Registers a column in the data to be collected each period.
key — str, required
A unique name to refer to the column.
func — func(Model), required
A reporter function (such as one generated by
data.agentReporter()) that takes one argument, the
modelobject, and returns a value to be entered in that period's row of the column.
smooth — int, optional
Replaces the series with a decaying average for the purposes of graphing. Higher values smooth the data more strongly. The original data is recorded in a new column with the same name but postfixed with
Default value: None