I need help with my code for a degree in IT

CODE 1:

classdef SurfaceUnit
    properties (Access = private)
        Position
        Threat
        Certainty
    end
    methods
        function obj = SurfaceUnit(varargin)
            if nargin == 3
                obj.Position = varargin{1};
                obj.Threat = varargin{2};
                obj.Certainty = varargin{3};
            else
                unit1 = SurfaceUnit([10,20],'FRD',0.9);
            end
        end
        function out = getPosition(obj)
            function setPosition(obj, p)
                function out = getTreat(obj)
                    function setThreat(obj, t)
                        function out = getCertainty(obj)
                            function setCertainty(obj, c)
                            end
                        end
                    end
                end
            end
        end
    end
end

CODE 2:

classdef AttributeFusion
    properties 
        Unit1
        Unit2
        FusedUnit
    end
    methods
        function obj = AttributeFusion(u1,u2)
            obj.Unit1 = u1;
            obj.Unit2 = u2;
            obj.FusedUnit = SurfaceUnit;
        end
        function out = getFusedUnit(obj)
            out = obj.FusedUnit;
        end
    end
end

CODE 3:

clear; clc;
unit1 = SurfaceUnit([10,20],ThreatValues.FRD,0.9);
unit2 = SurfaceUnit([15,25],ThreatValues.ASF,0.8);
fision = AttributeFusion(unit1, unit2);
fusedUnit = fusion.getFusedUnit;
fusedUnit.getPosition
char(fusedUnit.getThreat)

Well the problem is, that I do not know why my program says that obj section is unused and it may require replacing it with ~.

Answer 1

[Walter Roberson]

        function out = getPosition(obj)
            function setPosition(obj, p)
                function out = getTreat(obj)
                    function setThreat(obj, t)
                        function out = getCertainty(obj)
                            function setCertainty(obj, c)
                            end
                        end
                    end
                end
            end
        end

Those are nested function definitions. setPosition is defined inside of getPosition, getTreat is defined inside of setPosition, and so on. None of the implementations use the input obj so MATLAB warns you that input obj is unused.

You are quite unlikely to want nested function definitions at that point.

[Wiktor]

Well you may have a point. Do you have some tips step by step how to avoid this and make the code work correctly?

Ty a lot

[Walter Roberson]

        function out = getPosition(obj)
        end
        function setPosition(obj, p)
        end

and so on.

Then populate the bodies of the functions with appropriate code, such as

        out = obj.Position;