Editing a function to return a value that shows how many times a recursive function is called

I have two separate functions. They are both used to calculate a Fibonacci number. Here is the first

function [result] = myFibonacci1(n)

   if (n == 0)
      result = 0;
   elseif (n == 1)
      result = 1;
   else
      result = myFibonacci1(n - 2) + myFibonacci1(n - 1);
   end
end

And here is the second

function [result] = myFibonacci2(n)

   % Create a temporary array 'stored' to store results already
   % calculated, the Fibonacci value for n is stored in array
   % location n + 1 (to allow us to store the value for n = 0 in a
   % location.) So, Fibonacci(0) is stored in stored(1),
   % Fibonacci(1) is stored in stored(2), etc.

   stored = ones(1, n + 1) * -1;

   stored(1) = 0;
   stored(2) = 1;

   function [hResult] = helper(a)

      if (stored(a + 1) ~= -1)
         hResult = stored(a + 1);
      else
         hResult = helper(a - 2) + helper(a - 1);
         stored(a + 1) = hResult;
      end
   end

   result = helper(n)

end

My goal is to edit these both of these functions so they also return the number of times a recursive functi0n is called.

Any ideas?

Answer 1

[Jiawei Gong]

function [f,count] = MyFib(n)
count = 1;
if n==1 || n==2
    f = 1;
else
    [f1,count1] = MyFib(n-1);
    [f2,count2] = MyFib(n-2);
    f = f1+f2;
    count = count+count1+count2; % count itself and two branches
end
end

Results:

>> [f,callN] = MyFib(6)
f =
     8
callN =
    15

Answer 2

[Jos (10584)]

You can add a second output argument

function [result, CallN] = myFunction(n, CallN)

if nargin==1,
   CallN = 1 ;
else
   CallN = CallN + 1 ;
end

...

Answer 3

[James Tursa]

See this link:

http://www.mathworks.com/matlabcentral/answers/195865-fibonacci-program-makes-matlab-go-busy-forever

You could be waiting a VERY, VERY, LONG time for your answer ...

[Noah Swiston]

I understand this is a bad method to calculate the fibonacci number. However, it was assigned to me just to add to the function to calculate how many times the recursion takes place, and then add that as an output argument as well. Any clue how to calculate how many time it is called?

[James Tursa]

Jos has given you one method. Could also use a global variable for the counter if you don't want to change argument lists.