Autodesk 00128-051462-9310 - AUTOCAD 2008 COMM UPG FRM 2005 DVD, User Manual

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Understanding Formulas
Formulas are user-defined equations for calculating the value of a property. You can use a formula to add data about
a selected group of objects or object styles to a schedule table after you define the formula property set definition. and
then add the formula property definition to a property set definition. For more information about property sets and
property set definitions, see “
Property Sets and Property Set Definitions ” on page 2024.
The worksheet you use to specify the formula also lets you evaluate sample results. Formulas can contain variables,
operators, and functions allowed in VBScript. For more detailed information about VBScript, go to
http://msdn.microsoft.com and search for “VBScript Language Reference.” Additionally, in the Formula Property Definition
worksheet, links to online Help are available from the Insert VBScript code and Formula context menus for VBScript
items used in the formula.
Adding a Formula Property Definition to a Property Set Definition
Use this procedure to add a formula property definition to a property set definition. Formula property values can be
computed based on the values of other property data. (For more information about how a formula is evaluated, see
“
Formula Evaluation ” on page 2075.) For example, width and height are automatic door properties, which you can use
to compute the perimeter of the door. Defining (2 * [Width]) + (2 * [Height]) as a formula for a 36" x 84" door results
in a value of 240. A formula property definition is a type of automatic property, because the value it displays is determined
automatically, based on its definition, and cannot be edited directly.
NOTE There is no conversion made between units for a formula result.
Formulas can be simple mathematical expressions, such as 2+2. They can also contain variables, operators, and functions
allowed in VBScript, as shown in the examples below.
Statements
Set Statement Property Get Statement For Each...Next Statement Call Statement
Sub Statement Property Let Statement For...Next Statement Class Statement
While...Wend Statement Property Set Statement Function Statement Const Statement
Set Statement Public Statement If...Then...Else Statement Dim Statement
With Statement Randomize Statement On Error Statement Do...Loop Statement
ReDim Statement Option Explicit Statement Erase Statement
Select Case Statement Private Statement Execute Statement
Functions
ScriptEngineMinorVersion LBound Escape Abs
Second LCase Eval Array
SetLocale Left Exp Asc
Sgn Len Filter Atn
Sin LoadPicture FormatCurrency CBool
Space Log FormatDateTime CByte
Split LTrim FormatNumber CCur
Sqr Maths FormatPercent CDate
StrComp Mid GetLocale CDbl
String Minute GetObject Chr
Tan Month GetRef CInt
Time MonthName Hex CLng
Timer MsgBox Hour Conversions
TimeSerial Now InputBox Cos
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