Autodesk 24000-000000-9860 - Revit Architecture - PC, User Manual

Page: 405 / 1646

Adding a Formula to a Parameter
1 In the Family Editor, lay out reference planes.
2 Add dimensions, as required.
3 Label the dimensions. See Labeling Dimensions on page 359.
4 Add the geometry, and lock the geometry to the reference planes.
5 On the Design Bar, click Family Types.
6 In the Family Types dialog, in the Formula column next to the appropriate parameter, type the
formula for the parameter. For more information about entering formulas, see
Valid Formula
Syntax and Abbreviations on page 367.
Valid Formula Syntax and Abbreviations
Formulas support the following arithmetic operations: addition, subtraction, multiplication, division,
exponentiation, logarithms, and square roots. Formulas also support the following trigonometric functions:
sine, cosine, tangent, arcsine, arccosine, and arctangent.
The valid formula abbreviations for arithmetic operations and trigonometric functions are
■
Addition— +
■ Subtraction— -
■ Multiplication—*
■ Division—/
■
Exponentiation—^: x^y, x raised to the power of y
■ Logarithm—log
■ Square root—sqrt: sqrt(16)
■ Sine—sin
■ Cosine—cos
■ Tangent—tan
■ Arcsine—asin
■ Arccosine—acos
■ Arctangent—atan
■ e raised to an x power—exp
■ Absolute Value—abs
You can enter integers, decimals, and fractional values in formulas, using normal mathematical syntax, as
shown in the examples below:
■ Length = Width + sqrt(Height*Width)
■ Length = Wall 1 (1 Wall 2 (15000mm)
■ Area = Length (500mm) * Width (300mm)
■ Volume = Length (500mm) * Width (300mm) * Height (800 mm)
Using Formulas for Numerical Parameters | 367