Hello, I’ve been using the default newton line search nonlinear solver in petsc. I recently discovered that the default line search method is bt – backtracking. I have two questions.
1. How exactly does the backtracking line search use the L2 norm of the function to modify the newton step? What is the formula? 2. Why is backtracking default? I would think that the basic method, which is a standard Newton method, would be default. -Justin