Calls the named function on a field over a set of events. The result is returned in a field named _function for the selected function. This allows having the function name as a dashboard parameter.

asstringfalse_functionName of output field.
fieldstringtrue Field to extract a number from and calculate function over.
functionstringtrue Function to run. [a]

[a] If an argument name is not given, function is the default argument.

Find the average bytes sent in http responses using callFunction() rather than using avg directly.

avg_sent:=callFunction("avg", field=bytes_sent)

Use a query parameter (i.e., ?function) to select the aggregation function for a timeChart(). This is useful for dashboard widgets.

timechart(function=[callFunction(?{function=count}, field=value)])