User-defined tables
Table definitions and table entries are user-defined network objects in which you can store additional data. Unlike POIs, tables have no geographical reference and no mandatory attributes. They, therefore, provide an easy way to store additional data of various types in a model. Listed below are some cases where data can be used in user-defined tables:
- Additional input data that enters the procedures with lookup functions, e.g. demand rates per zone type
- Indicators of the model, e.g. the modal split from the demand calculation
- Procedure parameters that are obtained via scripts, e.g. in the calculation of an activity-based model (ABM)
- Statistics outputs to be tracked across iterations in models with feedback loops
- User-defined enumeration types that are used in the model, e.g. for classification of the type of development of bicycle facilities on links
- General information about the history of the model
You can create tables via the Table definitions list (Using Visum: Creating a table definition). The list of associated Table entries contains the data. You can fill the tables with entries in different ways (Using Visum: Creating table entries). In the simplest case, you specify the number of rows and columns when creating the table and paste the values via copy & paste, e.g. from MS Excel. The number of columns corresponds to the user-defined attributes of the table entries. You can also use formula attributes as user-defined attributes to keep values in the table up-to-date. Visum provides functions to transfer values from arbitrary lists or marked parts thereof into tables. Likewise, you can use scripts to copy or append list contents to tables. If you integrate such scripts into the procedure sequence, you can, for example, track the values in statistics lists via the iterations within a feedback loop.