18300593117

Committed 06 Oct 2025 10:47PM UTC coverage: 74.862% (-0.2%) from 75.031%

Build # 18300593117

Build Type

push

github

Committed by

web-flow

Commit Message

Merge pull request #759 from wdhawkins/performance

Sweep performance optimizations

Coverage Stats

294 of 302 new or added lines in 15 files covered. (97.35%)

334 existing lines in 80 files now uncovered.

17788 of 23761 relevant lines covered (74.86%)

61852783.95 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

75.98

/modules/diffusion/diffusion_mip_solver.cc

// SPDX-FileCopyrightText: 2024 The OpenSn Authors <https://open-sn.github.io/opensn/>
// SPDX-License-Identifier: MIT

#include "modules/diffusion/diffusion_mip_solver.h"
#include "modules/linear_boltzmann_solvers/lbs_problem/acceleration/acceleration.h"
#include "modules/linear_boltzmann_solvers/lbs_problem/lbs_structs.h"
#include "framework/mesh/mesh_continuum/mesh_continuum.h"
#include "framework/math/spatial_discretization/finite_element/finite_element_data.h"
#include "framework/math/spatial_discretization/spatial_discretization.h"
#include "framework/math/spatial_discretization/finite_element/unit_cell_matrices.h"
#include "framework/math/functions/function.h"
#include "framework/runtime.h"
#include "framework/logging/log.h"
#include "framework/utils/timer.h"
#include <utility>

namespace opensn
{

DiffusionMIPSolver::DiffusionMIPSolver(std::string name,
                                       const opensn::SpatialDiscretization& sdm,
                                       const UnknownManager& uk_man,
                                       std::map<uint64_t, BoundaryCondition> bcs,
                                       MatID2XSMap map_mat_id_2_xs,
                                       const std::vector<UnitCellMatrices>& unit_cell_matrices,
                                       const bool suppress_bcs,
                                       const bool verbose)
  : DiffusionSolver(std::move(name),
                    sdm,
                    uk_man,
                    std::move(bcs),
                    std::move(map_mat_id_2_xs),
                    unit_cell_matrices,
                    false,
                    suppress_bcs,
                    verbose)
{
  if (sdm_.GetType() != SpatialDiscretizationType::PIECEWISE_LINEAR_DISCONTINUOUS)
    throw std::logic_error("acceleration::DiffusionMIPSolver can only be used with PWLD.");
}

void
DiffusionMIPSolver::AssembleAand_b_wQpoints(const std::vector<double>& q_vector)
{
  const std::string fname = "acceleration::DiffusionMIPSolver::"
                            "AssembleAand_b_wQpoints";
  if (A_ == nullptr or rhs_ == nullptr or ksp_ == nullptr)
    throw std::logic_error(fname + ": Some or all PETSc elements are null. "
                                   "Check that Initialize has been called.");
  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Starting assembly";

  const size_t num_groups = uk_man_.unknowns.front().num_components;

  VecSet(rhs_, 0.0);

  for (const auto& cell : grid_->local_cells)
  {
    const size_t num_faces = cell.faces.size();
    const auto& cell_mapping = sdm_.GetCellMapping(cell);
    const size_t num_nodes = cell_mapping.GetNumNodes();
    const auto cc_nodes = cell_mapping.GetNodeLocations();
    const auto fe_vol_data = cell_mapping.MakeVolumetricFiniteElementData();

    const auto& xs = mat_id_2_xs_map_.at(cell.block_id);

    DenseMatrix<double> cell_A(num_nodes, num_nodes);
    Vector<double> cell_rhs(num_nodes);
    Vector<PetscInt> cell_idxs(num_nodes);
    // For component/group
    for (size_t g = 0; g < num_groups; ++g)
    {
      cell_A.Set(0.);
      cell_rhs.Set(0.);
      for (size_t i = 0; i < num_nodes; ++i)
        cell_idxs(i) = sdm_.MapDOF(cell, i, uk_man_, 0, g);

      // Get coefficient and nodal src
      const double Dg = xs.Dg[g];
      const double sigr_g = xs.sigR[g];

      std::vector<double> qg(num_nodes, 0.0);
      for (size_t j = 0; j < num_nodes; ++j)
        qg[j] = q_vector[sdm_.MapDOFLocal(cell, j, uk_man_, 0, g)];

