Maptitude Help / Formulas, Conditions, and Functions / How Maptitude Calculates a Formula

How Maptitude Calculates a Formula

Maptitude performs the operations in a formula according to a set order. The order is determined by the precedence number of each operation. The lower the precedence number, the earlier in the process Maptitude performs that operation. Maptitude performs operations with the same precedence number sequentially from left to right in the formula. The following table shows the precedence number for all Maptitude operations.

Precedence Number	Operation	Operators
1	Parentheses	( )
2	Identification of value as negative or positive	- +
2	Multiplication and division	* /
3	Addition and subtraction	+ -
3	String concatenation	+
4	Equals relation	= eq
4	Not-equal-to relation	<> ne
4	Less-than relation	< lt
4	Greater-than relation	> gt
4	Less-than-or-equal-to relation	<= le
4	Greater-than-or-equal-to relation	>= ge
4	Range relation	between...and...
5	Logical NOT	not !
6	Logical AND	and &
7	Logical OR	or \|
8	Conditional expression	if...then...else...

You can use parentheses to change the order in which operations are performed. Everything inside the parentheses is evaluated before evaluating anything outside the parentheses. Here are some examples:

Example Description

Age16 + Age17 / Population This looks simple, but because the division operator (/) gets precedence over the addition operator (+) this formula first calculates the number of persons aged 17 divided by the total population, then adds the number of persons aged 16. This is probably not very useful.

(Age16 + Age17) / Population First calculates the sum of persons aged 16 and 17 then divides that sum by the total population. The parentheses around the age fields force the sum to be calculated first. This gives the proportion of 16- and 17-year-olds to the total population, which is very different from the first example, even though they look similar.