[R] The most common row in a matrix?

[Atte Tenkanen]

Hi Gabor,

Your version works with the small sample matrix but I didn't get it to work with a larger 675x8 -matrix. I don't know why. I don't know the command aggregate if there is something.
I got this one from Peter Alspach

which.max(table(paste(data.frame(t(MATRIX)), sep=',')))

and it seems to work as well as one posted by Dimitrios Rizopoulos.

Atte

> Try this:
> 
> a <- matrix(1:3, 4, 5)
> 
> a.ag <- aggregate(1:nrow(a), as.data.frame(a), length)
> a.ag[which.max(a.ag$x), 1:ncol(a)]
> 
> 
> On 11/19/06, kone <attenka at utu.fi> wrote:
> > Hi,
> >
> > How do you get the most common row from a matrix? If I have a matrix
> > like this
> >
> > array(1:3,dim=c(4,5))
> >
> >      [,1] [,2] [,3] [,4] [,5]
> > [1,]    1    2    3    1    2
> > [2,]    2    3    1    2    3
> > [3,]    3    1    2    3    1
> > [4,]    1    2    3    1    2
> >
> > in which rows 1 and 4 are similar, I want to find that vector c
> > (1,2,3,1,2).
> >
> > Atte Tenkanen
> > University of Turku, Finland
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch 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.
> >
>