      // Assemble continuous terms
      for (size_t i = 0; i < num_nodes; ++i)
      {
        double entry_rhs_i = 0.0; // entry may accumulate over j
        for (size_t j = 0; j < num_nodes; ++j)
        {
          double entry_aij = 0.0;
          for (size_t qp : fe_vol_data.GetQuadraturePointIndices())
          {
            entry_aij += Dg * fe_vol_data.ShapeGrad(i, qp).Dot(fe_vol_data.ShapeGrad(j, qp)) *
                         fe_vol_data.JxW(qp);

            entry_aij += sigr_g * fe_vol_data.ShapeValue(i, qp) * fe_vol_data.ShapeValue(j, qp) *
                         fe_vol_data.JxW(qp);

            if (not source_function_)
              entry_rhs_i += fe_vol_data.ShapeValue(i, qp) * fe_vol_data.ShapeValue(j, qp) *
                             fe_vol_data.JxW(qp) * qg[j];
          } // for qp
          cell_A(i, j) += entry_aij;
        } // for j

        if (source_function_)
        {
          for (size_t qp : fe_vol_data.GetQuadraturePointIndices())
            entry_rhs_i += source_function_(fe_vol_data.QPointXYZ(qp)) *
                           fe_vol_data.ShapeValue(i, qp) * fe_vol_data.JxW(qp);
        }

        cell_rhs(i) += entry_rhs_i;
      } // for i

      // Assemble face terms
      for (size_t f = 0; f < num_faces; ++f)
      {
        const auto& face = cell.faces[f];
        const auto& n_f = face.normal;
        const size_t num_face_nodes = cell_mapping.GetNumFaceNodes(f);
        const auto fe_srf_data = cell_mapping.MakeSurfaceFiniteElementData(f);

        const double hm = HPerpendicular(cell, f);

        if (face.has_neighbor)
        {
          const auto& adj_cell = grid_->cells[face.neighbor_id];
          const auto& adj_cell_mapping = sdm_.GetCellMapping(adj_cell);
          const auto ac_nodes = adj_cell_mapping.GetNodeLocations();
          const size_t acf = MeshContinuum::MapCellFace(cell, adj_cell, f);
          const double hp = HPerpendicular(adj_cell, acf);

          const auto& adj_xs = mat_id_2_xs_map_.at(adj_cell.block_id);
          const double adj_Dg = adj_xs.Dg[g];

          // Compute kappa
          double kappa = 1.0;
          if (cell.GetType() == CellType::SLAB)
            kappa = fmax(options.penalty_factor * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);
          if (cell.GetType() == CellType::POLYGON)
            kappa = fmax(options.penalty_factor * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);
          if (cell.GetType() == CellType::POLYHEDRON)
            kappa = fmax(options.penalty_factor * 2.0 * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);

          DenseMatrix<double> adj_A(num_nodes, num_face_nodes, 0.);
          DenseMatrix<double> adj_AT(num_face_nodes, num_nodes, 0.);
          Vector<PetscInt> adj_idxs(num_face_nodes);
          for (size_t fj = 0; fj < num_face_nodes; ++fj)
          {
            const auto jp =
              MapFaceNodeDisc(cell, adj_cell, cc_nodes, ac_nodes, f, acf, fj); // j-plus
            adj_idxs(fj) = sdm_.MapDOF(adj_cell, jp, uk_man_, 0, g);
          }

          // Assembly penalty terms
          for (size_t fi = 0; fi < num_face_nodes; ++fi)
          {
            const int i = cell_mapping.MapFaceNode(f, fi);

            for (size_t fj = 0; fj < num_face_nodes; ++fj)
            {
              const int jm = cell_mapping.MapFaceNode(f, fj); // j-minus

              double aij = 0.0;
              for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                aij += kappa * fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(jm, qp) *
                       fe_srf_data.JxW(qp);

              cell_A(i, jm) += aij;
              adj_A(i, fj) -= aij;
            } // for fj
          } // for fi

          // Assemble gradient terms
          // For the following comments we use the notation:
          // Dk = 0.5* n dot nabla bk

          // 0.5*D* n dot (b_j^+ - b_j^-)*nabla b_i^-
          for (size_t i = 0; i < num_nodes; ++i)
          {
            for (size_t fj = 0; fj < num_face_nodes; ++fj)
            {
              const int jm = cell_mapping.MapFaceNode(f, fj); // j-minus

              Vector3 vec_aij;
              for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                vec_aij += fe_srf_data.ShapeValue(jm, qp) * fe_srf_data.ShapeGrad(i, qp) *
                           fe_srf_data.JxW(qp);
              const double aij = -0.5 * Dg * n_f.Dot(vec_aij);

              cell_A(i, jm) += aij;
              adj_A(i, fj) -= aij;
            } // for fj
          } // for i

