Multiplying non consecutive rows, than adding it.

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Hello,

I need your help here. I am trying to calculate a monthly progress of
planned vs. real. My "planned" formula is ok. The problem comes for the
"real" one.

Let's say I wanted to multiply the odd rows from D2:D63 * even rows from
B2:B63, then add the results. I have tried things like
=SUMPRODUCT((IF(MOD(ROW(D2:D63),2)=1,D2:D63,0)*IF(MOD(ROW(B2:B63),2)=0,B2:B63,0))) but it won't work, it will always display 0 as a result.

Odd rows from B2:B63 will be blank, and in D2:D63 we will have the "real"
progress on odd rows and "planned" progress on even rows.

I know it shouldn't be so difficult, but I'm stuck.

Thanks in advance.


Regards,

RF
 
I need your help here. I am trying to calculate a monthly progress of
planned vs. real. My "planned" formula is ok. The problem comes for the
"real" one.

Let's say I wanted to multiply the odd rows from D2:D63 * even rows from
B2:B63, then add the results. I have tried things like
=SUMPRODUCT((IF(MOD(ROW(D2:D63),2)=1,D2:D63,0)*IF(MOD(ROW(B2:B63),2)=0,B2:B63,0)))
but it won't work, it will always display 0 as a result.

Odd rows from B2:B63 will be blank, and in D2:D63 we will have the "real"
progress on odd rows and "planned" progress on even rows.
Click to expand...

Does this do what you are looking for?

=SUMPRODUCT((B2:B62)*(D3:D63))

assuming the match up for multiplication is the odd row from the "D" column
times the previous row in the "B" column.

Rick
 
WOW! That's it!

Thanks a LOT Toppers.

Now, if it wouldn't be much trouble... what was I doing wrong?


Regards,

RF
 
YAY!

This one works as well... I don't know why did I try building such a long
formula if a simple one like this does the job. As one of my orevious
teachers would say: "it's the elegant solution".

Thanks Rick.

Regards,

RF
 
Wait a minute... I am not so sure it does what you want anymore.

You said earlier that Toppers' solution worked for you. My formula does not
produce the same results as his. Which one produces the correct result for
you... Toppers' or mine? I can produce the same result as Toppers' formula
with a slight modification to the one I posted earlier...

=SUMPRODUCT((B2:B62)*(D3:D63)*MOD(ROW(D3:D63),2))

What it does (and what Topper's does)(and perhaps what you asked for when
you said "non-consecutive") is multiply only the odd rows in "D" by the even
rows in "B". That is decidedly different than what my original formula did,
which was to multiply EVERY row's value in "D" by the previous row's value
in "B".

I am not entirely sure what you actually were after, but you should study
the results from my two formulas, and Toppers' formula, to make sure you are
getting the result you really want.

Rick
 
Rick,

one of the drawbacks with your earlier formula (and with mine in
another thread) is that if the supposedly blank cells in column B
actually contained a space (or something else which made them look
blank), then the formula will return #VALUE as we are trying to
multiply text. I think Topper's solution (and your modification here)
is the safest approach.

Pete
 
one of the drawbacks with your earlier formula (and with mine in
another thread) is that if the supposedly blank cells in column B
actually contained a space (or something else which made them look
blank), then the formula will return #VALUE as we are trying to
multiply text.
Click to expand...

Notice in my first formula...

=SUMPRODUCT((B2:B62)*(D3:D63))

the ranges are offset from each other... theoretically, according to the
original data range, these offset ranges are never over a "blank" cell.

I think Topper's solution (and your modification here)
is the safest approach.
Click to expand...

But what is it that the RF wanted? Remember, my original formula produces a
completely different result than either Toppers' or my modification to
produce the same result as Toppers'... and yet the RF said both solved his
problem. Since that is not possible, I am left wondering what was really
needed.


Rick
 
Hi Rick,

Well surprisingly, and maybe because of particular conditions on my sheet,
Topper's and yours both return the same output. I tried the other one you
suggest and it works too. I will change the values to study their reactions.

