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Event expression


Property of the event object that defines what occurs when the event is triggered. Specify a cell array of character vectors.

EventFcns can be any MATLAB® assignment or expression that defines what is executed when the event is triggered. All EventFcn expressions are assignments of the form 'objectname = expression', where objectname is the name of a valid SimBiology® object.

For more information about how SimBiology handles events, see How Events Are Evaluated. For examples of event functions, see Specifying Event Functions.


Applies toObject: event
Data typeCell array of character vectors
Data valuesExpressions for EventFcn (default is an empty character vector '')


If UnitConversion is on and your model has any event, follow the recommendation below.

Non-dimensionalize any parameters used in the event Trigger if they are not already dimensionless. For example, suppose you have a trigger x > 1, where x is the species concentration in mole/liter. Non-dimensionalize x by scaling (dividing) it with a constant such as x/x0 > 1, where x0 is a parameter defined as 1.0 mole/liter. Note that x does not have to have the same unit as the constant x0, but must be dimensionally consistent with it. For example, the unit of x can be picomole/liter instead of mole/liter.


  1. Create a model object, and then add an event object.

    modelObj = sbmlimport('oscillator');
    eventObj = addevent(modelObj, 'time>= 5', 'OpC = 200');
  2. Set the EventFcns property of the event object.

    set(eventObj, 'EventFcns', {'pA = OpA','mA = pol'});
  3. Get the EventFcns property.

    get(eventObj, 'EventFcns')

See Also

Event, Trigger