nonlinear stepsize control

On an Elliptical Trust-Region Procedure for Ill-Posed Nonlinear Least-Squares Problems

  • Stefania Bellavia
  • Elisa Riccietti
    • Categories Nonlinear Systems and Least-Squares Tags , , , ,

    In this paper we address the stable numerical solution of ill-posed nonlinear least-squares problems with small residual. We propose an elliptical trust-region reformulation of a Levenberg-Marquardt procedure. Thanks to an appropriate choice of the trust-region radius, the proposed procedure guarantees an automatic choice of the free regularization parameters that, together with a suitable stopping criterion, … Read more

    On an adaptive regularization for ill-posed nonlinear systems and its trust-region implementation

  • Stefania Bellavia
  • Benedetta Morini
  • Elisa Riccietti
    • Categories Nonlinear Optimization Tags , , ,

    In this paper we address the stable numerical solution of nonlinear ill-posed systems by a trust-region method. We show that an appropriate choice of the trust-region radius gives rise to a procedure that has the potential to approach a solution of the unperturbed system. This regularizing property is shown theoretically and validated numerically. Citation Dipartimento … Read more