Defining Dimensional Constraints Parameters
You can control Dimensional Constraint geometry with mathematical equations and expressions.
Parametric equations include:
 The names of the Dimensional Constraints
 Expressions, in which you can use:
 Values
 Userdefined variables, and variables that represent existing Dimensional Constraints
 Mathematical operators, functions, and constants
Expressions for Dimensional Constraints
When you create a Dimensional Constraint, an equation defines the dimension of an entity or between points on entities in the form name=value, for example d1=12.34.
You can replace the value by an expression: name=expression.
 Within the expression, you can use values, variables, mathematical operators, and mathematical functions and constants.
 The result of an expression is a value.
A variable can be one of the following:
 Userdefined, for example length1=12.5
 An existing Dimensional Constraint name, for example d2=rad1
Use the Parameters Manager to define and edit expressions and variables.
You can also edit expressions inplace.
Dimensional Constraints Equation Examples
Example 
Description 
d1=rad1 
Sets the variable d1 to the value of the variable rad1. 
d2=rad2*2 
Multiplies the variable rad2 by 2 and sets the variable d2 as the result. 
length1=cos(ang1) 
Sets the userdefined variable length1 to the value of the cosine of angle ang1. 
dist1=(length1 + d1) / 2 
Sets the userdefined variable dist1 to the sum of the userdefined variable length1 and the variable d1 divided by 2. 
Constraint Names
Dimensional Constraints (both Dynamic and Annotation constraints) are identified by name, as well as userdefined variables used in expressions and formulas.
The Parameters Manager lists all Dimensional Constraints variables with their names, expressions, and values.
The naming conventions are:
Meaning 
Default Name 
Constraints 
Distance 
d1, d2, ..., dn 
Aligned, Horizontal, Vertical 
Diameter 
dia1, dia2, ..., dian 
Diameter 
Radius 
rad1, rad2, ..., radn 
Radial 
Angle 
ang1, ang2, ..., angn 
Angular 
Userdefined 
user1, user2, ..., usern 
Used in expressions 
To rename constraint variable names:
 Specify a Dimensional Constraint.
 In the Properties palette, under Constraint, edit the Name.
 or 
 Specify a Dimensional Constraint.
 In the Parameter Manager palette, under Dimensional Constraints, edit the Name.
 or 
 Doubleclick a Dimensional Constraint.
 Edit the variable name in place.
Note: Constraint variable names must be unique.
Parametric Equations
Use operators and functions to define formulas and equations.
The evaluation of expressions follows standard mathematical rules.
Operators
You can use the following operators in expressions and formulas:
Operator

Description 
+ 
Addition 
 
Subtraction (or unary negation) 
* 
Multiplication 
/ 
Division 
^ 
Exponentiation 
% 
Floating point modulo 
. 
Decimal separator 
(expr) 
Parentheses to define expressions 
Functions
You can use the following functions in expressions and formulas:
Function 
Syntax 
Cosine 
cos (expr) 
Sine 
sin (expr) 
Tangent 
tan (expr) 
Arc cosine 
acos (expr) 
Arc sine 
asin (expr) 
Arc tangent 
atan (expr) 
Hyperbolic cosine 
cosh (expr) 
Hyperbolic sine 
sinh (expr) 
Hyperbolic tangent 
tanh (expr) 
Arc hyperbolic cosine 
acosh (expr) 
Arc hyperbolic sine 
asinh (expr) 
Arc hyperbolic tangent 
atanh (expr) 
Square root 
sqrt (expr) 
Signum function (1,0,1) 
sign (expr) 
Absolute value 
abs (expr) 
Truncate decimal 
trunc (expr) 
Round to nearest integer 
round (expr) 
Round down 
floor (expr) 
Round up 
ceil (expr) 
Largest element in array 
max (expr1;expr2) * 
Smallest element in array 
min (expr1;expr2) * 
Degrees to radians 
d2r (expr) 
Radians to degrees 
r2d (expr) 
Logarithm, base e 
ln (expr) 
Logarithm, base 10 
log (expr) 
Exponent, base e 
exp (expr) 
Exponent, base 10 
exp10 (expr) 
Power function 
pow (expr1;expr2) * 
Random decimal, 01 
random 
Constant pi 
pi 
Constant e 
e 
*) Uses the list separator (semicolon or comma) as defined in the OS format settings.
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Expression Evaluation
According to standard mathematical rules expressions are evaluated using the following precedence:
 Expressions within parentheses (innermost parentheses first)
 Standard operations order:
 Exponents
 Multiplication and division
 Addition and subtraction
 Operators of equal precedence from left to right.