Comments on: Union and Intersect

By: Tushar Mehta

Tushar Mehta — Wed, 01 Jul 2009 01:52:00 +0000

Ed: Check the SubtractFirstPrinciples function at http://www.dailydoseofexcel.com/archives/2007/08/17/two-new-range-functions-union-and-subtract/

You can use it as in =SUM(SubtractFirstPrinciples(A:A,A1)) though it is quite slow if you give it an entire column in 2007.

By: Ed Ferrero

Ed Ferrero — Tue, 30 Jun 2009 04:09:00 +0000

So, if we define a named range NotFirst =Sheet1!$2:$65536,
then we can use a formula in cell A1 like this
=SUM((C:C) NotFirst)
to sum the whole of column C without getting a circular reference.

It's a shame that there is no inverse of a range operator in Excel.
Something that would let me specify =NOT(A1,A:A) and return A2:A65536.

No clever comments about the number of rows in 2007, thanks.

By: Rob van Gelder

Rob van Gelder — Mon, 21 Jul 2008 23:52:00 +0000

Benny
You may be correct, but Union is the label as assigned by Microsoft.

ptgIsect: Intersection (ptg=0Fh)
Computes the intersection of the top two operands. This is the Excel space operator.

ptgUnion: Union (ptg=10h)
Computes the union of the top two operands. This is the Excel comma operator.

ptgRange: Range (ptg=11h)
Computes the minimal bounding rectangle of the top two operands. This is the Excel colon operator.

By: Benny

Benny — Mon, 21 Jul 2008 14:52:00 +0000

This is an informative page, with almost maliciously incorrect terminology.
The [space] character is, indeed, an "intersect operator."
The [comma] character is IN NO WAY a mathematical "union operator." It is in fact "set addition," which SQL calls "union all."

A union returns a SET (in this case, a SET of cells). Set Addition returns a MULTISET. The comma is Set Addition, because using Comma with the same cell twice returns TWO (of the same) cell. For instance:
3=COUNT(C2,C2,C2)=COUNT((C2,C2,C2))
If comma were really a union operator, these counts would return 1!
A less useless example is taking a "plus" shaped range:
6=COUNT(F4:H4,G3:G5)
Obviously, that plus-shaped range has 5 cells. Cell G4 is counted twice, PRECISELY because the comma-character is NOT a union operator.

How sad, that Excel does not support mathematical union (without using VBA).
-b

By: Jim

Jim — Fri, 02 Dec 2005 02:22:00 +0000

This looks like it has a lot of potential for me. I have created named ranges which represent columns of unique parameters, and named ranges which represent groups of rows to partition the source of the data. What I would like to do is copy the several cells which are the interseection of the parameter range with a particular group of rows. I.e. column AB is named param1 and rows 10 to 20 are named datasetA and are several readings I want to do some computing on. What I have been experimenting with, without success, is using something like:

intersect(range("param1?),range("datasetA")).copy worksheets("sheet2?).range("A1?)

Suggestions?
Thanks, Jim.

By: Rob van Gelder

Rob van Gelder — Fri, 04 Feb 2005 00:53:00 +0000

Jay,

Thanks Jay - nice spotting

=A1:A5, A8:A10 is valid, but always returns #VALUE!

A pseudo-union.

Rob

By: jay

jay — Thu, 03 Feb 2005 22:43:00 +0000

First, nice & useful blog - thanks!

Second, I'm not convinced the union operator is really an operator and not just a piece of microsoft rhetoric. I've never seen it used in a context where it couldn't ALSO be interpreted as a comma separating arguments (e.g., in a SUM function). For example, the following array formula, which uses an intersect operator, works:

{SUM(IF((A1:A10 A1:10)="a",1,0))}

whereas this one, which uses the so-called "union operator" returns a #VALUE! error

{SUM(IF((A1:A5,A6:10)="a",1,0))}

This is enourmously frustrating because an authentic union operator could be extremely useful when doing, e.g., complex database lookups.

By: Ola Sandstrom

Ola Sandstrom — Thu, 20 Jan 2005 01:40:00 +0000

Great!
Intersect by a blank separator is new to me. I'll definitly use it.

Ola

This is also new to me: http://www.nsl.com/k/excel.k

By: ross

ross — Tue, 18 Jan 2005 11:58:00 +0000

when i saw this, i started to thing about using Intersect with row and coloum, could be slow though.

By: Rob van Gelder

Rob van Gelder — Mon, 17 Jan 2005 21:40:00 +0000

I can't help but feel there is hidden potential with intersects. It looks very similar to a lookup.

The Operator Precedence orders Intersect before Union which is why I used a bracket.