SecantSolve.C

Go to the documentation of this file.

//* This file is part of the MOOSE framework
//* https://mooseframework.inl.gov
//*
//* All rights reserved, see COPYRIGHT for full restrictions
//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
//*
//* Licensed under LGPL 2.1, please see LICENSE for details
//* https://www.gnu.org/licenses/lgpl-2.1.html

#include "SecantSolve.h"

#include "Executioner.h"
#include "FEProblemBase.h"
#include "NonlinearSystem.h"
#include "AllLocalDofIndicesThread.h"
#include "Console.h"

InputParameters
SecantSolve::validParams()
{
  InputParameters params = FixedPointSolve::validParams();

  return params;
}

SecantSolve::SecantSolve(Executioner & ex) : FixedPointSolve(ex)
{
  _transformed_pps_values.resize(_transformed_pps.size());
  for (size_t i = 0; i < _transformed_pps.size(); i++)
    _transformed_pps_values[i].resize(4);
  _secondary_transformed_pps_values.resize(_secondary_transformed_pps.size());
  for (size_t i = 0; i < _secondary_transformed_pps.size(); i++)
    _secondary_transformed_pps_values[i].resize(4);
}

void
SecantSolve::allocateStorage(const bool primary)
{
  findTransformedSystem(primary);
  if (!_transformed_sys)
    return;

  // TODO: We would only need to store the solution for the degrees of freedom that
  // will be transformed, not the entire solution.
  // Store solution vectors for the two previous points and their evaluation
  if (primary)
  {
    _xn_m1_tagid =
        _problem.addVectorTag(Moose::PREVIOUS_FP_SOLUTION_TAG, Moose::VECTOR_TAG_SOLUTION);
    _fxn_m1_tagid = _problem.addVectorTag("fxn_m1", Moose::VECTOR_TAG_SOLUTION);
    _xn_m2_tagid = _problem.addVectorTag("xn_m2", Moose::VECTOR_TAG_SOLUTION);
    _fxn_m2_tagid = _problem.addVectorTag("fxn_m2", Moose::VECTOR_TAG_SOLUTION);

    _transformed_sys->needSolutionState(1, Moose::SolutionIterationType::FixedPoint, PARALLEL);
    _transformed_sys->addVector(_fxn_m1_tagid, false, PARALLEL);
    _transformed_sys->addVector(_xn_m2_tagid, false, PARALLEL);
    _transformed_sys->addVector(_fxn_m2_tagid, false, PARALLEL);
  }
  else
  {
    _secondary_xn_m1_tagid = _problem.addVectorTag("secondary_xn_m1", Moose::VECTOR_TAG_SOLUTION);
    _secondary_fxn_m1_tagid = _problem.addVectorTag("secondary_fxn_m1", Moose::VECTOR_TAG_SOLUTION);
    _secondary_xn_m2_tagid = _problem.addVectorTag("secondary_xn_m2", Moose::VECTOR_TAG_SOLUTION);
    _secondary_fxn_m2_tagid = _problem.addVectorTag("secondary_fxn_m2", Moose::VECTOR_TAG_SOLUTION);

    _transformed_sys->addVector(_secondary_xn_m1_tagid, false, PARALLEL);
    _transformed_sys->addVector(_secondary_fxn_m1_tagid, false, PARALLEL);
    _transformed_sys->addVector(_secondary_xn_m2_tagid, false, PARALLEL);
    _transformed_sys->addVector(_secondary_fxn_m2_tagid, false, PARALLEL);
  }
}

void
SecantSolve::saveVariableValues(const bool primary)
{
  TagID fxn_m1_tagid;
  TagID xn_m1_tagid;
  TagID fxn_m2_tagid;
  TagID xn_m2_tagid;
  if (primary)
  {
    fxn_m1_tagid = _fxn_m1_tagid;
    xn_m1_tagid = _xn_m1_tagid;
    fxn_m2_tagid = _fxn_m2_tagid;
    xn_m2_tagid = _xn_m2_tagid;
  }
  else
  {
    fxn_m1_tagid = _secondary_fxn_m1_tagid;
    xn_m1_tagid = _secondary_xn_m1_tagid;
    fxn_m2_tagid = _secondary_fxn_m2_tagid;
    xn_m2_tagid = _secondary_xn_m2_tagid;
  }

