Comments on: Power Formulas for Unique Data

By: Daniel Skinner

Daniel Skinner — Mon, 06 Jun 2011 11:58:00 +0000

@Eugene: Try this: Replace all calls to ROW(Table1[Name]) with ROW(Table1[Name])-SMALL(ROW(Table1[Name]),1)+1

@Belarbi: Trying to get data validation working to. What is the reason for this failing when trying to use data validation?

By: Belarbi

Belarbi — Sun, 25 Apr 2010 21:20:00 +0000

Good work.
But how could this technique used to populate a combobox with TheUniqueArray
Regards

By: Primo

Primo — Tue, 01 Jul 2008 15:28:00 +0000

Vera

If you've copied the formulas directly from the web page you'll need to change the quotes in "1:" because they're a different character and they don't work in the Excel formula. I think all the other quotes are correct.

Also, if you've defined your list as starting from a row other than row one (you've mentioned B2) then you're going to need some adjustments to the other formulas.

By: Vera

Vera — Fri, 27 Jun 2008 17:17:00 +0000

What am I doing wrong, because these don't work:

because ("'Sheet1'!B2:B"or this because "1:"

=SMALL(IF(MATCH(TheList,TheList,0)=ROW(TheList),ROW(TheList),""),
ROW(INDIRECT("1:"&SUM(N(MATCH(TheList,TheList,0)=ROW(TheList))))))-1

Thanks

By: fzz

fzz — Sat, 12 Apr 2008 22:17:00 +0000

Pivot tables don’t update automatically. Refresh is nice, but it’s manual. Pivot tables also require field labels in the top row, they span at least 2 columns, and you can’t always ensure the original order is reproduced.

By: Scott Doyschen

Scott Doyschen — Fri, 11 Apr 2008 00:56:00 +0000

Why not just use a pivot table to determine the unique values and the count of each unique value? It’s simple and quick, and it will also update as you add more data to the original listing – all you have to do is refresh the results.

By: Eugene

Eugene — Tue, 04 Dec 2007 14:55:00 +0000

I am having a surprising amount of trouble trying to adjust this method to account for a header row… Could someone please explain how they would go about it?

By: Dick Kusleika

Dick Kusleika — Thu, 28 Dec 2006 22:22:00 +0000

Where did you think I got my posting ideas?

By: fzz

fzz — Thu, 28 Dec 2006 22:02:00 +0000

How about checking the newsgroups. This has been answered several times over the years.

Anyway, lots of OFFSET calls (or other volatile function calls) always kills performance.

If the result would be used as a term in longer formulas, there may be better alternative formulas that don't require such an array. If the result would populate another range, there's a much better alternative that doesn't call any volatile functions.

Define TheList as
=$A$1:INDEX($A:$A,COUNTA($A:$A))

Topmost cell (make it C1)
=INDEX(TheList,1)

Next cell (C2)
=INDEX(TheList,MATCH(0,COUNTIF(C$1:C1,TheList),0))

The last is an array formula. Fill the last formula down as far as needed. The filled formulas may also take a long time to calculate the first time, but they won't recalculate every time anything triggers recalculation.

There are newsgroup postings with this technique at least as far back as 2000. There were likely even older postings, but Google doesn't seem to do well with the Deja News archive they bought.

Nice to know the blogger finally reinvented this wheel.

By: Dan Hatola

Dan Hatola — Thu, 28 Dec 2006 18:21:00 +0000

Forgot to mention it, but this solution only works with numerical data...

Dan