Trying to make a recursive tree function that calls on itself using OOP, where the object is a turtle.

I have a separate turtle class created already. Here is my code.

function [obj] = tree(obj,n) % Creates tree to the order n

    obj = Turtle();
    t = Turtle();
    a = 60; % angle in degrees
    d = 4; % distance turtle travels

    % If n is 0, 
    if n <= 0
    % do nothing.
        t = t.fd(0);
    % Otherwise, 
    else 
    % drive forward d,
        t = t.fd(d);
    % turn left a degrees,
        t = t.lt(a);
    % draw a level n-1 tree, 
        obj = tree(n-1)
    % turn right 2a degrees, 
        t = t.rt(2*a);
    % draw a level n-1 tree, 
        obj = tree(n-1)
    % turn left a degrees, 
        t = t.lt(a);
    % and drive backward d
        t = t.bk(d);
    end
  end

Matlab gives me an error saying "Undefined function or variable 'Turtle'". Does anyone know how to fix this?

[Geoff Hayes]

Kyle - you indicate that you want to make a recursive tree function that calls on itself but your function tree never calls itself. It does call the function (or is this an object that you are instantiating?) called Turtle. The MATLAB error message is indicating that this function (or class) cannot be found within the MATLAB search path. Is Turtle something that you have written? If so, then you need to add this file to the search path so that your tree function can find it.