          // 0.5*D* n dot (b_i^+ - b_i^-)*nabla b_j^-
          for (size_t fi = 0; fi < num_face_nodes; ++fi)
          {
            const int im = cell_mapping.MapFaceNode(f, fi); // i-minus

            for (size_t j = 0; j < num_nodes; ++j)
            {
              Vector3 vec_aij;
              for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                vec_aij += fe_srf_data.ShapeValue(im, qp) * fe_srf_data.ShapeGrad(j, qp) *
                           fe_srf_data.JxW(qp);
              const double aij = -0.5 * Dg * n_f.Dot(vec_aij);

              cell_A(im, j) += aij;
              adj_AT(fi, j) -= aij;
            } // for j
          } // for fi

          MatSetValues(A_,
                       num_nodes,
                       cell_idxs.data(),
                       num_face_nodes,
                       adj_idxs.data(),
                       adj_A.data(),
                       ADD_VALUES);

          MatSetValues(A_,
                       num_face_nodes,
                       adj_idxs.data(),
                       num_nodes,
                       cell_idxs.data(),
                       adj_AT.data(),
                       ADD_VALUES);

        } // internal face
        else
        {
          BoundaryCondition bc;
          if (bcs_.count(face.neighbor_id) > 0)
            bc = bcs_.at(face.neighbor_id);

          if (bc.type == BCType::DIRICHLET)
          {
            const double bc_value = bc.values[0];

            // Compute kappa
            double kappa = 1.0;
            if (cell.GetType() == CellType::SLAB)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYGON)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYHEDRON)
              kappa = fmax(options.penalty_factor * 2.0 * Dg / hm, 0.25);

            // Assembly penalty terms
            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              for (size_t fj = 0; fj < num_face_nodes; ++fj)
              {
                const int jm = cell_mapping.MapFaceNode(f, fj);

                double aij = 0.0;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  aij += kappa * fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(jm, qp) *
                         fe_srf_data.JxW(qp);
                double aij_bc_value = aij * bc_value;

                if (ref_solution_function_)
                {
                  aij_bc_value = 0.0;
                  for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                    aij_bc_value += kappa * ref_solution_function_(fe_srf_data.QPointXYZ(qp)) *
                                    fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(jm, qp) *
                                    fe_srf_data.JxW(qp);
                }

                cell_A(i, jm) += aij;
                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for fi

            // Assemble gradient terms
            // For the following comments we use the notation:
            // Dk = n dot nabla bk

            // D* n dot (b_j^+ - b_j^-)*nabla b_i^-
            for (size_t i = 0; i < num_nodes; ++i)
            {
              for (size_t j = 0; j < num_nodes; ++j)
              {
                Vector3 vec_aij;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  vec_aij += fe_srf_data.ShapeValue(j, qp) * fe_srf_data.ShapeGrad(i, qp) *
                               fe_srf_data.JxW(qp) +
                             fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeGrad(j, qp) *
                               fe_srf_data.JxW(qp);
                const double aij = -Dg * n_f.Dot(vec_aij);

                double aij_bc_value = aij * bc_value;

                if (ref_solution_function_)
                {
                  Vector3 vec_aij_mms;
                  for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                    vec_aij_mms += ref_solution_function_(fe_srf_data.QPointXYZ(qp)) *
                                   (fe_srf_data.ShapeValue(j, qp) * fe_srf_data.ShapeGrad(i, qp) *
                                      fe_srf_data.JxW(qp) +
                                    fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeGrad(j, qp) *
                                      fe_srf_data.JxW(qp));
                  aij_bc_value = -Dg * n_f.Dot(vec_aij_mms);
                }

                cell_A(i, j) += aij;
                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for i
          } // Dirichlet BC
          else if (bc.type == BCType::ROBIN)
          {
            const double aval = bc.values[0];
            const double bval = bc.values[1];
            const double fval = bc.values[2];

            if (std::fabs(bval) < 1.0e-12)
              continue; // a and f assumed zero

            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              if (std::fabs(aval) >= 1.0e-12)
              {
                for (size_t fj = 0; fj < num_face_nodes; ++fj)
                {
                  const int j = cell_mapping.MapFaceNode(f, fj);

                  double aij = 0.0;
                  for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                    aij += fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(j, qp) *
                           fe_srf_data.JxW(qp);
                  aij *= (aval / bval);

                  cell_A(i, j) += aij;
                } // for fj
              } // if a nonzero

              if (std::fabs(fval) >= 1.0e-12)
              {
                double rhs_val = 0.0;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  rhs_val += fe_srf_data.ShapeValue(i, qp) * fe_srf_data.JxW(qp);
                rhs_val *= (fval / bval);

                cell_rhs(i) += rhs_val;
              } // if f nonzero
            } // for fi
          } // Robin BC
        } // boundary face
      } // for face

