Line data    Source code

       1              : // Copyright 2024, UChicago Argonne, LLC
       2              : // All Rights Reserved
       3              : // Software Name: NEML2 -- the New Engineering material Model Library, version 2
       4              : // By: Argonne National Laboratory
       5              : // OPEN SOURCE LICENSE (MIT)
       6              : //
       7              : // Permission is hereby granted, free of charge, to any person obtaining a copy
       8              : // of this software and associated documentation files (the "Software"), to deal
       9              : // in the Software without restriction, including without limitation the rights
      10              : // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      11              : // copies of the Software, and to permit persons to whom the Software is
      12              : // furnished to do so, subject to the following conditions:
      13              : //
      14              : // The above copyright notice and this permission notice shall be included in
      15              : // all copies or substantial portions of the Software.
      16              : //
      17              : // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      18              : // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      19              : // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      20              : // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      21              : // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      22              : // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      23              : // THE SOFTWARE.
      24              : 
      25              : #include "neml2/solvers/TrustRegionSubProblem.h"
      26              : #include "neml2/tensors/functions/bmm.h"
      27              : #include "neml2/tensors/functions/bmv.h"
      28              : #include "neml2/tensors/functions/bvv.h"
      29              : #include "neml2/tensors/functions/sqrt.h"
      30              : #include "neml2/tensors/functions/pow.h"
      31              : #include "neml2/tensors/functions/linalg/solve.h"
      32              : 
      33              : namespace neml2
      34              : {
      35            3 : TrustRegionSubProblem::TrustRegionSubProblem(const OptionSet & options)
      36            3 :   : NonlinearSystem(options)
      37              : {
      38            3 : }
      39              : 
      40              : void
      41           18 : TrustRegionSubProblem::reinit(const NonlinearSystem::Res<true> & r,
      42              :                               const NonlinearSystem::Jac<true> & J,
      43              :                               const Scalar & delta)
      44              : {
      45           18 :   _delta = delta;
      46           18 :   _JJ = bmm(J.base_transpose(0, 1), J);
      47           18 :   _Jr = bmv(J.base_transpose(0, 1), r);
      48           18 : }
      49              : 
      50              : void
      51           69 : TrustRegionSubProblem::set_guess(const NonlinearSystem::Sol<false> & x)
      52              : {
      53           69 :   _s = Scalar(x);
      54           69 : }
      55              : 
      56              : void
      57          120 : TrustRegionSubProblem::assemble(NonlinearSystem::Res<false> * residual,
      58              :                                 NonlinearSystem::Jac<false> * Jacobian)
      59              : {
      60          120 :   auto p = -preconditioned_direction(_s);
      61          120 :   auto np = sqrt(bvv(p, p));
      62              : 
      63          120 :   if (residual)
      64           69 :     *residual = NonlinearSystem::Res<false>(1.0 / np - 1.0 / sqrt(2.0 * _delta));
      65              : 
      66          120 :   if (Jacobian)
      67              :     *Jacobian =
      68           51 :         NonlinearSystem::Jac<false>(1.0 / pow(np, 3.0) * bvv(p, preconditioned_solve(_s, p)));
      69          120 : }
      70              : 
      71              : Tensor
      72          189 : TrustRegionSubProblem::preconditioned_solve(const Scalar & s, const Tensor & v) const
      73              : {
      74          189 :   return linalg::solve(_JJ + s * Tensor::identity(v.base_sizes()[0], v.options()), v);
      75              : }
      76              : 
      77              : Tensor
      78          138 : TrustRegionSubProblem::preconditioned_direction(const Scalar & s) const
      79              : {
      80          138 :   return preconditioned_solve(s, _Jr);
      81              : }
      82              : } // namespace neml2