On the very useful site http://www.xldynamic.com/source/xld.SUMPRODUCT.html
there is a note that the arrays in SUMPRODUCT formulas must be the same
size. Sounds sensible enough.

But today when look at the post with subject "Why does this formula return a
#VALUE error", we have one array of 12 by 1 and another of 12 by 12.

I have been using the double negative method of converting Boolean to {0,1}
but if I try
=SUMPRODUCT(--(A1:F1="a"),A2:F3) I get a #VALUE error (note the 1 by 1 and
the 1 by 2 arrays)
But =SUMPRODUCT((A1:F1="a")*(A2:F3)) works!

So when is double negation (--) better than * (multiplication) ?

--
Bernard V Liengme
www.stfx.ca/people/bliengme
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