IF just STOPS WORKING

"Gee" wrote:
OK, all that said and my subsequent confusion, I never had a problem
with this kind of thing in '03, only in '07 and I'm still working on
another
problem with it but the 13 decimal places solved the Yes/No problem
just fine. Thanks so much for your help.

No thanks is warranted, at least not to me. I feel quite guilty insofar as
I have become complicit in your false sense of security. I have tried to
explain repeatedly that I have offered no solution to a problem because I
still do not know what the problem is.

If there is a difference related to '07 v. '03, I suspect it might be in the
database application (Access?) -- or perhaps it is merely a schema change
that occurred during the transition by coincidence.

David says there are differences in the way that Excel interprets arithmetic
results. I'll take his word for it. But if there is a difference, any
changes you made (I don't know what they are) might simply have hidden the
problem or made it less likely, but not impossible, to occur.

It is unclear to me how you used the "suggestion" (not!) to format to "13"
(should be 12) decimal places and why you think it solved any problem. I
can only ass-u-me that you mean that it changed your perception of the
values and, hence, your expectation of the result of the Yes/No IF()
formula.

But I really must stop myself from making wild speculation (WAGs); it only
contributes to the confusion here. You continue to offer insufficient
details for even an intelligence guess as to what the problem is, much less
how to solve it. However, I am curious. So if you post here again, it
would be nice if you provided a concrete example that demonstrates how
formatting to "13" decimal places seemed to have solved the problem -- and
what you mean by "solved".


----- original message -----

"Gee" wrote in message
...
OK, all that said and my subsequent confusion, I never had a problem with
this kind of thing in '03, only in '07 and I'm still working on another
problem with it but the 13 decimal places solved the Yes/No problem just
fine.
Thanks so much for your help.

If you know anything about Excel VBA Programming, I'm having another
problem
with this project...It's under Excel Programming and the topic is "Sending
3
email?". You guys are good...I'd appreciate if you could give me some
input
on this very last hurdle.


"JoeU2004" wrote:

PS....


I wrote:
"David Biddulph" groups [at] biddulph.org.uk wrote:
or to
=if(and(HI2=400.5,HI2402.5), "YES", "NO")
[....]
People should learn not to compare with numbers with
decimal fractions, since most decimal fractions are
not exact internally. They will inevitably get a
surprising result.

But using ROUND in comparisons with numbers with decimal fractions is
okay,
when done correctly. For example:

=if(and(400.5=round(HI2,1),round(HI2,1)402.5), "YES", "NO")

This is okay because ROUND ensures that the internal binary
representation
of its result exactly matches a constant with the same number of decimal
places. For example, if A1 is =10.1-10, =(A1=0.1) returns FALSE, but
=(round(A1,1)=0.1) returns TRUE. The reason is: the binary
representation
of 10.1-10 is not close enough to the binary representation of the
constant
0.1 for Excel to consider them equal.

In contrast, if A1 is =0.1+2^-56, =(A1=0.1) returns TRUE even though the
binary representations of A1 and 0.1 are not the same. Likewise, =A1-0.1
returns zero. But =(A1-0.1) returns non-zero, namely about 1.39E-17.
And
=IF(A1-0.1=0,TRUE) returns FALSE, which flies in the face of reason
considering the result of =A1-0.1, until we understand Excel's dubious
heuristic for determining "close enough".

But I digress....


----- original message -----

"JoeU2004" wrote in message
...
"David Biddulph" groups [at] biddulph.org.uk wrote:
=if(and(401=round(HI2,0),round(HI2,0)=402), "YES", "NO")
would presumably be equivalent to
=if(or(round(HI2,0)=401,round(HI2,0)=402), "YES", "NO")

Yes, I thought of that, too. I chose not to mention it because I did
not
want to confuse Gee anymore that he/she already seems to be. I chose
the
more-general numeric range test because I wondered if integer limits
are
really what Gee wants/needs.


or to
=if(and(HI2=400.5,HI2402.5), "YES", "NO")

I disagree, especially considering Gee's continued confusion between
displayed and actual values. Depending on formatting, a cell might
display as 400.5 (expect "YES"), but it is actually 400.49 (resulting
in
"NO").

People should learn not to compare with numbers with decimal fractions,
since most decimal fractions are not exact internally. They will
inevitably get a surprising result.


----- original message -----

"David Biddulph" groups [at] biddulph.org.uk wrote in message
...
=if(and(401=round(HI2,0),round(HI2,0)=402), "YES", "NO") would
presumably be equivalent to
=if(or(round(HI2,0)=401,round(HI2,0)=402), "YES", "NO") or to
=if(and(HI2=400.5,HI2402.5), "YES", "NO")
if either of those helps the OP to see whether that's what he wants.

