[R] How to pool a group of samples and take the ave.

[jim holtman]

you can use 'apply':

apply(A[, 48:243], 1, median)

On Nov 12, 2007 3:30 PM, affy snp <affysnp at gmail.com> wrote:
> Thanks Jim. It is way simple. Great.
> Is there any function like rowMedians() which
> could take the median value across samples?
>
> Allen
>
> On Nov 12, 2007 3:10 PM, jim holtman <jholtman at gmail.com> wrote:
>
> > Try something like this:
> >
> > myAvg <- rowMeans(A[,48:243])
> > B <- A[1:47,] / myAvg
> >
> >
> > On Nov 12, 2007 1:37 PM, affy snp <affysnp at gmail.com> wrote:
> > > Dear list,
> > >
> > > Hi! I have a table A, 238304 rows and 243 columns (representing
> > > samples). First of all, I would like to pool a group of samples
> > > from 48th column to 243rd column and take the average across
> > > them and make a single column,saying as the reference column.
> > >
> > > Second, I want to use each column of first 47 columns in table
> > > A divided by the reference column and end up with a new table
> > > B with 238304 rows and 47 columns.
> > >
> > > Is there any simple code which especially could do sth like
> > >       reference_column<-(A[,48]+A[,49]+...A[,243])/196
> > > and B<-A[,1:47]/reference_column?
> > >
> > > Thank you very much for your help!
> > >
> > > Best,
> > >      Allen
> > >
> > > ______________________________________________
> > > 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 you are trying to solve?
> >
>



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

What is the problem you are trying to solve?