Operators

Analytica User GuideUsing ExpressionsOperators

An infix operator is a symbol, such as a plus sign (1+2) or product (10*2), that operates on the values before and after it. A prefix operator, such as unary minus (-100) operates only on the value after it. Analytica includes these fairly standard opera tors, including arithmetic, comparison, and logical operators:

Arithmetic operators

The arithmetic operators apply to numbers and produce numbers:

Operator	Meaning	Examples
x + y	plus	[math]\displaystyle{ 3 + 2 → 5 }[/math]
x - y	binary minus	[math]\displaystyle{ 3 - 2 → 1 }[/math]
-x	unary minus	[math]\displaystyle{ -2 → -2 }[/math]
x*y	product	[math]\displaystyle{ 3*2 → 6 }[/math]
x/3 or x÷y	division	[math]\displaystyle{ 3/2 (= \frac{3}{2}) → 1.5 }[/math]
x^y	to the power of	[math]\displaystyle{ 3^2 = 3^2 → 9 }[/math] [math]\displaystyle{ 4^.5 = 4^{\frac{1}{2}} → 2 }[/math]

Comparison operators

Comparison operators apply to numbers and text values and produce Boolean values.

Operator	Meaning	Examples	→ (1 = true, 0 = false)
<	less than	2 < 2 'A' < 'B'	→ 0 → 1
<=	less than or equal to	2 <= 2 'ab' <= 'ab'	→ 1 → 1
=	equal to	100 = 101 'AB' = 'ab'	→ 0 → 0
>=	greater than or equal to	100 >= 1 'ab'> = 'cd'	→ 1 → 0
>	greater than	1 > 2 'A' > 'a'	→ 0 → 1
<>	not equal to	1 <> 2 'A' <> 'B'	→ 1 → 1

Alphabetic ordering of text values

You can apply the comparison operators, <. >, >=, <=, or sorting functions, SortIndex(d, i), Sort(d, i) and Rank(), to text values. They generally use alphabetical order as in a dictionary, so:

'Analytica' < 'Excel' → 1 (True)

These operators and functions are normally case sensitive, so uppercase letters precede lowercase letters:

'Analytica' > 'excel' → 0 (False)

If you want alphabetic ordering to ignore case, use TextUpperCase() or TextLowerCase() to convert all letters to the same case.

TextUpperCase('Analytica') < TextUpperCase('excel') → 1 (True)

In functions, SortIndex(d, i), Sort(d, i) and Rank(), you can set their optional parameter «caseInsensitive» to True if you want them to ignore case.

Usually, digits precede letters:

'9' < 'A' → 1 (True)

The collation order of characters is region-specific collation, according to your language and country. It is determined by the TextLocale system variable. If you want to see or change the collation order, bring up the Object Window for TextLocale by selecting it from the Definition → System Variables menu, with nothing selected and while in edit mode.

In general, the ordering of text may be different from the ordering implied by the numeric ASCII codes of the characters. For example, 'de' < 'dé' < 'df', whereas the ASCII code for 'é' comes after the ASCII code for 'f'. If you want text comparisons to use simple ASCII ordering, you can set TextLocale to be ANSI.

When two text values do not contain identical character sequences, they are considered to be unequal, even if they represent the exact same text. This can happen in Unicode with combining characters. For example, an accented 'é' can be either Chr(233) or Chr(769)&'e', where the Unicode Chr(769) is the combining acute accent, which modifies the character that follows. Although these alternate representations of 'é' are non-equal, they will have the same inequality comparisons with all other text, as if they are as closely adjacent in the sort order as is possible.

Logical operators

Logical operators apply to Boolean values and produce Boolean values.

Operator	Meaning	Examples
b1 AND b2	true if both b1 and b2 are true, otherwise false	5 > 0 AND 5 > 10	→ False
b1 OR b2	true if b1 or b2 or both are true, otherwise false	5 > 0 OR 5 > 10	→ True
NOT b	true if b is false, otherwise false	NOT (5 > 0)	→ False

Scoping operator (::)

It is possible that a model created in a previous release might contain a variable or function with the same identifier as a new built-in variable or function. In this situation, an identifier name appearing in an expression might be ambiguous.

Prepending :: to the name of a built-in function causes the reference to always refer to the built-in function. Otherwise, the identifier refers to the user’s variable or function. With this convention, existing models are not changed by the introduction of new built-in functions.

Example: Suppose a model from an older release of Analytica contains the user-defined function Irr(Values, I). Then:

Irr(Payments, Time) User’s Irr function

Irr(Payments, Time) The built-in function

Operator binding precedence

Analytica uses a standard precedence hierarchy resolves potential ambiguity when evaluating operators in expressions with multiple operators. For example,

1/2*3 - 3^2 + 4

is interpreted as:

(((1/2)*3) - (3^2)) + 4

It binds arithmetic operators before comparison operators and comparison operators before logical operators, and all of these before IF...THEN...ELSE ... and other language constructs, so: IF d + e < f^g OR a AND b > c THEN x ELSE y + z is interpreted as:

IF (((d + e) < (f^g)) OR (a AND (b > c))) THEN x ELSE (y + z)

The binding precedence for operators, from most tightly bound to least tightly bound, is:

1. parentheses ()
2. function calls
3. Not
4. @I, \A, \[I]A, #R.
5. A.I
6. A[I = x]
7. Attrib of Obj
8. ^
9. - (unary, negative)
10. *, /
11. +, - (binary, minus)
12. m..n
13. <, >, <=, >=, =, <>
14. And
15. Or
16. & (text concatenation)
17. :=
18. If-Then-Else, Ifonly-Then-Else, Ifall-Then-Else
19. Sequence of statements separated by semicolons, sequence of elements or parameters separated by commas

Within each level of this hierarchy, the operators bind from left to right (left associative). For example,

1/2*3

is interpreted as:

(1/2)*3

not as

1/(2*3)

See Also

• Comparison Operators

Text valuesOperatorsIF a THEN b ELSE c