Command Line Operation

Stella Simulator is started from the command line. Command line options control how it behaves. For example, the following command:

stella_simulator -p 4 -pd 0.25 my_model.stmx

will run the model file my_model.stmx, pausing every 4 time steps to export data, wait 0.25 seconds, and then import data before resuming. This example uses a time delay to resume after the pause, but writing to a handshake file can also be used and is more reliable for synchronizing with another application.

A single model can also be run multiple times in one invocation with complete control of the parameters for each run and at each time step. This allows applications that need results from several runs, for example, evolutionary optimization algorithms, to quickly collect that data using builtin export to Excel or CSV files.

Licensing

Stella Simulator is licensed for servers, or embedded as part of a desktop solution. In each case, the base license allows for up to 20 concurrent executions. This could be 20 connections to a server executing at the same time, or it could be 20 desktop solutions using Stella Simulator running at the same time (each executing only a single simulation at a time). The number of concurrent executions can be increased for an additional cost.

Parameter Control

The full set of options available with Stella Simulator:

• rn N: Run the model N times
• d seconds: Delay seconds between each model run
• h filename: Use file filename for handshakes between model runs (-d becomes a timeout)
• p interval: Pause the model every interval time units (use 0 for DT)
• pi: Pause immediately after initialization (to get initialization values)
• pd seconds: Resume from pause after seconds
• ph filename: Use file filename for handshakes to resume from pause (-pd becomes a timeout)
• i: Import now before each run
• x: Export now after each run
• 0 variable: Force the given model variable to zero before the first run
• 1 variable: Force the given model variable to one before the first run
• q: Execute in quiet mode (only output errors)