Managing attributes
Network objects are described by means of attributes. The Basics manual provides detailed information on attributes (Fundamentals: Attributes). Here is a short overview of the types of attributes in Visum:
- Direct attributes
Direct attributes describe an attribute directly. As a rule, they are predefined and can be subdivided into the following types:
- Input attributes: The user enters the values of these attributes.
- Output attributes (or calculated attributes): The values of these attributes are calculated automatically by Visum.
- Indirect attributes
Indirect attributes are direct attributes of other network objects, which bear a network model relation to the currently selected network object.
- User-defined attributes
In addition to the predefined attributes, the user can define any desired attributes, which they can edit or manage like predefined attributes. Formula attributes are a particular form of user-defined attributes. They are not used for direct storage of data, but represent an operand which encompasses other attributes (Fundamentals: Formula attributes).
- Time-varying attributes
Time-varying attributes only affect the procedures Dynamic User Equilibrium and Dynamic Stochastic assignment. Time variations can only be set for specific network objects with a time reference.
Characteristics of attributes
Each attribute has a unique attribute ID in English, as well as a short name and a long name.
Example: The attribute Number has the attribute ID No, the long name Number and the short name No.
The Attributes.xls file contains the complete list of all network object types and their attributes with IDs, short names and long names.
Video: How To Use the Attribute List