Formula Parameter 

Definition:  The Formula parameter allows users to create spreadsheetlike formulae.
Within the formula field you can call any mathematical functions supported by AgentSheets and Ristretto. This allows arbitrarily complex relationships to be set up using Mathematical Operators that define relationships between attribute or simulation property values within and between interacting agents. An example of a Formula parameter is shown below in the context of the Set action, where the pollution attribute is being set to the average of the pollution of the agents around it: pollution = (pollution[left] + pollution[right] + pollution[up] + pollution[down]) / 4 