      MatSetValues(
        A_, num_nodes, cell_idxs.data(), num_nodes, cell_idxs.data(), cell_A.data(), ADD_VALUES);
      VecSetValues(rhs_, num_nodes, cell_idxs.data(), cell_rhs.data(), ADD_VALUES);
    } // for g
  } // for cell

  MatAssemblyBegin(A_, MAT_FINAL_ASSEMBLY);
  MatAssemblyEnd(A_, MAT_FINAL_ASSEMBLY);
  VecAssemblyBegin(rhs_);
  VecAssemblyEnd(rhs_);

  if (options.perform_symmetry_check)
  {
    PetscBool symmetry = PETSC_FALSE;
    MatIsSymmetric(A_, 1.0e-6, &symmetry);
    if (symmetry == PETSC_FALSE)
      throw std::logic_error(fname + ":Symmetry check failed");
  }

  KSPSetOperators(ksp_, A_, A_);

  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Assembly completed";

  PC pc;
  KSPGetPC(ksp_, &pc);
  PCSetUp(pc);

  KSPSetUp(ksp_);
}

void
DiffusionMIPSolver::Assemble_b_wQpoints(const std::vector<double>& q_vector)
{
  const std::string fname = "acceleration::DiffusionMIPSolver::"
                            "AssembleAand_b_wQpoints";
  if (A_ == nullptr or rhs_ == nullptr or ksp_ == nullptr)
    throw std::logic_error(fname + ": Some or all PETSc elements are null. "
                                   "Check that Initialize has been called.");
  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Starting assembly";

  VecSet(rhs_, 0.0);

  for (const auto& cell : grid_->local_cells)
  {
    const size_t num_faces = cell.faces.size();
    const auto& cell_mapping = sdm_.GetCellMapping(cell);
    const size_t num_nodes = cell_mapping.GetNumNodes();
    const auto fe_vol_data = cell_mapping.MakeVolumetricFiniteElementData();
    const size_t num_groups = uk_man_.unknowns.front().num_components;

    const auto& xs = mat_id_2_xs_map_.at(cell.block_id);

    Vector<double> cell_rhs(num_nodes);
    Vector<PetscInt> cell_idxs(num_nodes);
    // For component/group
    for (size_t g = 0; g < num_groups; ++g)
    {
      cell_rhs.Set(0.);
      for (size_t i = 0; i < num_nodes; ++i)
        cell_idxs(i) = sdm_.MapDOF(cell, i, uk_man_, 0, g);

      // Get coefficient and nodal src
      const double Dg = xs.Dg[g];

      std::vector<double> qg(num_nodes, 0.0);
      for (size_t j = 0; j < num_nodes; ++j)
        qg[j] = q_vector[sdm_.MapDOFLocal(cell, j, uk_man_, 0, g)];

      // Assemble continuous terms
      for (size_t i = 0; i < num_nodes; ++i)
      {
        double entry_rhs_i = 0.0; // entry may accumulate over j
        if (not source_function_)
          for (size_t j = 0; j < num_nodes; ++j)
          {
            for (size_t qp : fe_vol_data.GetQuadraturePointIndices())
            {
              entry_rhs_i += fe_vol_data.ShapeValue(i, qp) * fe_vol_data.ShapeValue(j, qp) *
                             fe_vol_data.JxW(qp) * qg[j];
            } // for qp
          } // for j
        else
        {
          for (size_t qp : fe_vol_data.GetQuadraturePointIndices())
            entry_rhs_i += source_function_(fe_vol_data.QPointXYZ(qp)) *
                           fe_vol_data.ShapeValue(i, qp) * fe_vol_data.JxW(qp);
        }

        cell_rhs(i) += entry_rhs_i;
      } // for i

      // Assemble face terms
      for (size_t f = 0; f < num_faces; ++f)
      {
        const auto& face = cell.faces[f];
        const auto& n_f = face.normal;
        const size_t num_face_nodes = cell_mapping.GetNumFaceNodes(f);
        const auto fe_srf_data = cell_mapping.MakeSurfaceFiniteElementData(f);

        const double hm = HPerpendicular(cell, f);

        if (not face.has_neighbor and not suppress_bcs_)
        {
          BoundaryCondition bc;
          if (bcs_.count(face.neighbor_id) > 0)
            bc = bcs_.at(face.neighbor_id);

          if (bc.type == BCType::DIRICHLET)
          {
            const double bc_value = bc.values[0];

            // Compute kappa
            double kappa = 1.0;
            if (cell.GetType() == CellType::SLAB)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYGON)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYHEDRON)
              kappa = fmax(options.penalty_factor * 2.0 * Dg / hm, 0.25);

