=SUMPRODUCT((A1:A20<"")/COUNTIF(A1:A20,A1:A20&""))

--
HTH

Bob Phillips

"Richard Buttrey" wrote in
message ...
I have a column of data in the form

a
a
a
b
b
c
c

etc.,

I know I can run an Advanced unique filter to obtain a list of unique
values and then use a COUNTA function to count them, but is there a
single function that would return the result, i.e. 3 (a, b & c) given
the above data?

(apologies if this appears twice - I thought I had posted it directly
to the GoogleNews (Deja) site but it doesn't seem to have turned up.

Rgds
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Richard Buttrey
Grappenhall, Cheshire, UK
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