why does this formula have to be entered as an array formula?

[Guest]

Here's the formula:
=SUM((C31:C46)*(E31:E46))-SUM((C47:C51)*(E47:E51)/2)+SUM((C54:C59)*(E54:E59))+SUM((C67:C71)*(E67:E71))

My guess is that these are matrices being multiplied together and matrix
algebra is different than straight multiplication. So, Excel requires
CTRL+SHIFT+ENTER to tell its calculation enginge to do matrix
multiplication....

Am I correct here?

Also: it seems to me that the same calculation can be done with SUMPRODUCT.

Dave

 

[Niek Otten]

Check this site for SUMPRODUCT as an alternative to array functions:

http://xldynamic.com/source/xld.SUMPRODUCT.html
--
Kind regards,

Niek Otten
Microsoft MVP - Excel

| Here's the formula:
| =SUM((C31:C46)*(E31:E46))-SUM((C47:C51)*(E47:E51)/2)+SUM((C54:C59)*(E54:E59))+SUM((C67:C71)*(E67:E71))
|
| My guess is that these are matrices being multiplied together and matrix
| algebra is different than straight multiplication. So, Excel requires
| CTRL+SHIFT+ENTER to tell its calculation enginge to do matrix
| multiplication....
|
| Am I correct here?
|
| Also: it seems to me that the same calculation can be done with SUMPRODUCT.
|
| Dave
|
| --
| Brevity is the soul of wit.

 

[Dana DeLouis]

=SUM((C31:C46)*(E31:E46))-SUM(...)/2+Sum(...) + Sum(...)

If you wish, you could use just one "Sum" function as in this Array formula.

=SUM(C31:C46*E31:E46,-(C47:C51*E47:E51)/2,C54:C59*E54:E59,C67:C71*E67:E71)

 

[Guest]

Thanks