Thanks vezerid,

You make a very good point i did not consider.

I wanted to exclude zero values for Y (which i consider anomolies in the
dataset). However this cannot work as each number of variables in x and y
needs to be equal (corresponding).

x in my dataset is an independant variable being time which is measured as
the period being 1 to 24. The data for y is also 24 values but contain zero's.

If y is found to be zero I figure now I will need to also exclude to
corresponding Y value for that data point (which will not be zero).

Can this be done?

Bruce

"vezerid" wrote:

You want to exclude entries when BOTH x and y are 0? When either is 0?
Given the nature of the RSQ function this might not make much sense...

But anyway, just replace J11:AG11 with IF($J11:$AG11<0,$J11:$AG11) in
your formula.

HTH
Kostis Vezerides