  // Check to make sure allocateStorage has been called
  mooseAssert(fxn_m1_tagid != Moose::INVALID_TAG_ID,
              "allocateStorage has not been called with primary = " + Moose::stringify(primary));
  mooseAssert(xn_m1_tagid != Moose::INVALID_TAG_ID,
              "allocateStorage has not been called with primary = " + Moose::stringify(primary));
  mooseAssert(fxn_m2_tagid != Moose::INVALID_TAG_ID,
              "allocateStorage has not been called with primary = " + Moose::stringify(primary));
  mooseAssert(xn_m2_tagid != Moose::INVALID_TAG_ID,
              "allocateStorage has not been called with primary = " + Moose::stringify(primary));

  // Save previous variable values
  NumericVector<Number> & solution = _transformed_sys->solution();
  NumericVector<Number> & fxn_m1 = _transformed_sys->getVector(fxn_m1_tagid);
  NumericVector<Number> & xn_m1 = _transformed_sys->getVector(xn_m1_tagid);
  NumericVector<Number> & fxn_m2 = _transformed_sys->getVector(fxn_m2_tagid);
  NumericVector<Number> & xn_m2 = _transformed_sys->getVector(xn_m2_tagid);

  // Advance one step
  xn_m2 = xn_m1;

  // Before a solve, solution is a sequence term, after a solve, solution is the evaluated term
  // Primary is copied back by _transformed_sys->copyPreviousFixedPointSolutions()
  if (!primary)
    xn_m1 = solution;

  // Since we did not update on the 0th iteration, the solution is also the previous evaluated term
  const unsigned int it = primary ? _fixed_point_it : _main_fixed_point_it;
  if (it == 1)
    fxn_m2 = solution;
  // Otherwise we just advance
  else
    fxn_m2 = fxn_m1;
}

void
SecantSolve::savePostprocessorValues(const bool primary)
{
  const std::vector<PostprocessorName> * transformed_pps;
  std::vector<std::vector<PostprocessorValue>> * transformed_pps_values;
  if (primary)
  {
    transformed_pps = &_transformed_pps;
    transformed_pps_values = &_transformed_pps_values;
  }
  else
  {
    transformed_pps = &_secondary_transformed_pps;
    transformed_pps_values = &_secondary_transformed_pps_values;
  }
  const unsigned int it = primary ? _fixed_point_it : _main_fixed_point_it;

  // Save previous postprocessor values
  for (size_t i = 0; i < (*transformed_pps).size(); i++)
  {
    // Advance one step
    (*transformed_pps_values)[i][3] = (*transformed_pps_values)[i][1];

    // Save current value
    // Primary: this is done before the timestep's solves and before timestep_begin transfers,
    // so the value is the result of the previous Secant update (xn_m1)
    // Secondary: this is done after the secondary solve, but before timestep_end postprocessors
    // are computed, or timestep_end transfers are received.
    // This value is the same as before the solve (xn_m1)
    (*transformed_pps_values)[i][1] = getPostprocessorValueByName((*transformed_pps)[i]);

    // Since we did not update on the 1st iteration, the pp is also the previous evaluated term
    if (it == 2)
      (*transformed_pps_values)[i][2] = (*transformed_pps_values)[i][1];
    // Otherwise we just advance
    else
      (*transformed_pps_values)[i][2] = (*transformed_pps_values)[i][0];
  }
}

bool
SecantSolve::useFixedPointAlgorithmUpdateInsteadOfPicard(const bool primary)
{
  // Need at least two evaluations to compute the Secant slope
  if (primary)
    return _fixed_point_it > 0;
  else
    return _main_fixed_point_it > 0;
}

void
SecantSolve::transformPostprocessors(const bool primary)
{
  if ((primary ? _fixed_point_it : _main_fixed_point_it) < 2)
    return;

  Real relaxation_factor;
  const std::vector<PostprocessorName> * transformed_pps;
  std::vector<std::vector<PostprocessorValue>> * transformed_pps_values;
  if (primary)
  {
    relaxation_factor = _relax_factor;
    transformed_pps = &_transformed_pps;
    transformed_pps_values = &_transformed_pps_values;
  }
  else
  {
    relaxation_factor = _secondary_relaxation_factor;
    transformed_pps = &_secondary_transformed_pps;
    transformed_pps_values = &_secondary_transformed_pps_values;
  }

