So I have a certain function f(x), where x is a positive integer value.

I would like another function g(y) which is the sum of all values of f(x), with
x ranging from 0..y

This is trivial using Sigma notation.  Unfortunately, this is not available in
any spreadsheet I know of (I use MS Office at work, and OpenOffice.org at
home).

I'd rather not write a macro for this, as that seems to me as useful as writing
a macro to do addition (in fact, it *is* addition).  Just the thought that I'd
have to script something so basic and intuitive is abhorant to me.  Not to
mention that every time I opened the spreadsheet, I'd have to deal with those
annoying security warnings about dangerous macros.

I could populate an entire column on a separate sheet with the values I need,
but then every time the calculation is done all the cells in that column would
have to be calculated.  The programmer in me hates all that wasted calculation,
and wants to "optimize" it away by only calculating what I actually need
(although I might not call it optimization, since really I'm just getting it to
do what I want it to do in the first place).

I've tried googling, but came up with nothing but introductions on how to use
the SUM() function, which is not what I want.  If Google is my friend, then it
isn't one with benefits.

Does anyone here have an idea of how to calculate a sum this way?

....Chambers
www.pacificwebguy.com

Post a reply to this message