[I have changed your H12s to the OP's HI2 reference.]
--
David Biddulph

"JoeU2004" wrote in message
...
"Gee" wrote:
I thought it might be something like that. I changed the columns
to no decimal places, but since it was getting data from an external
database it might have caused the problem.
It's working right now...if it stops I'll be back!

I think you missed the point. Changing the format only changes the
appearance of the cell value; it does not change the actual value.
WYSI(not)WYG!


You wrote previously:
=IF(AND(HI2401,HI2402),"YES","NO")

If you are happy with displaying H12 with zero decimal places, it is
no
longer clear what your intent is with the AND() expression above.

I suspect you want:

=if(and(401=round(H12,0),round(H12,0)=402), "YES", "NO")


----- original message -----

"Gee" wrote in message
...
I thought it might be something like that. I changed the columns to
no
decimal places, but since it was getting data from an external
database
it
might have caused the problem.
It's working right now...if it stops I'll be back!
Thank you SO much for the help! I was really in a corner.


"JoeU2004" wrote:

"Gee" wrote:
Why has this worked for about 3 hours and then suddenly stopped??

Define "working".


=IF(AND(HI2401,HI2402),"YES","NO")

It probably has nothing to do with time of day, unless the value in
H12 is
derived from time of day (i.e. NOW()).

More likely, the value in H12 is not what it appears to be. For
example, if
the value is 401.00001, it might be displayed as 401, so you might
expect
"NO". But AND(401H12,H12402) returns TRUE, so you actual get
"YES".

If that is not enough to help you, post again with details, namely
the
formula and value in H12, formatted to 13 decimal places.


----- original message -----

"Gee" wrote in message
...
Why has this worked for about 3 hours and then suddenly stopped??

Excel 2007 is what I'm using

=IF(AND(HI2401,HI2402),"YES","NO")

Thank you in advance for any help you can give me.

"David Biddulph" groups [at] biddulph.org.uk wrote:
Excel 2007 has different ways of guessing whether a
difference is zero. It's one of its known problems,
and you'll see frequent reports in the archives of
this and other excel newsgroups.

Oh? I do not remember seeing any threads where the root cause was found to
be a difference in the way that Excel 2007 interprets arithmetic results.
Can you point me to one, for my edification?

I do remember many threads related to some functions (XIRR, NPV, YIELD, even
EDATE!) returning errors reportedly in Excel 2007, but not in Excel 2003,
allegedly with no changes other than to open the workbook in Excel 2007. I
do not believe the root cause was ever agreed upon. For example, see
http://www.google.com/url?url=http:/...0NeOfRxIe2h2jg .

Is that you're thinking of?

I'm not trying to impugn your statement. I'm just very curious about this,
having spent a lot of time reverse-engineering the dubious heuristic as it
is implemented in Excel 2003.


----- original message -----

"David Biddulph" groups [at] biddulph.org.uk wrote in message
...
Excel 2007 has different ways of guessing whether a difference is zero.
It's one of its known problems, and you'll see frequent reports in the
archives of this and other excel newsgroups.
--
David Biddulph

"Gee" wrote in message
...
OK, all that said and my subsequent confusion, I never had a problem with
this kind of thing in '03, only in '07 and I'm still working on another
problem with it but the 13 decimal places solved the Yes/No problem just
fine.
Thanks so much for your help.

...

"JoeU2004" wrote:
...
But using ROUND in comparisons with numbers with decimal fractions is
okay,
when done correctly. For example:

=if(and(400.5=round(HI2,1),round(HI2,1)402.5), "YES", "NO")

This is okay because ROUND ensures that the internal binary
representation
of its result exactly matches a constant with the same number of decimal
places. For example, if A1 is =10.1-10, =(A1=0.1) returns FALSE, but
=(round(A1,1)=0.1) returns TRUE. The reason is: the binary
representation
of 10.1-10 is not close enough to the binary representation of the
constant
0.1 for Excel to consider them equal.

In contrast, if A1 is =0.1+2^-56, =(A1=0.1) returns TRUE even though the
binary representations of A1 and 0.1 are not the same. Likewise,
=A1-0.1
returns zero. But =(A1-0.1) returns non-zero, namely about 1.39E-17.
And
=IF(A1-0.1=0,TRUE) returns FALSE, which flies in the face of reason
considering the result of =A1-0.1, until we understand Excel's dubious
heuristic for determining "close enough".
...