Hi,

I would like to evaluate a function f(x,y) taking two vectors as  
entries on all pairs of X rows and Y rows, where X and Y are n-by-p  
and m-by-p matrices respectively.  Of course, I would like to avoid  
loops if possible, as the dataset I want to process is quite large.   
I was not able to find a combination of outer() and apply() to do  
this -- note that I am fairly new to R.  Below is a simple example of  
what I would like to do -- for illustration purposes only, as I am  
not interested in this particular function.

X = matrix(sample(1:3,size=15,replace=TRUE),5,3)
Y = matrix(sample(1:3,size=10,replace=TRUE),5,3)

f = function(x,y) {
	max(x/y)
	}

A = matrix(0,5,5)
	
for (i in 1:5) {
	for (j in 1:5) {
		A[i,j] = f(X[i,],Y[j,])
		}
	}

Thanks for your help.

Ery Arias-Castro
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