Output Filter

Since MARS supports model scenarios that can potentially generate huge amount of data, the logging of those extensive data can slow the performance of a model (e.g. SmartOpenHamburg models with a huge set of involved agents). The modeler can only be interested in a specific subset of agents or for specific agent-states, e.g., is the agent in specfici state or log data only for an agent of specific attribute.

MARS provides outputFilters for agent to reduce the amount of logged data to those of interest. A dynamic predicate can be provided to filter those entities matching the condition. An agent or entity type can have an optional outputFilter which is able to accept a set of AND associated expressions in form of:

Agent configuration in the config.js

{
    "name": "MyAgent",
    "count": 10000,
    "file": "output.csv",
    "outputFilter": [{
        "parameter": "Species",
        "operator": "in",
        "values": ["SpeciesA", "SpeciesC"]
    }]
}

For this example for an Agent class MyAgent the output rows per tick would only be created, if in the tick the agent's property Species has the value SpeciesA or SpeciesC.

You can define multiple filter which will be chained. All individual filters must evaluate to true if the values of the tick should be logged.

If you don't have a specific property you want to watch for, it can be a good option to define a new property to enable/disable the logging of a tick result like this:

Agent property

public bool StoreTickResult { get; set; } = false;

{
    "name": "MyAgent",
    "output": "csv",
    "outputFilter":[{
        "parameter": "StoreTickResult",
        "operator": "in",
        "values": [true]
    }]
}

In side the Tick() method you can now do as follows. This will log all agent properties only when your expression YourContraint is true.

Tick() method with outputFilter

public void Tick()
{
    // at beginning of each tick set 
    // to false to prevent logging
    StoreTickResult = false;

    // your logic...

    // your logic reached a state where you want 
    // to log all agent properties
    if (YourConstraint)
    {
        StoreTickResult = true;
    }
}