MATLAB: OOP: matlab class as a property of another class

classoopproperties

Hi, I'm a newbie to matlab. The class individual as follows has a property named Genotype. I need this property to be another class which would have some other properties a constructor and functions. The property Genotype should correspond to the class genotype.

This can be easily achieved in other OO languages as java or c++ since they are type constrained. I don't understand how to do this with matlab. Any help would be appreciated

classdef Individual

    properties
        Genotype
    end % properties

    methods
        function 
        end % function

    end % methods

end % classdef

classdef Genotype

    properties
        X
        Y
        Z
    end % properties
    methods
        function 
        end % function
    end % methods

end % classdef

Best Answer

I think the following should work for setting this property from the Constructor function. The following assumes that you have created at Genotype object called Genotype_obj.

I might recommend renaming the Genotype parameter of Individual to something else to distinguish it from the class name, but I think Matlab is smart enough to know the difference.

function obj = Individual(Genotype_obj)
assert(isa(Genotype_obj,'Genotype'),'Individual Constructor Error:  Genotype_obj is of class %s, not a Genotype object.', class(Genotype_obj));
obj.Genotype = Genotype_obj;
return

The idea is to pass the object to the constructor and then check that it is the right type of object. This could also be handled in a Set() function. You might want to perform this error checking in a Set() function in addition to this code if you will ever be setting the property that way.

Good luck,

Eric

Related Solutions

MATLAB: Changing variable (properties in class) by method

Your class is a value class as opposed to a handle class. See this documentation page for a description of the differences between the two. The "Modifying Value Objects in Functions" and "Modifying Handle Objects in Functions" sections on that documentation page describe what happens when you modify properties of an instance of each kind of class in a function or method. So you can either:

Define the methods in your value class to return the modified object, and call the methods with the object as both input and output.
Change your class to a handle class.

MATLAB: Is calling a superclass constructor after a use of the object not allowed

I can only speculate as to why it would not be allowed, but I assume there are hazards in using an object that is not finished being constructed...like feeding a baby that is only half way through being born, or driving a car that’s only half assembled.

Below is how I would re-implement. In your original design, it doesn't make sense to me that the classB constructor should have to set x if it has already been set in classA.

classdef superclass
    
    %% PROPERTIES
    properties 
        x;
        y;
    end
    
end

classdef classA < superclass
    
    %% PROPERTIES
    properties
        a
    end
    
    properties (Access=private)
        z
    end
    
    %% METHODS
    methods
        % Constructor


        function obj = classA(a,z,y)
            obj.x = a*z;
            obj.a = a;
            obj.z = z;
            if nargin>2
             obj.y=y;   
            end
        end
    end
    
end

classdef classB < superclass
    
    %% PROPERTIES
    properties
        b
    end
    properties (Access=private)
        z
    end
    
    %% METHODS
    methods
        % Constructor
        function obj = classB(b,z,x)
            obj.y = z+b;
            obj.b = b;
            obj.z = z;
            if nargin>2
               obj.x=x; 
            end
        end
    end
    
end

classdef subclass < classA & classB
    
    %% METHODS
    methods
        % Constructor
        function obj = subclass(a,b,z)
            obj@classA(a,z);  %set x but not y
            obj@classB(b,z);  %set y but not x  
        end
    end
    
end

Best Answer

Related Solutions

MATLAB: Changing variable (properties in class) by method

MATLAB: Is calling a superclass constructor after a use of the object not allowed

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