            // Assembly penalty terms
            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              for (size_t fj = 0; fj < num_face_nodes; ++fj)
              {
                const int jm = cell_mapping.MapFaceNode(f, fj);

                double aij = 0.0;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  aij += kappa * fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(jm, qp) *
                         fe_srf_data.JxW(qp);
                double aij_bc_value = aij * bc_value;

                if (ref_solution_function_)
                {
                  aij_bc_value = 0.0;
                  for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                    aij_bc_value += kappa * source_function_(fe_srf_data.QPointXYZ(qp)) *
                                    fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeValue(jm, qp) *
                                    fe_srf_data.JxW(qp);
                }

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for fi

            // Assemble gradient terms
            // For the following comments we use the notation:
            // Dk = 0.5* n dot nabla bk

            // 0.5*D* n dot (b_j^+ - b_j^-)*nabla b_i^-
            for (size_t i = 0; i < num_nodes; ++i)
            {
              for (size_t j = 0; j < num_nodes; ++j)
              {
                Vector3 vec_aij;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  vec_aij += fe_srf_data.ShapeValue(j, qp) * fe_srf_data.ShapeGrad(i, qp) *
                               fe_srf_data.JxW(qp) +
                             fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeGrad(j, qp) *
                               fe_srf_data.JxW(qp);
                const double aij = -Dg * n_f.Dot(vec_aij);

                double aij_bc_value = aij * bc_value;

                if (ref_solution_function_)
                {
                  Vector3 vec_aij_mms;
                  for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                    vec_aij_mms += ref_solution_function_(fe_srf_data.QPointXYZ(qp)) *
                                   (fe_srf_data.ShapeValue(j, qp) * fe_srf_data.ShapeGrad(i, qp) *
                                      fe_srf_data.JxW(qp) +
                                    fe_srf_data.ShapeValue(i, qp) * fe_srf_data.ShapeGrad(j, qp) *
                                      fe_srf_data.JxW(qp));
                  aij_bc_value = -Dg * n_f.Dot(vec_aij_mms);
                }

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for i
          } // Dirichlet BC
          else if (bc.type == BCType::ROBIN)
          {
            const double bval = bc.values[1];
            const double fval = bc.values[2];

            if (std::fabs(bval) < 1.0e-12)
              continue; // a and f assumed zero

            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              if (std::fabs(fval) >= 1.0e-12)
              {
                double rhs_val = 0.0;
                for (size_t qp : fe_srf_data.GetQuadraturePointIndices())
                  rhs_val += fe_srf_data.ShapeValue(i, qp) * fe_srf_data.JxW(qp);
                rhs_val *= (fval / bval);

                cell_rhs(i) += rhs_val;
              } // if f nonzero
            } // for fi
          } // Robin BC
        } // boundary face
      } // for face
      VecSetValues(rhs_, num_nodes, cell_idxs.data(), cell_rhs.data(), ADD_VALUES);
    } // for g
  } // for cell

  VecAssemblyBegin(rhs_);
  VecAssemblyEnd(rhs_);

  KSPSetOperators(ksp_, A_, A_);

  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Assembly completed";

  PC pc;
  KSPGetPC(ksp_, &pc);
  PCSetUp(pc);

  KSPSetUp(ksp_);
}

void
DiffusionMIPSolver::AssembleAand_b(const std::vector<double>& q_vector)
{
  const std::string fname = "acceleration::DiffusionMIPSolver::"
                            "AssembleAand_b";
  if (A_ == nullptr or rhs_ == nullptr or ksp_ == nullptr)
    throw std::logic_error(fname + ": Some or all PETSc elements are null. "
                                   "Check that Initialize has been called.");
  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Starting assembly";

  const size_t num_groups = uk_man_.unknowns.front().num_components;

  VecSet(rhs_, 0.0);
  for (const auto& cell : grid_->local_cells)
  {
    const size_t num_faces = cell.faces.size();
    const auto& cell_mapping = sdm_.GetCellMapping(cell);
    const size_t num_nodes = cell_mapping.GetNumNodes();
    const auto cc_nodes = cell_mapping.GetNodeLocations();
    const auto& unit_cell_matrices = unit_cell_matrices_[cell.local_id];

    const auto& intV_gradshapeI_gradshapeJ = unit_cell_matrices.intV_gradshapeI_gradshapeJ;
    const auto& intV_shapeI_shapeJ = unit_cell_matrices.intV_shapeI_shapeJ;

    const auto& xs = mat_id_2_xs_map_.at(cell.block_id);

    DenseMatrix<double> cell_A(num_nodes, num_nodes);
    Vector<double> cell_rhs(num_nodes);
    Vector<PetscInt> cell_idxs(num_nodes);
    for (size_t g = 0; g < num_groups; ++g)
    {
      cell_A.Set(0.);
      cell_rhs.Set(0.);
      for (size_t i = 0; i < num_nodes; ++i)
        cell_idxs(i) = sdm_.MapDOF(cell, i, uk_man_, 0, g);

