MATLAB: How to reset persistent variables in nested functions

Question

I can't figure out whether this is a MATLAB bug or a PEBKAC issue, but in case of the latter, I figured I'd check here first.

I have a nested function with some persistent variables. Occasionally, when some condition is met in the outer function, I wish to be able to reset these variables to their initial state (i.e. [ ]). It doesn't seem to work to use "clear MyNestedFunc" in the outer function:

function MyFunc()
    MyNestedFunc();
    MyNestedFunc();
    clear MyNestedFunc
    MyNestedFunc();
    function MyNestedFunc()
        persistent foo
        if isempty(foo)
            foo = 1;
        else
            foo = foo + 1;
        end
        disp(foo)
    end
end

My desired output from this is 1, 2, 1, but what I get is 1, 2, 3.

The way to do it so that it works is apparently to make foo a persistent variable in the outer function, but for reasons of code clarity and organization I'd really prefer to encapsulate it inside the nested function if I could.

Is this a MATLAB bug because "clear MyNestedFunc" doesn't have the expected effect, or am I trying to do something in the wrong way?

Answer 1

A hokey workaround:

function MyFunc()
      resetfoo = false;  % issued once at beginning.
      MyNestedFunc();
      MyNestedFunc();
      MyNestedFunc();
      resetfoo = true;  % whenever we want to reset foo.
      MyNestedFunc();
      MyNestedFunc();
      MyNestedFunc();
      function MyNestedFunc()
          persistent foo
          if resetfoo || isempty(foo)
              foo = 1;
              resetfoo = false;
          else
              foo = foo + 1;
          end
          disp(foo)
      end
  end