Updating attributes during simulation based on events

You can define attribute changes that are executed at specified times during a simulation run. To do this, select the desired attribute, which Vissim will set to a new value for all objects of the specified object type, calculated by the specified formula.

You can only use object types that have at least one attribute that can be changed during the simulation.

If a script has been defined for the same time step, Vissim will first make the attribute change.

1. On the Actions menu, click > Attribute modifications.

The Attribute modifications list opens.

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

The Attribute modification window opens.

3. Make the desired changes:

Element	Description
No.	Unique Number of the attribute modification
From time	TimeFrom: Time interval in simulation seconds from which the attribute change is active. Default 0.00 s
To time	TimeTo: Time interval in simulation seconds until which the attribute change is active
Period	Period: Selecting length of simulation time intervals (number of time steps) carried out for attribute change
Name	Name: Name of the attribute change
Execution type	RunType: Either select Manually for entering the value or the desired time at which the value shall be recorded: Before simulation start After simulation start At time step start At time step end Before simulation end After simulation end
Object type	ObjTypName: From the drop-down list, select the network object type that contains the attribute whose value is to be changed during the simulation.
Target attribute	TargetAttrName : Opens the window <Network object type>: Select attribute. All attributes of the network object type are displayed. Invalid values are crossed out. 1. Click the desired network object. You can filter the entries (Setting a filter for selection of subattributes displayed). 2. Confirm with OK.
Object filter	Optional formula that can be used to restrict the set of objects for which the attribute change is to be performed. The formula is re-evaluated with each attribute change. If the new value from the formula matches the value of the target attribute, the value is not reassigned.
Value assignment	Distribution (Distr): Enables the Distribution box, disables the Formula box. Select the desired distribution of the Free type. The free distribution value is rounded when it sets a reference to object. It is then interpreted as a key for the object that must be set with the target attribute. Formula: Enables the Formula box, disables the Distribution box. Create the formula using the buttons and/or the keyboard (Creating formulas). If the formula is numeric but the target attribute is a string, Vissim will convert the numeric to string.

3. Confirm with OK.

In the Attribute modification list, a new row is inserted. In the Attribute computation column, the formula created in the input field is displayed.

Superordinate topic:

Running a simulation