MATLAB: Listen for Changes to Property Values

MATLABoop

I would like to update the RMS object property always when the signal object property has change:
classdef track < handle    
    properties
  rms = 0;
    end
    properties (SetObservable)
        signal = [1 2 3 4 5 6 7 8 9 10];
    end
    methods
        function obj = update_rms(obj)
            obj.rms = rms(obj.signal);
        end
    end
end
I don't understand very well the Matlab link: https://www.mathworks.com/help/matlab/matlab_oop/listening-for-changes-to-property-values.html#brkimdj-1
EXAMPLE:
% Init object:
myObj = track();
% Signal property manual update:
myObj.signal = [1 1 1 1];
% After this, I would like that myObj update automatically the RMS property calling the update_rms method.
Could you help me?

Best Answer

If I understood correctly, wouldn't the following be the simplest way to implement what you want:
   classdef (ConstructOnLoad) track < handle
        properties (SetAccess = private)  %I assume that rms cannot be set by the user
            rms;
        end
        properties
            signal = 1:10;
        end
        methods
            function this = track()
                this.UpdateRms();
            end
            function set.signal(this, value)
                this.signal = value;
                this.UpdateRms();
            end
        end
        methods (Access = private)
            function UpdateRms(this)
                this.rms = rms(this.signal);
            end
        end
    end
No need for dependent properties or listener. Just recalculate rms whenever signal is updated.
The ConstructOnLoad is there to ensure that rms is recalculated when a class object is reloaded from disk. It's not strictly necessary since rms and signal should never be out of sync even when read from disk.
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