This function takes a function and returns a function that counts how many times the function has been called.

make_counting_function.m

%% make_counting_function:
function [g] = make_counting_function(f)
    count = 0;

    function [varargout] = counting_function(varargin)
        if (nargin == 0)
            varargout = {count};
        else
            count = count + 1;
            varargout = {f(varargin{:})};
        end
    end

    g = @counting_function;
end