how to count the number of function calls without modifying it by inserting a counter ?

Hi, for example in ga(...), the count of objective function calls is provided, but not that of the constraint function. My unsatisfactory solution is, in the main program, to insert a global variable to count and another to reset the counter :

      global constr_count 
      global reset_constr_count    % = 1 to reset
      ...
      reset_constr_count = 1;
      [x, fval, exitflag, output] = ga(handle_obj, I, ...
          [], [], [], [], lx, ux, @my_constraint_function, options_ga);

and to insert those lines in the constraint function :

      function [g, h] = my_constraint_function(x)
      ...
      % counter constr_count of calls to this function :
      global constr_count reset_constr_count;
      persistent count;
      if isempty(count) || reset_constr_count == 1
          count = 1;
          reset_constr_count = 0;
      else
          count = count + 1;
      end
      constr_count = count;

With this solution, I have to modify all my pre existing constraint functions, which is a hard task. Is there an easier way to count (not only in that ga example) ? Thank you !

Answer 1

[Matt J]

If you just provide a wrapper for your constraint function to ga(), then you can handle the counter there instead of changing your legacy constraint code. Also, if you make the wrapper a Nested Function like below, then there will be no need for global, persistent, or reset variables, and the control logic simplifies to one line:

 function do_Optimization

   constr_count=0; %externally scoped variable

   x=ga(@fitnessfun,nVars,...,@my_constraint_wrapper);

        function [g, h] = my_constraint_wrapper(x)  %NESTED

           constr_count = constr_count +1 ;

            [g,h]= my_constraint_function(x);

        end

 end

Answer 2

[Guillaume]

Use the Profiler which gives you the number of calls among other things.