Problems with parfor in class method

If I run

F=Foo(1);
F.A=pi;
F.bar();

where

classdef Foo
    properties
        A;
        sz;
    end
    methods
        function obj = Foo(sz)
            obj.sz=sz;
        end
        function obj=set.A(obj,A)
            if size(A)==obj.sz
                obj.A=reshape(A,numel(A),[]);
            end
        end
        function []=bar(obj)
            parfor i=1:1
                obj.A(1);
            end
        end
    end
end

then I get

Error using Foo/bar (line 16)
Index exceeds matrix dimensions.

Error in test (line 4)
F.bar();

The error disappears when I replace the parfor-loop with a regular for-loop.

I get a warning in my editor on the line "if size(A)==obj.sz", saying "A set method for a non-dependent property should not access another property". However, if I make the variable "A" dependent, then I can't define a set method.

EDIT: I found out that the error also disappears when I declare "sz" first, and then "A".

Answer 1

[Matt J]

Very strange indeed. However, the following seems to solve all problems.

     classdef Foo 

      properties
          Adata;
          sz;
      end
      properties (Dependent)
         A; 
      end

      methods
          function obj = myclass(sz)
              obj.sz=sz;
          end

          function obj=set.A(obj,val)
              if isequal(size(val), obj.sz) || isscalar(val) 
                  obj.Adata=val(:);
              else
                  obj.Adata=val;
              end
          end

          function A=get.A(obj)
              A=obj.Adata;

          end

            function bar(obj)

                parfor i=1:1
                    obj.A(1),
                end
            end
        end
    end

[Bananach]

It works, but it is not optimal. I would like to let the user know about wrong assignments when they are done, not when they are used.

So is this a bug? Should I report it somewhere?

[Bananach]

Also, note my edit: I can fix my code by declaring "sz" first

[Matt J]

I've edited my post with a variation that does the reshaping in the set.A method.

It might be a bug, and certainly wouldn't hurt to report. My theory, though, is that the warning you were getting about set.A is somehow the cause of the parfor error. When A is converted to a Dependent property with proper set/get methods defined, I see no error thrown by bar().