# Implement parameters “getter” methods¶

As described in an earlier section, external parameters of the processor, i.e., those that can be modified by the user, are implemented as Dependent properties of your processor class. For your implementation to be valid, a “getter” method needs to be implemented for each of these parameters. If not, Matlab will generate an error when trying to access that parameter value. If a property is set as Dependent, then its getter method will be called whenever the program tries to access that property. In general, this can be useful for a property that depends on others and that need to be recomputed whenever accessed. In the present case, we will set the getter method to read the corresponding parameter value in the parameter object associated with your processor. If the value of the parameter has changed throughout the processing (e.g., in response to feedback), then we are sure to always get the updated value.

“Getter” methods for parameters are implemented without any method attribute and always follow the same structure. Hence they can easily be copy/pasted and adjusted:

methods

function value = get.parName(pObj)
value = pObj.parameters.map('xx_parNameTag')
end

% ... implement one get. method for each parameter

end


In the above example, parName is the name of the parameter as a dependent property of your processor class, and xx_parNameTag is the name of the parameter defined in the static .getParameterInfo method. pObj represents an instance of your processor class, it does not need to be changed across methods.