java - Is it possible to modify experiment parameter values after a model is run?

Question

I'm following the Integrating AnyLogic Models with External Java Applications module and while I am able to change parameters before I run the exported java application, it seems the values become immutable once the model runs. Is there a way to dynamically modify parameter values at runtime?

Below is a snippet of my Java code:

    final Simulation s = new Simulation();
    IExperimentHost host = new ExperimentHost(s);
    s.parameter1 = 50;
    s.setup(host);
    host.launch();
    s.runTheModel();
    s.parameter1 = 100;

The result is that parameter1 never changes from 50 to 100. Is there a way to circumvent this?

Answer 1

Try set_parameter. The help menu talks about this a little bit.

Edit: Your original question was not directly linked to running as an external java application, but I think this could really simplify things. When you export your java application, look at the .bat file. You will see what the command line would look like to run the model. What we do when we are running from an external application is just have the external application call this command line, as opposed to what AnyLogic discusses in the help menu. A significant advantage of this is that you can easily mimic in the development environment what is going on in the exported model.

Ask your self why you are changing these parameters at runtime. Is it because of a read statement and you just don't have the data prior to the model run? If so, think about the order you instantiate your objects and don't start them until after you have the variables set that you want to use. This can be done by passing in parameters to main, setting database values, or having the main agent do various read statements.

Is it that you just want items to change over time? If so, consider variables, instead of parameters. Consider other objects that may allow you to more easily change flow. For example, does a valve before a pipeline or other sequence give you the level of control that you want?

At this point, would probably need more detailed information about what you are trying to accomplish / the system you are modeling, in order to provide any more specific advice.