What I definitely need the formula to do is multiply every odd row in D2:D63
* every even row in B2:B63, then add the results. I think it is almost the
same as what you stated earlier:

To clarify, I need: =D3*B2+D5*B4+D7*B6+....

Thanks.

RF
 
Well surprisingly, and maybe because of particular conditions on my sheet,
Topper's and yours both return the same output. I tried the other one you
suggest and it works too. I will change the values to study their
reactions.

What I definitely need the formula to do is multiply every odd row in
D2:D63
* every even row in B2:B63, then add the results. I think it is almost the
same as what you stated earlier:


To clarify, I need: =D3*B2+D5*B4+D7*B6+....
Click to expand...

Then I am pretty sure my original formula does not work for you. Here is the
test data I used...

COL ==> B D

ROW
=====
2 2 12
3 3 33
4 4 32
5 5 12
6 6 34
7 7 52
8 8 23
9 9 42

Hopefully, the layout for the data is readable. Here are the results I get
for the three formulas...

My 1st Formula - 1189

My 2nd Formula - 762

Toppers' Formula - 762

My first formula does NOT produce the result you are looking for.

Rick
 
Rick,

even though your ranges are offset from each other, your first formula
will produce B2*D3 + B3*D4 + B4*D5 etc. Now, B3*D4 should equal zero
as B3 should be blank, but what I pointed out earlier is that if B3
contains a space you will get #VALUE.

The formula can work with the OP's data if he has alternate blanks in
column B. In your test data you do not have alternate blanks, so you
are adding up too many values.

Here's an alternative array* formula which is "safe" from spurious
blanks:

=SUM(IF(MOD(ROW(B2:B62),2)=0,(D3:D63)*(B2:B62)))

*Commit with CSE.

Pete
 
even though your ranges are offset from each other, your first formula
will produce B2*D3 + B3*D4 + B4*D5 etc. Now, B3*D4 should equal zero
as B3 should be blank, but what I pointed out earlier is that if B3
contains a space you will get #VALUE.
Click to expand...

I assumed since the OP wanted to reach back to B2 (an even row) from D3 (an
odd row), that he would have data in these cells although I would expect D2
to probably be blank (sort of like a starting condition).
The formula can work with the OP's data if he has alternate blanks in
column B. In your test data you do not have alternate blanks, so you
are adding up too many values.
Click to expand...

Ahhh! (The light-bulb goes on<g>)... **that** is why my first equation
worked... there are alternating blanks in each row!!!

Rick
 
Hmm! I have been answering your questions here in this group while you are
running it over in m.p.e.worksheet.functions also. Something for you to
consider for the future...

From a post by Jeff Johnson:

"You have posted this question individually to multiple groups. This is
called Multiposting and it's BAD. Replies made in one group will not be
visible in the other groups, which may cause multiple people to respond to
your question with the same answer because they didn't know someone else had
already done it. This is a waste of time.

If you MUST post your message to multiple groups, post a single message and
select all the groups (or type their names manually in the Newsgroups field,
separated by commas) in which you want it to be seen. This is called
Crossposting and when used properly it is GOOD."

Some additional comment previously posted by me:

"You may not see this as a problem, but those of us who volunteer answering
questions on newsgroups do see it as a problem. You can't imagine how
annoying it is for a volunteer to read a question, research background
material, test sample code and then formulate and post an answer to the
original question only to go to another newsgroup and find the question
posted and ALREADY answered over there. On top of that, if you cross-post
your question, all of the readers in all the newsgroups it is cross-posted
to get to see both the original question and all of the answers given to it.
This is beneficial to you because then we can add additional material to,
add clarification to, as well as add additional examples to an answer you
have received previously... that means you end up with a more complete
solution to your problem. This is a win-win situation for all of us."

Rick
 
Hi Rick,

Roger that. It won't happen again. My apologies for any caused trouble.

Thanks again for your kind and valuable help.

Regards,


RF
 
Back
Top