Experiments

In addition to running single simulation runs, HASH enables simultaneous simulation runs with different parameters. In HASH, experiments are defined in the experiments.json file. Currently supported are:

• linspace - vary a single parameter within a range

• arange - vary a parameter based on an increment

• values - manually enter values for a specific parameter

• monte-carlo - generate random numbers according to a distribution

• group - group together multiple experiment types into a single experiment

For example, this values experiment will run seven experiments, setting a different value of [0..6] in the radius field in each one.

experiments.json
{
    "Sweep values": {
        "type": "values",
        "field": "radius",
        "values": [0,1,2,3,4,5,6],
        "steps": 100    
    }
}

To run an experiment, click the "Experiment Runner" button in the runner controls, denoted with a beaker icon. The option "Sweep Values" will be available in the selector.

Running this experiment will generate 7 new simulations, each with a slightly different globals.json. If we run the simulation, we can see exactly which parameters get changed in the sidebar:

To access the changed varied parameter from within the simulation, we simply access that parameter in globals:

const behavior = (state, context) => {
  const { radius } = context.globals();
};

Now, any behaviors that rely on the "radius" parameter from globals will use the corresponding value.

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