      // Get coefficient and nodal src
      const double Dg = xs.Dg[g];
      const double sigr_g = xs.sigR[g];

      std::vector<double> qg(num_nodes, 0.0);
      for (size_t j = 0; j < num_nodes; ++j)
        qg[j] = q_vector[sdm_.MapDOFLocal(cell, j, uk_man_, 0, g)];

      // Assemble continuous terms
      for (size_t i = 0; i < num_nodes; ++i)
      {
        double entry_rhs_i = 0.0;
        for (size_t j = 0; j < num_nodes; ++j)
        {
          const double entry_aij =
            Dg * intV_gradshapeI_gradshapeJ(i, j) + sigr_g * intV_shapeI_shapeJ(i, j);

          entry_rhs_i += intV_shapeI_shapeJ(i, j) * qg[j];

          cell_A(i, j) += entry_aij;
        } // for j

        cell_rhs(i) += entry_rhs_i;
      } // for i

      // Assemble face terms
      for (size_t f = 0; f < num_faces; ++f)
      {
        const auto& face = cell.faces[f];
        const auto& n_f = face.normal;
        const size_t num_face_nodes = cell_mapping.GetNumFaceNodes(f);

        const auto& intS_shapeI_shapeJ = unit_cell_matrices.intS_shapeI_shapeJ[f];
        const auto& intS_shapeI_gradshapeJ = unit_cell_matrices.intS_shapeI_gradshapeJ[f];
        const auto& intS_shapeI = unit_cell_matrices.intS_shapeI[f];

        const double hm = HPerpendicular(cell, f);

        if (face.has_neighbor)
        {
          const auto& adj_cell = grid_->cells[face.neighbor_id];
          const auto& adj_cell_mapping = sdm_.GetCellMapping(adj_cell);
          const auto ac_nodes = adj_cell_mapping.GetNodeLocations();
          const size_t acf = MeshContinuum::MapCellFace(cell, adj_cell, f);
          const double hp = HPerpendicular(adj_cell, acf);

          const auto& adj_xs = mat_id_2_xs_map_.at(adj_cell.block_id);
          const double adj_Dg = adj_xs.Dg[g];

          // Compute kappa
          double kappa = 1.0;
          if (cell.GetType() == CellType::SLAB)
            kappa = fmax(options.penalty_factor * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);
          if (cell.GetType() == CellType::POLYGON)
            kappa = fmax(options.penalty_factor * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);
          if (cell.GetType() == CellType::POLYHEDRON)
            kappa = fmax(options.penalty_factor * 2.0 * (adj_Dg / hp + Dg / hm) * 0.5, 0.25);

          DenseMatrix<double> adj_A(num_nodes, num_face_nodes, 0.);
          DenseMatrix<double> adj_AT(num_face_nodes, num_nodes, 0.);
          Vector<PetscInt> adj_idxs(num_face_nodes);
          for (size_t fj = 0; fj < num_face_nodes; ++fj)
          {
            const auto jp =
              MapFaceNodeDisc(cell, adj_cell, cc_nodes, ac_nodes, f, acf, fj); // j-plus
            adj_idxs(fj) = sdm_.MapDOF(adj_cell, jp, uk_man_, 0, g);
          }

          // Assembly penalty terms
          for (size_t fi = 0; fi < num_face_nodes; ++fi)
          {
            const int i = cell_mapping.MapFaceNode(f, fi);

            for (size_t fj = 0; fj < num_face_nodes; ++fj)
            {
              const int jm = cell_mapping.MapFaceNode(f, fj); // j-minus

              const double aij = kappa * intS_shapeI_shapeJ(i, jm);

              cell_A(i, jm) += aij;
              adj_A(i, fj) -= aij;
            } // for fj
          } // for fi

          // Assemble gradient terms
          // For the following comments we use the notation:
          // Dk = 0.5* n dot nabla bk

          // 0.5*D* n dot (b_j^+ - b_j^-)*nabla b_i^-
          for (size_t i = 0; i < num_nodes; ++i)
          {
            for (size_t fj = 0; fj < num_face_nodes; ++fj)
            {
              const int jm = cell_mapping.MapFaceNode(f, fj); // j-minus

              const double aij = -0.5 * Dg * n_f.Dot(intS_shapeI_gradshapeJ(jm, i));

              cell_A(i, jm) += aij;
              adj_A(i, fj) -= aij;
            } // for fj
          } // for i