  // Relax postprocessors for the main application
  for (size_t i = 0; i < (*transformed_pps).size(); i++)
  {
    // Get new postprocessor value
    const Real fxn_m1 = getPostprocessorValueByName((*transformed_pps)[i]);
    const Real xn_m1 = (*transformed_pps_values)[i][1];
    const Real fxn_m2 = (*transformed_pps_values)[i][2];
    const Real xn_m2 = (*transformed_pps_values)[i][3];

    // Save fxn_m1, received or computed before the solve
    (*transformed_pps_values)[i][0] = fxn_m1;

    // Compute and set relaxed value
    Real new_value = fxn_m1;
    if (!MooseUtils::absoluteFuzzyEqual(fxn_m1 - xn_m1 - fxn_m2 + xn_m2, 0))
      new_value = xn_m1 - (fxn_m1 - xn_m1) * (xn_m1 - xn_m2) / (fxn_m1 - xn_m1 - fxn_m2 + xn_m2);

    // Relax update if desired
    new_value = relaxation_factor * new_value + (1 - relaxation_factor) * xn_m1;

    _problem.setPostprocessorValueByName((*transformed_pps)[i], new_value);
  }
}

void
SecantSolve::transformVariables(const std::set<dof_id_type> & target_dofs, const bool primary)
{
  Real relaxation_factor;
  TagID fxn_m1_tagid;
  TagID xn_m1_tagid;
  TagID fxn_m2_tagid;
  TagID xn_m2_tagid;
  if (primary)
  {
    relaxation_factor = _relax_factor;
    fxn_m1_tagid = _fxn_m1_tagid;
    xn_m1_tagid = _xn_m1_tagid;
    fxn_m2_tagid = _fxn_m2_tagid;
    xn_m2_tagid = _xn_m2_tagid;
  }
  else
  {
    relaxation_factor = _secondary_relaxation_factor;
    fxn_m1_tagid = _secondary_fxn_m1_tagid;
    xn_m1_tagid = _secondary_xn_m1_tagid;
    fxn_m2_tagid = _secondary_fxn_m2_tagid;
    xn_m2_tagid = _secondary_xn_m2_tagid;
  }

  NumericVector<Number> & solution = _transformed_sys->solution();
  NumericVector<Number> & xn_m1 = _transformed_sys->getVector(xn_m1_tagid);
  NumericVector<Number> & fxn_m2 = _transformed_sys->getVector(fxn_m2_tagid);
  NumericVector<Number> & xn_m2 = _transformed_sys->getVector(xn_m2_tagid);

  // Save the most recent evaluation of the coupled problem
  NumericVector<Number> & fxn_m1 = _transformed_sys->getVector(fxn_m1_tagid);
  fxn_m1 = solution;

  for (const auto & dof : target_dofs)
  {
    // Avoid 0 denominator issue
    Real new_value = fxn_m1(dof);
    if (!MooseUtils::absoluteFuzzyEqual(solution(dof) - xn_m1(dof) - fxn_m2(dof) + xn_m2(dof), 0))
      new_value = xn_m1(dof) - (solution(dof) - xn_m1(dof)) * (xn_m1(dof) - xn_m2(dof)) /
                                   (solution(dof) - xn_m1(dof) - fxn_m2(dof) + xn_m2(dof));

    // Relax update
    new_value = relaxation_factor * new_value + (1 - relaxation_factor) * xn_m1(dof);

    solution.set(dof, new_value);
  }
  solution.close();
  _transformed_sys->update();
}

void
SecantSolve::printFixedPointConvergenceHistory(Real initial_norm,
                                               const std::vector<Real> & timestep_begin_norms,
                                               const std::vector<Real> & timestep_end_norms) const
{
  _console << "\n 0 Secant initialization |R| = "
           << Console::outputNorm(std::numeric_limits<Real>::max(), initial_norm) << '\n';

  Real max_norm_old = initial_norm;
  for (unsigned int i = 0; i <= _fixed_point_it; ++i)
  {
    Real max_norm = std::max(timestep_begin_norms[i], timestep_end_norms[i]);
    std::stringstream secant_prefix;
    if (i < 1)
      secant_prefix << " Secant initialization |R| = ";
    else
      secant_prefix << " Secant step           |R| = ";

    _console << std::setw(2) << i + 1 << secant_prefix.str()
             << Console::outputNorm(max_norm_old, max_norm) << '\n';
    max_norm_old = max_norm;
  }
}