how does this formula work: =LOOKUP(2,1/((COUNTIF(D6:D41,""&D6:D41)=0)*(D6:D41<"")),D6:D 41)
I see what you mean.
When I was testing this the first time around it didn't seem to make a
difference with empty cells unless all the cells were empty. Obviously I
didn't test it enough! Of course, if there will be no empty cells then we
don't have to worry about that.
Also note that the formula is written on the assumption that there is only
*text* in the range. No formula blanks, either! And this all leads to the
question: Just how robust does this need to be? Only the OP knows the answer
to that question.
--
Biff
Microsoft Excel MVP
"Bernard Liengme" wrote in message
...
This is simply testing to make sure the cells are not blank. You may not
need that for your application but I put it in there out of habit!
There's really no difference with it or without it except when every cell
in the range is blank.
Biff,
I did an experiment with
=LOOKUP(2,1/((COUNTIF(D6:D12,""&D6:D12)=0)*(D6:D12<"")),D6:D 12)
and
=LOOKUP(2,1/((COUNTIF(D6:D12,""&D6:D12)=0)),D6:D12)
With test data: A, B, C, D, A, B, C both gave D as expected
With just one blank the first still gave D but the second gave 0: but
sometimes it did give the right result - very odd
all the best
--
Bernard
"T. Valko" wrote in message
...
A little known fact about COUNTIF is that it evaluates TEXT for equality
the same way it evaluates numbers.
A
B
D
C
=COUNTIF(A1:A4,"A") = 3
=COUNTIF(A1:A4,"D") = 0
You wanted to return the "largest" text entry in the range.
=LOOKUP(2,1/((COUNTIF(D6:D41,""&D6:D41)=0)*(D6:D41<"")),D6:D 41)
Here's how the formula works...
In the above formula LOOKUP uses 3 arguments:
lookup_value = 2
lookup_vector = 1/((COUNTIF(A1:A4,""&A1:A4)=0)*(A1:A4<""))
result_vector = A1:A4
Let's dissect the lookup_vector...
Since we want the largest text entry we "know" that the largest text
entry will have a COUNTIF result of 0 meanng there are no entries greater
than the largest text entry. See the COUNTIF formula above.
The COUNTIF will return an array of results:
COUNTIF(A1:A4,""&A1) = COUNTIF(A1:A4,"A") = 3
COUNTIF(A1:A4,""&B1) = COUNTIF(A1:A4,"B") = 2
COUNTIF(A1:A4,""&C1) = COUNTIF(A1:A4,"D") = 0
COUNTIF(A1:A4,""&D1) = COUNTIF(A1:A4,"C") = 1
We then test these results for equality to 0:
COUNTIF(A1:A4,"A") = 3 = 0 = FALSE
COUNTIF(A1:A4,"B") = 2 = 0 = FALSE
COUNTIF(A1:A4,"D") = 0 = 0 = TRUE
COUNTIF(A1:A4,"C") = 1 = 0 = FALSE
This array is then multiplied together with this array: (A1:A4<"")
This is simply testing to make sure the cells are not blank. You may not
need that for your application but I put it in there out of habit!
There's really no difference with it or without it except when every cell
in the range is blank.
(A1<"") = TRUE
(B1<"") = TRUE
(C1<"") = TRUE
(D1<"") = TRUE
{F;F;T;F}*{T;T;T;T} ={0;0;1;0}
Ok, now comes the confusing part!!!
The way that LOOKUP works is:
If the lookup_value is greater than any value in lookup_vector, it will
match the *last* value in the lookup_vector that is less than the
lookup_value. The lookup_value is 2 and the lookup_vector is 0;0;1;0. The
lookup_value 2 *IS* greater than any value in the lookup_vector so it
will match the *last* value in the lookup_vector that is less than 2 and
that value is the last 0.
Now comes the really confusing part!!!
The *last* value that is less than the lookup_value 2 is the *last* 0.
However, this can't be our match since 0 means this entry failed to meet
the conditions of the COUNTIF=0 and/or the test for blank. So, we need to
do something about that.
LOOKUP ignores error values so we are going to use that to our advantage.
We divide 1 by the the array {0;0;1;0} knowing that any number divided by
0 returns the #DIV/0! error. So:
1/0 = #DIV/0!
1/0 = #DIV/0!
1/1 = 1
1/0 = #DIV/0!
So that becomes the array for the lookup_vector (D=#DIV/0!):
{D;D;1;D}
Now, the *last* value in the lookup_vector that is less than the
lookup_value 2 is 1.
So the final result of the formula is the entry in the result_vector
which is the range A1:A4 that corresponds to 1.
=LOOKUP(2,{D;D;1;D},{"A";"B";"D";"C"})
=D
D is the largest TEXT entry in the range.
So there you have it!
exp101
--
Biff
Microsoft Excel MVP
"Dave F" wrote in message
...
Can someone please explain to me what this formula is doing?
=LOOKUP(2,1/((COUNTIF(D6:D41,""&D6:D41)=0)*(D6:D41<"")),D6:D 41)
Thanks.
Dave
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