Technical data

ManualsBrandsSimplicity ManualsDo-It-Yourself tools4564

141

142

143

144

145

146

147

148

149

150

Chapter 10 Creating Rules, Formulas, and User Functions

Some functions do not take any arguments because they do not require additional information to calculate a

result. For e xample, the PI function returns the mathematical constant pi. Because this function does not require

any information, it does not take any arguments. Nevertheless, you must still follow the function name with

parentheses. For example, the following formula calculates the circumference of a circle using the PI function:

PI( ) * DIAMTER_OF_CIRCLE

The parentheses following PI indicate that the name is a function rather than a data cube reference.

Many function

s have one or more optional arguments. If y ou leave out an optional argument, the analytic

calculation e

ngine supplies a default value for the argument. For example, the CHANGE function calculates

the change bet

ween members of a dimension and takes these arguments in order:

1. The dimension for which you want to calculate the change.

2. The information for which you want to calculate the change.

3. How many members back to look.

Note. The third argument is optional; if you do not include it, the analytic calculation engine assumes

you want to calculate the change from only the previous member.

For example, s

uppose you want to calculate the monthly c hange in sales. You can use the C HANGE function

and leave out

the third argument, as shown in the following formula:

CHANGE(MONTHS, SALES)

For each month

, the analytic calculation engine calculates the change in sales from the previous month.

Now suppose you want to calculate the yearly change in sales. Yo u can use the CHANGE function and supply

12 as the third argument, as shown in the following formula:

CHANGE(MONTH

S, SALES, 12)

For each month, the analytic calculation engine calculates the change in sales from 12 previous months. To

summarize:

• You must always place parentheses after a function name.

• If a function contains arguments, place the arguments inside the parentheses.

• If a function contains more than one argument, separate the arguments with commas.

• You can leave out an optional argument if the default value for the argument is satisfactory.

See C

hapter 11

, “Using Built-in Functions in Analytic Models,” CHANGE, page 144.

Conditions and Conditional Formulas

A condition is an expression that evaluates as true or false. A conditional formula returns different values for

different conditions. The most simple conditional formula returns one value if a specified condition is true, and

a different value if the condition is false. A complex conditional formula may return many different values

based on many different conditions. These are types of conditions and conditional formulas:

• Comparison o

perators.

• Truth functi

ons.

• Compound con

ditions.

See “Comparison Operators”, “Truth Functions”, “Compound Conditions.”