Creating user-defined attributes

You can create a user-defined attribute in the Base data menu or the Attribute selection window (Selecting attributes and subattributes for columns of a list).

Creating a user-defined attribute in the Base data menu

1. From the Base Data menu, choose > User-defined attributes.

The User-defined attributes list opens. If no user-defined attribute is defined, only the column titles are displayed.

2. In the list, on the toolbar, click the Add button .

The User-defined attribute window opens.

Tip: Alternatively, you can also open the User-Defined Attribute window via the following functions: When doing so, you adopt the network object type as the object type of the user-defined attribute.

On the Network object toolbar, from the shortcut menu of the desired network object type, choose Create User-Defined Attribute.
In the Attributes list of the desired network object type, right-click the row header of the desired network object. Then from the shortcut menu, choose User-Defined Attribute.
In the Attributes list of the desired network object type, on the toolbar, click the Create User-Defined Attribute button .

Note: In lists, you can use the Attribute selection icon to show and hide attribute values (Selecting attributes and subattributes for columns of a list).

3. Make the desired changes:

Element	Description
Object type	Object type of user-defined attribute (mandatory field) In addition to the network object types, you can select other object types, such as Network settings (NETPARA). For NETPARA, choose the data source type Formula to enter a formula value that you can use as a user-defined constant. Select TableLookup to access NETPARA.
Short name	Abbreviated name of user-define attribute (mandatory field)
LongName	Full name
Comment	Optional comment

Element	Description
Data type	A user-defined attribute must have a data type. Select the desired entry.
Data types allowed:
Acceleration	Acceleration
Bool	Enables logical statements for a user-defined attribute that can be assigned 0, 1, or no value: Yes: true, 1 No: false, 0 Empty: Empty value, no value
Filename	Filename: Reference to a file, for example for a user-defined attribute, which lists where to find further information.
Duration (integer)	Time [s] without decimal separator
Duration (floating-point number)	Time [s] with decimal separator
Area (km2)	Square kilometers
Area (m2)	Square meters
Integer	Integer without decimal separators
Speed (km/h)	Speed (km/h)
Speed (m/s)	Speed (m/s)
Floating-point number	Floating-point number with decimal separators
Length (km)	Length (km)
Length (m)	Length (m)
Length (mm)	Length (mm)
Text	String
Currency	Currency
Time	Time in format hh:mm:ss (12:23:12) or hh:mm (12:23)

Element	Description
Subattributes	Simulation run: only for the following objects: User-defined attributes of network objects of the data source type Data that have evaluation attributes and can have user-defined data attributes. The values of these attributes can only be changed during the simulation run and are saved to the evaluation database (*.db). User-defined attributes of the data source type Formula The values of the user-defined attribute are recorded for each simulation run. When you show the user-defined attribute in an attributes list, the attribute values are listed per column for each simulation run. Time interval: For user-defined attribute consider time intervals of network object type. The network object type must be assigned time intervals (Defining time intervals for a network object type). When you show the user-defined attribute in an attributes list, the attribute values are listed per column for each time interval.

Element

Description

Subattributes

Simulation run: only for the following objects:
User-defined attributes of network objects of the data source type Data that have evaluation attributes and can have user-defined data attributes. The values of these attributes can only be changed during the simulation run and are saved to the evaluation database (*.db).
User-defined attributes of the data source type Formula

The values of the user-defined attribute are recorded for each simulation run. When you show the user-defined attribute in an attributes list, the attribute values are listed per column for each simulation run.

Time interval: For user-defined attribute consider time intervals of network object type. The network object type must be assigned time intervals (Defining time intervals for a network object type). When you show the user-defined attribute in an attributes list, the attribute values are listed per column for each time interval.

4. Select the desired data source type.

Data: You can set the following attribute values and options. Depending on the data selected, different boxes and options are displayed in the section on the right.

Element	Description
Allow empty value	If the option is selected, no value may be specified for the user-defined attribute. By default, the option is not selected and the default value is NULL.
Default value	Optional entry of a default value
Minimum	If this option is selected, choose the smallest possible value as default.
Maximum	If this option is selected, choose the largest possible value as default.
Decimal places	Number of decimal places for a value with decimal separator

Formula: You can create a formula in the section on the right (Creating formulas). To do so, you also specify the number of decimal places:
Element Description
Decimals
Number of decimal places for a value with decimal separator

Element	Description
Decimals	Number of decimal places for a value with decimal separator

If the attributes selected for the formula are based on dynamic data that can change during a simulation run, the values of the user-defined attribute displayed in a results or attribute list can also change during the simulation run.

Syntax errors are highlighted in red:

Vissim highlights formula syntax errors in red. Below the entry box for the formula, a message is displayed with information on the possible cause of the syntax error.

5. Confirm with OK.

The User-defined attribute window closes. The user-defined attribute is displayed in the User-defined attributes list.

Example of a user-defined attribute

The user-defined attribute ConflGap will calculate the gap in front for the two links of a conflict area, if Link1 has the Status2 and Link2 has Status1.

For this example the following data are selected or entered:

Object type: Links
Short name: ConflGap
Long name: ConflAreaFrontGap
Comment: Front gap of a conflict area of this link, where vehicles need to observe the right of way
Data type: Entry floating point number
Data source type: Formula option

In the Insert TableLookup window:

Object type: Conflict areas
Variable name: ca

In the Formula entry box, change entry TableLookup(CONFLICTAREA ca; ; ) to:

TableLookup(CONFLICTAREA ca; ca[LINK1\NO]=[NO] & ca[STATUS]=2 | ca[LINK2\NO]=[NO] & ca[STATUS]=1;ca[FRONTGAPDEF])

The user-defined attribute ConflGap is then available as an attribute of the network object type Link. In the Links list, you can show ConflGap as a column. You can also show the Front gap value for each link in the list that has conflict areas with the two statuses defined.

Superordinate topic:

Using user-defined attributes