[R] looking for 'tied rows' in dataframe

[Evan Cooch]

Suppose I have the following sort of structure:

test <- matrix(c(2,1,1,2,2,2),3,2,byrow=T)

What I need to be able to do is (i) find the maximum value for each row, 
(ii) find the column containing the max, but (iii) if the maximum value 
is a tie (in this case, all numbers of the row are the same value), then 
I want which.max (presumably, a tweaked version of what which.max does) 
to reurn a T for the row where all values are the same.

Parts (i) and (ii) seem easy enough:

apply(test,1,max)  --- gives me the maximum values
apply(test,1,which.max) --- gives me the column

But, standard which.max doesn't handles ties/duplicates in a way that 
serves my need. It defaults to returning the first column containing the 
maximum value.

What I'd like to end up with is, ultimately, something where 
apply(test,1,which.max) yields 1,2,T  (rather than 1,2,1).

So, a function which does what which.max currently does if the elements 
of the row differ, but which returns a T (or some such) if in fact the 
row values are all the same.

I've tried a bunch of things, to know avail. Closest I got was to use a 
function to test for whether or not a vector

isUnique <- function(vector){
                  return(!any(duplicated(vector)))
             }

which returns TRUE if values of vector all unique. So

apply(test,1,isUnique)

returns

[1]  TRUE  TRUE FALSE

but I'm stuck beyond this.  Suggestions/pointers to the obvious welcome.

Thanks in advance.