          // 0.5*D* n dot (b_i^+ - b_i^-)*nabla b_j^-
          for (size_t fi = 0; fi < num_face_nodes; ++fi)
          {
            const int im = cell_mapping.MapFaceNode(f, fi); // i-minus

            for (size_t j = 0; j < num_nodes; ++j)
            {
              const double aij = -0.5 * Dg * n_f.Dot(intS_shapeI_gradshapeJ(im, j));

              cell_A(im, j) += aij;
              adj_AT(fi, j) -= aij;
            } // for j
          } // for fi

          MatSetValues(A_,
                       num_nodes,
                       cell_idxs.data(),
                       num_face_nodes,
                       adj_idxs.data(),
                       adj_A.data(),
                       ADD_VALUES);

          MatSetValues(A_,
                       num_face_nodes,
                       adj_idxs.data(),
                       num_nodes,
                       cell_idxs.data(),
                       adj_AT.data(),
                       ADD_VALUES);

        } // internal face
        else
        {
          BoundaryCondition bc;
          if (bcs_.count(face.neighbor_id) > 0)
            bc = bcs_.at(face.neighbor_id);

          if (bc.type == BCType::DIRICHLET)
          {
            const double bc_value = bc.values[0];

            // Compute kappa
            double kappa = 1.0;
            if (cell.GetType() == CellType::SLAB)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYGON)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYHEDRON)
              kappa = fmax(options.penalty_factor * 2.0 * Dg / hm, 0.25);

            // Assembly penalty terms
            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              for (size_t fj = 0; fj < num_face_nodes; ++fj)
              {
                const int jm = cell_mapping.MapFaceNode(f, fj);

                const double aij = kappa * intS_shapeI_shapeJ(i, jm);
                const double aij_bc_value = aij * bc_value;

                cell_A(i, jm) += aij;
                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for fi

            // Assemble gradient terms
            // For the following comments we use the notation:
            // Dk = n dot nabla bk

            // D* n dot (b_j^+ - b_j^-)*nabla b_i^-
            for (size_t i = 0; i < num_nodes; ++i)
            {
              for (size_t j = 0; j < num_nodes; ++j)
              {
                const double aij =
                  -Dg * n_f.Dot(intS_shapeI_gradshapeJ(j, i) + intS_shapeI_gradshapeJ(i, j));
                const double aij_bc_value = aij * bc_value;

                cell_A(i, j) += aij;
                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for i
          } // Dirichlet BC
          else if (bc.type == BCType::ROBIN)
          {
            const double aval = bc.values[0];
            const double bval = bc.values[1];
            const double fval = bc.values[2];

            if (std::fabs(bval) < 1.0e-12)
              continue; // a and f assumed zero

            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              if (std::fabs(aval) >= 1.0e-12)
              {
                for (size_t fj = 0; fj < num_face_nodes; ++fj)
                {
                  const int j = cell_mapping.MapFaceNode(f, fj);

                  const double aij = (aval / bval) * intS_shapeI_shapeJ(i, j);

                  cell_A(i, j) += aij;
                } // for fj
              } // if a nonzero

              if (std::fabs(fval) >= 1.0e-12)
              {
                const double rhs_val = (fval / bval) * intS_shapeI(i);

                cell_rhs(i) += rhs_val;
              } // if f nonzero
            } // for fi
          } // Robin BC
        } // boundary face
      } // for face

      MatSetValues(
        A_, num_nodes, cell_idxs.data(), num_nodes, cell_idxs.data(), cell_A.data(), ADD_VALUES);
      VecSetValues(rhs_, num_nodes, cell_idxs.data(), cell_rhs.data(), ADD_VALUES);
    } // for g
  } // for cell

  MatAssemblyBegin(A_, MAT_FINAL_ASSEMBLY);
  MatAssemblyEnd(A_, MAT_FINAL_ASSEMBLY);
  VecAssemblyBegin(rhs_);
  VecAssemblyEnd(rhs_);

  if (options.verbose)
  {
    MatInfo info;
    MatGetInfo(A_, MAT_GLOBAL_SUM, &info);

    log.Log() << "Number of mallocs used = " << info.mallocs
              << "\nNumber of non-zeros allocated = " << info.nz_allocated
              << "\nNumber of non-zeros used = " << info.nz_used
              << "\nNumber of unneeded non-zeros = " << info.nz_unneeded;
  }

  if (options.perform_symmetry_check)
  {
    PetscBool symmetry = PETSC_FALSE;
    MatIsSymmetric(A_, 1.0e-6, &symmetry);
    if (symmetry == PETSC_FALSE)
      throw std::logic_error(fname + ":Symmetry check failed");
  }

  KSPSetOperators(ksp_, A_, A_);

  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Assembly completed";

