A question about Matlab class

My question is demonstrated as in the attached code. The problem is that the code responds are not as I expected. In selfTest() function, I set the variable b = a, where a is a local variable of the function MyClass.selfTest(). But actually b is set to be "this" obj (the object a in the function TestMyClass()). What is wrong here?

In all the functions I used an input argument "obj". Without this "obj" as the argument, an error message "Too many input arguments" will be generated. What is wrong again?

Any help would be appreciated!

============================================================

function TestMyClass()

a = MyClass(magic(3)', [1 0 0]); %% this line runs fine

a.mat() %% 'Too many input arguments.' error

a.vec %% 'Too many input arguments.' error

a.selfTest(); %% 'Too many input arguments.' error

end

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classdef MyClass

properties (GetAccess = protected, SetAccess = protected)

m_myMat = eye(3);

m_myVec = zeros(1,3);

end

methods

function obj = MyClass(aMat, aVec) % constructor with parameters

m_myMat = aMat;

m_myVec = aVec;

end

function setMat(obj, aMat)

obj.m_myMat = aMat;

end

function setVec(obj, aVec)

obj.m_myVec = aVec;

end

function aMat = mat(obj)

aMat = obj.m_myMat;

end

function aVec = vec(obj)

aVec = obj.m_myVec;

end

function selfTest(obj) %% 'Too many input arguments.' error before entering this line

a = MyClass(eye(3), ones(1,3));

b = a;

b.setMat(magic(3));

b.setVec([0 0 1]);

b.mat() %% This line displays eye(3) instead of magic(3)

b.vec() %% This line displays [0 0 0] instead of magic(3)

end

end %% end of methods

end %% end of classdef MyClass

Answer 1

[Yongjian Feng]

Several issues here.

• Subclass of handle. This makes your life easier;
• obj is 'this'. All the none-static methods need to use obj as the first argument.

classdef	MyClass <handle
    
    properties (GetAccess = protected, SetAccess = protected)
        m_myMat		= eye(3);
        m_myVec		= zeros(1,3);
    end
    
    methods
        
        function	obj = MyClass(aMat, aVec)		%	constructor with parameters
            obj.m_myMat	= aMat;
            obj.m_myVec	= aVec;
        end
        
        function	setMat(obj, aMat)
            obj.m_myMat	= aMat;
        end
        
        function	setVec(obj, aVec)
            obj.m_myVec	= aVec;
        end
            
        function	aMat = mat(obj)
            aMat	= obj.m_myMat;
        end
          
        function	aVec = vec(obj)
            aVec	= obj.m_myVec;
        end
      
        function	selfTest(obj)      
            % What do you want to do here?
        end
    end		%%  end of methods
end			%%  end of classdef MyClass

[Ming Chao]

Your answer helped solve my problems. Thanks Yongjian!