Метка: parameters in Inventor

How to use algebraic equations and functions in the Inventor program parameters

The Inventor program has a very useful function that allows you to set various parameters with equations, in which you can use algebraic and trigonometric functions.

Equations can be simple, as well as with multiple algebraic operators, prefixes, and functions. Below is an example of a simple equation.

2 ul *(6+3)

The following complex equations use internal parameters such as pi.

(PI rad/5 ul +(25 deg *PI rad)/180 deg))

The following is a list of algebraic operators supported by Autodesk Inventor.

Operator

Value

+

summation

—

subtraction

%

остаток от деления числа с плавающей точкой

*

remainder of the floating-point number division

/

division

^

exponentiation

(

delimiter in an expression

)

delimiter in an expression

;

separator in functions with multiple arguments

The following table lists the unit prefixes supported by Autodesk Inventor.

Prefix

Symbol

Value

exa

E

1.0e18

peta

P

1.0e15

tera

T

1.0e12

giga

G

1.0e9

mega

M

1.0e6

kilo

k

1.0e3

hecto

h

1.0e2

deca

da

1.0e1

deci

d

1.0e-1

centi

c

1.0e-2

milli

m

1.0e-3

micro

micro

1.0-6

nano

n

1.0-9

Pi co

p

1.0e-12

femto

f

1.0-15

atto

a

1.0e-18

When you use unit prefixes in an equation, enter the prefix symbol. Do not enter the prefix itself. For example, an equation that includes the unit «nanometer» might look like this equation: 3.5 ul * 2.6 nm.

When you add the unit prefix for name to the meter unit, your equation is calculated based on the length of 2.6 nanometers.

Supported Functions

The following table lists the supported functions.

Syntax

Returns Unit Type

Expected Unit Type

cos(expr)

unitless

angle

sin(expr)

unitless

angle

tan(expr)

unitless

angle

acos(expr)

angle

unitless

asin(expr)

angle

unitless

atan(expr)

angle

unitless

cosh(expr)

unitless

angle

tanh(expr)

unitless

angle

acosh(expr)

angle

unitless

asinh(expr)

angle

unitless

sqrt(expr)

unit^1/2

any

sign(expr)

unitless

any (Return 0 if negative, 1 if positive.)

exp(expr)

unitless

any (Return exponential power of expression: for example, return 2 for 100, 3 for 1000, and so on.)

floor(expr)

unitless

unitless (Next lowest whole number.)

ceil(expr)

unitless

unitless (Next highest whole number.)

round(expr)

unitless

unitless (Closest whole number.)

abs(expr)

any

any

max(expr1;expr2)

any

any

min(expr1;expr2)

any

any

In(expr)

unitless

unitless

log(expr)

unitless

unitless

pow(expr1;expr2)

unit^expr2

any and unitless, respectively

random(expr)

unitless

unitless

isolate(expr;unit;unit)

any

any
Function names are case sensitive. Enter them exactly as they appear in the previous table.
 

The following table lists the reserved system parameters supported by Autodesk Inventor

Parameter

Value

PI

3.14159265358979323846264338328

E

2.71828182845904523536

The unit type that you use with an equation depends on the type of data that you are evaluating. For example, to evaluate a linear or angular value, you typically use a unit type of millimeters, inches, or degrees (mm, in, or deg).

Some equations must return a unitless value, for example, an equation to solve the number of occurrences in a pattern. You designate a unitless value with the characters ul. For example, 5 ul means that the equation has been evaluated and returned the number 5, as in the number of occurrences in a pattern.

Keep units consistent within equations containing parameters that represent different unit types. You can do this using the Isolate function. For example, to calculate the number of occurrences for a pattern that is based on one occurrence for each unit of a parameter named Width, your linear equation would be:

isolate(Width;mm;ul)

The number of Occurrences value in a dialog box requires a unitless (ul) result, but you are referencing the unit width, which is a linear value. Convert the Width parameter to a unitless value.