Pass newly created object's function to a timer object

I created a class which reads a file as soon as an object is created. In order to display the progress of reading process, I created a public function (which I prefered to be private by the way). Let's call this function writeProgress,

However, after starting the timer, I receive an warning message:

"feval: Undefined function or method 'obj.writeProgress' for input arguments of type 'timer'".

The timer has been initialized like this:

t = timer('TimerFcn',@obj.writeProgress,'Period',1,'ExecutionMode','fixedDelay');

How can I pass the function "writeProgress"? Write progress needs to be a class member as it has to access private data and I'd rather prefer it to be private itself.

Answer 1

[Sean de Wolski]

Here is a class that does what you want from the description above. The only difference is that I placed the call to writeProgeress inside of an anonymous function.

What else is different with it from your class?

classdef WP < handle
  properties 
      x
      y
  end
  methods
      function obj = WP(varargin)
          obj.x = pi;
          obj.y = 'hello world';
          t = timer('TimerFcn',@(src,evt)obj.writeProgress,'Period',1,'ExecutionMode','fixedDelay');
          start(t)
      end            
  end
  methods (Access=private)
      function writeProgress(obj)
          disp(obj.x);
          disp(obj.y);
      end
  end
end

[Vincent]

Worked just fine (except for Access='private' <- apostrophes). Only difference to my timer-call is (src,evt). What does it do and why is it needed?

[Sean de Wolski]

Most callbacks automatically receive two inputs: the source of the callback and some event data. These need to be accounted for. In the above, I accounted for them with the anonymous function and then threw them away because we didn't need them.

Creating Callbacks

[Vincent]

well, thanks a lot!