Manage attributes

Analytica User GuideWorking with Large ModelsManage attributes

Each object, such as a variable, module, or function, is a collection of attributes. Some attributes, notably class, identifier, title, and description, apply to all objects of any class. Others apply only to selected classes. For example, Definition, Inputs, and Outputs apply to Variables and Functions, but not Modules. You can see the Attributes of an object in the Object Window and in the Attribute panel, and edit some of them in Edit mode. This table shows which attributes you can see in these two views for Functions, Modules, and Variables, always, by default, or optionally if you use the Attributes dialog below:

Attribute	Variable	Function	Module
Class	•	•<span style="color:#32CD32">'''✓'''</span>	•
Identifier	•	•	•
Description	•	•	•
Title	•	•	•
Definition	•	•
Units	•	•
Help	+	+	+
Domain	+
Inputs	+	+
Outputs	+	+
Domain	+
Value	+
Probvalue	+
MetaOnly	+
Parameters		+
Recursive		+
Check	+	+
Author			•
Created			•
File Info			•
Last Saved			•
User-created (up to 5)	+	+	+

Key:

plain = editable by user

italic = set by Analytica

• = always displayed

+ = optionally displayed

For descriptions of the attributes, see Glossary.

Attributes dialog

Use the Attributes dialog to control the display of optional attributes in the Object window and Attribute panel and to define new attributes. To open the Attributes dialog, select Attributes from the Object menu.

Class: Use this menu to select variables, modules, or functions, so you can see and select the Attributes for that class.

Attribute list: A list of the attributes optionally visible for the selected class. Attributes with an asterisk (*) are always displayed in the Object window and Attribute panel. Other Attributes with a checkmark are displayed optionally

Display optional attributes

To display an optional attribute in the Object window and Attribute panel, click the attribute once to select it, then again to show a checkmark (√) to indicate it will be shown in these two views.

To hide an optional attribute, click it once to select it, then again to remove the checkmark.

Create new attributes

You can create up to five additional attributes. For example, you could use a Source attribute to include a bibliographic reference or URL for information on which this number or expression of the Variable is based.

To create a new attribute in the Attributes dialog:

Select new Attribute from the attribute list to show the new Attribute Title field and the Create button.
Enter the title for the new attribute in the Title field. The title can contain a maximum of 14 characters; 10 characters are the maximum recommended for visibility with all screen fonts.
Click the Create button to define the new attribute.

A newly created attribute is displayed for modules, variables, and functions. To control whether or not it is displayed for modules, variables, or functions, select the Class popup menu in the Attributes dialog, and turn the checkmark on or off.

Rename an attribute

To rename a created attribute:

Select it in the Attribute list. The Title field and the Rename button appear.
Edit the name of the attribute in the Title field.
Click the Rename button.

Refer to the value of an attribute

You can access the value of an Attribute in a definition using this construct:

Attrib Of x

Returns the value of attribute «attrib» of object «x», where «x» is a variable, function, module, or other object. For most attributes, including Identifier, Title, Description, Units, Definition, and user-defined attributes the result is a text value. For Value and Probvalue, the result is the value of the variable (deterministic or probabilistic, respectively). For Inputs, Outputs, and Contains (an attribute of a module), the result is a vector of variables. See Attrib of Obj().

You cannot refer to an attribute of a variable by naming the variable in the definition of that variable because that would create a circular reference. Instead, refer to it as Self, for example:

Variable Boiling_point

Units: F

Definition: If (Units of Self) = 'C'

THEN 100 ELSE 212

Boiling_point → 212

Library: Special

Example: Units of Time → 'Years'

Tip

Changes to attributes other than Definition do not automatically cause recomputation of the variables whose definitions refer to those attributes. So, if you change Units of Boiling_point to C, the value of Boiling_point does not change until Boiling_point is recomputed for some other reason.