Herbert Seidenberg wrote:
Smartin:
Since we want combinations, not permutations,
half of the array has been set to zero with the term
(c_1 Rc_2 C) (using R1C1 ref designations)
The diagonal is zero by definition.
I am using features of Excel 2007 that do not easily
translate into Excel 2003.

Ah! Makes sense. Thanks for the explanation.

If I could engage you a little further, is the use of complex numbers a
convenience, or could this have been accomplished just as well using the
"usual" way of computing the distance between points

=sqrt((y2-y2)^2+(x2-x1)^2)

....Never mind, I think I answered that one myself.

Ok, what's confusing me is the R1C1 syntax. Any pointers?