nSample,trans[,sample(colnames(trans),nPatient)],simplify=FALSE)
show(result)

Means=do.call(rbind,lapply(result,function(x) rowMeans(x)))
rownames(Means)=paste('sample',1:nSample,sep="")
show(Means)
Gmean=colMeans(Means)
Gmean

# load genefilter package
STDs=do.call(rbind,lapply(result,function(x) rowSds(x)))
rownames(STDs)=paste('sample',1:nSample,sep="")
show(STDs)
Gsd=sd(STDs)
Gsd

return(Gmean,Gsd)}
-- 
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Hi,

A repeatable example with data would help, as that way we could
see what was happening.
>
> sampling=function(fname,Total,nSample,nPatient){
> trans=t(A)
What's A? It isn't one of the arguments to your function.
And what's the transpose of a non-existent thing?

You may well have it in your workspace so the function goes when you
copy and paste in the code.

Sarah

-- 
Sarah Goslee
http://www.functionaldiversity.org

It might be your return statement.  Look up 'return' in the help file
and you will see that you can only return a single value.  If you want
multiple values returned, use a list:

return(listGmean,Gsd))

On Wed, Oct 22, 2008 at 11:53 AM, Alex99 <loyola9988 at yahoo.com>
wrote:
>
> Hi there,
>
> I have a the following function which takes a  name(fname), total number of
> rows (Total), number of times to make a sample(nSample), number of
> records/rows to be included in each sample(nPatient). then it generates
> required samples and calculates the mean and standard deviation of the
> columns for each sample and finally in calculates the grand mean and
> standard deviation.
>
> The problem is if I run each line of the code separately (not in a
function)
> it works but when I put it in a function it doesn't!!!
>
> i.e. if I delete the first line, and put "Mydata"(where ever I
have fname)
> and 900(where ever I have Total) and 5 (where ever I have nSample) and 100
> (where ever I have nPatient) and run each line separately it works fine.
But
> when I make a function like the one below and call it like:
> sampling(Mydata,900,5,100)
> I get this error message:
> "Error in dimnames(x) <- dn : length of 'dimnames' [2] not
equal to array
> extent"
>
> I used "debug" on the sampling function it seems the error comes
from line
> 4:
>
"result=replicate(nSample,trans[,sample(colnames(trans),nPatient)],simplify=FALSE)"
>
> any idea why do I get this error and how to fix it?
> Thanks,
>
> sampling=function(fname,Total,nSample,nPatient){
> trans=t(A)
> colnames(trans) <- c(1:Total)
>
result=replicate(nSample,trans[,sample(colnames(trans),nPatient)],simplify=FALSE)
> show(result)
>
> Means=do.call(rbind,lapply(result,function(x) rowMeans(x)))
> rownames(Means)=paste('sample',1:nSample,sep="")
> show(Means)
> Gmean=colMeans(Means)
> Gmean
>
> # load genefilter package
> STDs=do.call(rbind,lapply(result,function(x) rowSds(x)))
> rownames(STDs)=paste('sample',1:nSample,sep="")
> show(STDs)
> Gsd=sd(STDs)
> Gsd
>
> return(Gmean,Gsd)}
> --
> View this message in context:
http://www.nabble.com/Help-with-functions-tp20113920p20113920.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?