MATLAB: Overloaded method defined in class definition, not working

classmethodoopoverloaded operator

Hi all,

I defined a method 'find' in a class definition('tree'). Upon doing 'help find' I can see it under the Overloaded Methods heading ('tree/find'). But when I try to use it MATLAB gives me error saying "Method 'find' is not defined for class 'tree' or is removed from MATLAB's search path." Would anyone have any idea what the problem might be? Thanks.

Best Answer

I made a classdef-file according to you description. It works as expected (R2013a).

    >> t= cssm_tree
    t = 
      cssm_tree with no properties.
    >> t.find('abc')
    cssm_tree/find
    ans =
        17
    >> help find
      ....
      Overloaded methods:
         tree/find
         mtree/find
         cssm_tree/find
         ...

where

    classdef    cssm_tree < handle
        methods
            function    ix = find( this, f )
                % find is overloaded 
                disp( 'cssm_tree/find' )
                ix = 17;
            end
        end
    end

Related Solutions

MATLAB: How to override inherited methods

You can't do what you asked. If you could, you could relax the property setting validation to the point where your subClass instance wouldn't be a valid superClass instance.

You may be able to do what you want, however. Your superClass's property setter could call a normal instance method that subClass could overload. See the trustedSubclassSetterHelper methods in the attached superClass495080 and subClass495080. That helper doesn't actually set the property (otherwise you get into a loop) but merely provides the updated value. This means that the value would have to be something both superClass495080 (in set.prop1) and subClass495080 (in trustedSubclassSetterHelper) accept as a valid value.

>> Q = superClass495080
Q = 
  superClass495080 with properties:
    prop1: 'Hello!'
    prop2: 'My name is'
>> Q2 = subClass495080
Q2 = 
  subClass495080 with properties:
    prop3: 'Dom.'
    prop1: 'Hello World!'
    prop2: 'My name is'

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: How to override inherited methods

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

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