MATLAB: Syntax errors symbolic to logical


I am trying to do a backtracking line search algorithm for a stepest decent problem. This bascial means I need to keep using the gradiant and eventually the hessian alot. But I am trying to compare the operators to be able to compare and I just cant get it. below is my code and a photo of what i am trying to do.

Best Answer

  • You missed the point that requires that the gradient of f be evaluated at x. You are taking the symbolic gradient of f into gf, but you are not evaluating it at x.
    Note: if you have a symbolic gradient gf, then you do not need to re-calculate it every iteration: you can calculate gf once and evaluate gf with the current x at every step.