MatLab operator overloading

Question

Possible Duplicate:
How do properties work in Object Oriented MATLAB?

I have been using MatLab for quite some time but started using OOP just recently.

I have a class that is a simple linked list (it can be anything really). A few methods are declared in the class. Is it possible for the methods to modify the instance from which those are called?

instance.plotData() cannot modify any properties of the instance .

I have to return the instance for the function to actually have some effect on the instance itself:

instance = instance.plotData();

This seems really cumbersome. Is there a better way of achieving the task?

Addition:

classdef handleTest < handle

  properties
      number
  end

  methods
      function addNode(this)
          a = length(this);
          this(a+1) = handleTest;
      end
  end
end

If i call:

x = handleTest
x.addNode()

then x has still only one node.

score 1 · Accepted Answer · answered Aug 28 '12 at 22:40

1

A possible solution is to derive from the handle class, i.e. use something like

classdef YourClass < handle
    function plotData(obj)
        ... modify the obj here ...
    end
end

However, this also has implications, if you copy the instance, i.e. if you do an

a = YourClass(...);
b = a;

then b is an alias for a and whenever you change a, you also modify b and vice versa (meaning the data is only stored once in the background).

There is the Matlab documentation for handle classes and the difference to value classes.

answered Aug 28 '12 at 22:40

Mehrwolf

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Thanks, Mehrwolf. Is it possible to add instances of class to an already defined instance that is controlled with such a handle? For example, I have a "node" class. n(1) = node(); is the initialization line of the class instance. I would like to add more nodes to the vector -- a function would then execute the following command: n(2) = node(); and then modify the parameters of the node. The Handle version does not seem to work. Am I misrepresenting the handle operator? Thanks, SunnyBuy – user02222022 Aug 29 '12 at 16:50
@SunnyBoyNY: Could you ask this as a new question and post a short code example of your `node`? I think, I do not get completely, what you try to do. – Mehrwolf Aug 29 '12 at 17:08
let me edit the question – user02222022 Aug 29 '12 at 21:52
@SunnyBoyNY: Ok, no I get the point. I would not try to add the handle to itself (inside the class) but instead create a vector of `handleTest`, which is stored somewhere in your calling program. If you want to wrap this vector, you could create another class e.g. `handleList`. This class has an `addNode()` that adds an instance of `handleTest` to the internal vector. – Mehrwolf Aug 30 '12 at 06:50

MatLab operator overloading

1 Answers1