Excel calculation engine

[CHEE HAU]

Does anybody know how Excel calculates certain functions
such as SUMPRODUCT and SUMIF in memory?

So, for SUMPRODUCT, does Excel multiply the nth element in
1st array against the corresponding nth element in 2nd
array to create a temporary value which is then added to
the calculated value of n-1 element in 1st array
multiplied by the corresponding n-1 element in 2nd array?

Or does Excel create a third array in memory and populate
each element with the corresponding calculated value of
1st array multiplied by 2nd array before summing up?

 

[CHEE HAU]

I considered that too but for built-in funcrions, the
formula auditing calculates straight through to the answer.

You are right about the usefulness of the functionality
when determining if the array formulas are working as you
envisage.

Thanks
CHEE

 

[Harlan Grove]

Does anybody know how Excel calculates certain functions
such as SUMPRODUCT and SUMIF in memory?

So, for SUMPRODUCT, does Excel multiply the nth element in
1st array against the corresponding nth element in 2nd
array to create a temporary value which is then added to
the calculated value of n-1 element in 1st array
multiplied by the corresponding n-1 element in 2nd array?

Or does Excel create a third array in memory and populate
each element with the corresponding calculated value of
1st array multiplied by 2nd array before summing up?

Since these are effectively 'black boxes', why does it matter?

 

[CHEE HAU]

Thanks for your helpful comments. So you don't know the
answer then.