Newton's method for solving a system of nonlinear equations, see http://en.wikipedia.org/wiki/Newton's_method
Newton(X,F,X0) solves nonlinear system F(x)=0 by Newton's method, using the given initial approximation X0. The derivative (Jacobian) is evaluated symbolically. The iterations are performed numerically.
The included demo NewtonDemoRunMe.m shows how to run the Newton.m function. E.g., it creates a slide-show and a movie, illustrating the behavior of the iterates.
The code works in Symbolic Math Toolbox 5.7 (R2011b). Previous versions of the toolbox may not support creating symbolic vectors this way. There may be other issues, too, with prior unsupported versions of the toolbox.
Hey,man! X=sym('X',[2 1]); is not a valid command..... Tried your algorithm, but did not work.
added a conversion to a toolbox
Multiple improvements and updates.
Bug fixes in Newton.m and a new script NewtonDemoRunMe.m with examples.