[R] `bivariate apply'

[Peter Wolf]

Vito Muggeo wrote:

>dear all,
>
>Given a matrix A, say, I would like to apply a bivariate function to each
>combination of its colums. That is if
>
>myfun<-function(x,y)cor(x,y) #computes simple correlation of two vectors x
>and y
>
>then the results should be something similar to cor(A).
>
>I tried with mapply, outer,...but without success
>
>Can anybody help me?
>
>many thanks in advance,
>vito
>
>______________________________________________
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>  
>
what about

myfun<-function(x,fun=cor){
 cl<-matrix(1:ncol(x),ncol(x),ncol(x))
 cl<-cbind(as.vector(cl),as.vector(t(cl)))
 res<-apply(cl,1,function(xx)fun(x[,xx[1]],x[,xx[2]]))
 matrix(res,ncol(x),ncol(x))
}

Peter Wolf