I haven't digested everything in this thread yet but I can't wait to tell everyone about my discovery.

In Brook6's original post, he/she mentioned about wanting to use INDEX and MATCH. Brook6, I am late but here is the formula, an alternative to MAX, ROW etc. Please note that this is an array formula (CSE).

{=INDEX(A2:A4,MATCH(TRUE,MMULT(--(B2:F4=A7),TRANSPOSE(COLUMN(B2:F4)^0))0,0))}

I can't remember which smart person came up with the above formula. Biff, was that you? I just changed the cell reference and tested the formula and it gave the exact same results as the MAX/ROW formula if the item is found. If not found, MAX/ROW formula gives a blank whereas INDEX/MATCH gives #N/A. I don't know which formula is more efficient. Both are array formulae. For MAX/ROW we have to do a logical test each time whereas INDEX/MATCH has to go through MMULT, TRANSPOSE etc.

The truth is I don't know how to decipher this INDEX/MATCH formula as MMULT always drives me crazy. I must thank Kevin for telling me about MAX/ROW. I may not have fully analyzed it yet but at least it may be something that I can grasp. If I have a choice in setting up the database/array, I'll probably just use the KIS method (i.e. one to one - writing device pen, writing device pencil, writing device marker etc.) and then use VLOOKUP. I have a feeling that this is not as hard on the resource if we have a large array. Bob, please correct me if I am wrong. (Ignore me, Brook6, I am just trying to learn, not criticizing.)

I feel like showing an alternative formula in this thread for all the readers. Thank you for your attention.

Epinn

"Bob Phillips" wrote in message ...


"Epinn" wrote in message
...

Bob, it is a cinch for you to point out the header problem. Kevin uses
A1:A3 in the original formula. If there is a header on row 1, we can't
just shift A1:A3 to A2:A4. We have to subtract MIN(ROW( and add on
1 etc. Am I understanding this correctly?


No, not really. All we need to do is subtract 1 to account for the one
header row. BUT ... should there be 2 header rows, you subtract 2, etc. I
just use

-MIN(A2:A4)+1

as if the OP is adjusting later, he will see the same range repeated, and
adjust that as well. Makes the formula more generic, without a hard-coded
value.


This reminds me of Biff's
formula (see below) the other day. So, I take a look again. Viola! It
is
similar. There is a header row and there is INDEX, therefore manipulation
of row numbers. I just realize that MIN is used to make it more dynamic
and we can hardcode ROW(A$2)+1, right?


Again, not quite. I just feel that by repeating the whole range it makes it
more obvious later when changing. Sometimes when something like ROW(A2) is
used that may be because we want to use the row as an index starting at two,
and therefore may not need changing if the range is changed. ROW(A2:A4)
returns an array, so MIN is used to extract the first value.


See, I told you all I don't want to
compartmentalize when I learn. I guess INDEX and header row issue can
really "stay" in my system now. By the way, I have yet to figure out the
role of
SMALL ( ) in the following formula. I have a post (last one) for the
thread by
Jared on Sept. 21 "how to make a(n) function to list all the same
records."
Hopefully I can resolve it later.

=IF(ROWS($1:1)<=COUNTIF($A$2:$A$10,$A$15),INDEX(B$ 2:B$10,
SMALL(IF($A$2:$A$10=$A$15,ROW(A$2:A$10)-ROW(A$2)+1),ROWS($1:1))),"")


Biff is building an array of row numbers that meet the criteria. SMALL is
used to get the first matching row number, then the second, then the third,
etc. (Not the ROWS($1:1))


Back to this thread. I am wondering if this kind of array formula INDEX,
MAX, ROW can be a drag on the system if we have a large table. I know
VLOOKUP can be hard on the system too. Please correct me if I am wrong.


Any formula can be a drag on the system if used a lot, but array formulae
are particulalrly hard.


VLOOKUP will stop searching when it has found the first exact match and
uses the first value obtained when there are duplicates. In the contrary,
this INDEX/MAX/ROW array formula will go through the entire table
regardless;
and as Roger explains, it will pick up the last value if more than one
match.
Also, it will do a logical test each time before it can even perform the
INDEX
portion of the formula. So, I have a concern on performance/speed.
Do I worry too much?


No, it is a justifiable concern. But in this casek, it is working on a very
samll array, so it shouldn't matter.

And there are always ways to speed a spreadsheet up.


Bob, I told you I could make evaluate formula crash. I used Biff's
formula
above to make it crash and he did warn us. I have to let you know that
the previous crash was nothing compared to the crash caused by the
formula on this thread. I wonder if the (evaluate formula) crash is any
indication of the formula's impact on the resource when we press F9.


I wouldn't have thought so.