How to get Dependent Property depending on properties of objects of different class

See the code below:

Ex_ObjA.m-->

classdef Ex_ObjA

      properties
          a
      end

      methods
          function Obj=Ex_ObjA(t)
             Obj.a = t; 
          end
      end    
  end

Ex_ObjBC.m-->

classdef Ex_ObjBC
    properties
        b
    end

      properties (Dependent = true, SetAccess = public)
          c
      end    

      methods
          function Obj=Ex_ObjBC(t)
             Obj.b = t; 
          end

          function c=get.c(Obj,s1) % error: Get methods must have exactly one input
              c = Obj.b + s1.a;
          end
      end
  end

I tried to do following:

s1 = Ex_ObjA(2);

s2 = Ex_ObjBC(3);

s2.c

Not successful, because "Get methods must have exactly one input". So I can pass the s1.a to Ex_ObjBC to get s1.c?

Much appreciation!!!

Answer 1

[Matt J]

There's no apparent reason why c should be a property, Dependent or otherwise. You could just write the class this way,

classdef Ex_ObjBC
    properties
        b
    end

        methods

            function Obj=Ex_ObjBC(t)
               Obj.b = t; 
            end

            function out=c(Obj,s1) 

                out = Obj.b + s1.a;

            end
        end
    end

[J. Hu]

Seems I understood dependent properties incorrectly. Is it true that dependent properties are those depend on the class's own primary properties?

[Matt J]

Dependent properties are properties that you don't want to store actual data for. You do derive their values (in get() operations) on the fly from other properties, but class functions are also ways of deriving values from class properties (and other input). It's not clear why c should have property status in your application.

[J. Hu]

Thanks for your explanation. Since c is a value depending on properties of different classes, what you would suggest placing the function to get c - in one of the classes of the properties it depends on or none of them? For example, if c depends on 10 properties, 9 of those belong to one class A and one comes from another class B. So c is HIGHLY depending on the class A - and that is the reason I wanted to put it is a dependent property of class A.

Upon your suggestion, I did define the function like c=getc(Obj,s1) and call it using s2.getc(s1). It works but I do not understand why the inputs have to be like that, one is (Obj,s1) in the function definition and the caller is getc(s1) - not the same. I know it works but why? Seems Obj is internal input of s2. Thanks...

[Matt J]

s2.getc(s1) is equivalent to getc(s2,s1)