Calc Guide

Understanding the structure of functions
All functions have a similar structure. If you use the right tool for
entering a function, you can escape learning this structure, but it is
still worth knowing for troubleshooting.
To give a typical example, the structure of a function to find cells that
match entered search criteria is:
= DCOUNT (Database;Database field;Search_criteria)
Since a function cannot exist on its own, it must always be part of a
formula. Consequently, even if the function represents the entire
formula, there must be an = sign at the start of the formula.
Regardless of where in the formula a function is, the function will start
with its name, such as DCOUNT in the example above. After the name
of the function comes its arguments. All arguments are required,
unless specifically listed as optional.
Arguments are added within the parentheses and are separated by
semicolons, with no space between the arguments and the semicolons.
Note
OOo uses the semicolon as an argument list separator, unlike
Excel which uses a comma. This is a common mistake made by
users accustomed to entering Excel formulas.
Many arguments are a number. A Calc function can take up to thirty
numbers as an argument. That may not sound like much at first.
However, when you realize that the number can be not only a number
or a single cell, but also an array or range of cells that contain several
or even hundreds of cells, then the apparent limitation vanishes.
Depending on the nature of the function, arguments may be entered as
follows:
"text data" The quotes indicate text or string data is being entered.
9 The number nine is being entered as a number.
"9" The number nine is being entered as text
A1 The address for whatever is in Cell A1 is being entered
Nested functions
Functions can also be used as arguments within other functions. These
are called nested functions.
=SUM(2;PRODUCT(5;7))
198 OpenOffice.org 3.x Calc Guide