  PC pc;
  KSPGetPC(ksp_, &pc);
  PCSetUp(pc);

  KSPSetUp(ksp_);
}

void
DiffusionMIPSolver::Assemble_b(const std::vector<double>& q_vector)
{
  const std::string fname = "acceleration::DiffusionMIPSolver::"
                            "Assemble_b";
  if (A_ == nullptr or rhs_ == nullptr or ksp_ == nullptr)
    throw std::logic_error(fname + ": Some or all PETSc elements are null. "
                                   "Check that Initialize has been called.");
  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Starting assembly";

  const size_t num_groups = uk_man_.unknowns.front().num_components;

  VecSet(rhs_, 0.0);
  for (const auto& cell : grid_->local_cells)
  {
    const size_t num_faces = cell.faces.size();
    const auto& cell_mapping = sdm_.GetCellMapping(cell);
    const size_t num_nodes = cell_mapping.GetNumNodes();
    const auto cc_nodes = cell_mapping.GetNodeLocations();
    const auto& unit_cell_matrices = unit_cell_matrices_[cell.local_id];

    const auto& intV_shapeI_shapeJ = unit_cell_matrices.intV_shapeI_shapeJ;

    const auto& xs = mat_id_2_xs_map_.at(cell.block_id);

    Vector<double> cell_rhs(num_nodes);
    Vector<PetscInt> cell_idxs(num_nodes);
    for (size_t g = 0; g < num_groups; ++g)
    {
      cell_rhs.Set(0.);
      for (size_t i = 0; i < num_nodes; ++i)
        cell_idxs(i) = sdm_.MapDOF(cell, i, uk_man_, 0, g);

      // Get coefficient and nodal src
      const double Dg = xs.Dg[g];

      std::vector<double> qg(num_nodes, 0.0);
      for (size_t j = 0; j < num_nodes; ++j)
        qg[j] = q_vector[sdm_.MapDOFLocal(cell, j, uk_man_, 0, g)];

      // Assemble continuous terms
      for (size_t i = 0; i < num_nodes; ++i)
      {
        double entry_rhs_i = 0.0;
        for (size_t j = 0; j < num_nodes; ++j)
          entry_rhs_i += intV_shapeI_shapeJ(i, j) * qg[j];

        cell_rhs(i) += entry_rhs_i;
      } // for i

      // Assemble face terms
      for (size_t f = 0; f < num_faces; ++f)
      {
        const auto& face = cell.faces[f];
        const auto& n_f = face.normal;
        const size_t num_face_nodes = cell_mapping.GetNumFaceNodes(f);

        const auto& intS_shapeI_shapeJ = unit_cell_matrices.intS_shapeI_shapeJ[f];
        const auto& intS_shapeI_gradshapeJ = unit_cell_matrices.intS_shapeI_gradshapeJ[f];
        const auto& intS_shapeI = unit_cell_matrices.intS_shapeI[f];

        const double hm = HPerpendicular(cell, f);

        if (not face.has_neighbor and not suppress_bcs_)
        {
          BoundaryCondition bc;
          if (bcs_.count(face.neighbor_id) > 0)
            bc = bcs_.at(face.neighbor_id);

          if (bc.type == BCType::DIRICHLET)
          {
            const double bc_value = bc.values[0];

            // Compute kappa
            double kappa = 1.0;
            if (cell.GetType() == CellType::SLAB)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYGON)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYHEDRON)
              kappa = fmax(options.penalty_factor * 2.0 * Dg / hm, 0.25);

            // Assembly penalty terms
            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              for (size_t fj = 0; fj < num_face_nodes; ++fj)
              {
                const int jm = cell_mapping.MapFaceNode(f, fj);

                const double aij = kappa * intS_shapeI_shapeJ(i, jm);
                const double aij_bc_value = aij * bc_value;

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for fi

            // Assemble gradient terms
            // For the following comments we use the notation:
            // Dk = n dot nabla bk

            // D* n dot (b_j^+ - b_j^-)*nabla b_i^-
            for (size_t i = 0; i < num_nodes; ++i)
            {
              for (size_t j = 0; j < num_nodes; ++j)
              {
                const double aij =
                  -Dg * n_f.Dot(intS_shapeI_gradshapeJ(j, i) + intS_shapeI_gradshapeJ(i, j));
                const double aij_bc_value = aij * bc_value;

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for i
          } // Dirichlet BC
          else if (bc.type == BCType::ROBIN)
          {
            const double bval = bc.values[1];
            const double fval = bc.values[2];

            if (std::fabs(bval) < 1.0e-12)
              continue; // a and f assumed zero

            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              if (std::fabs(fval) >= 1.0e-12)
              {
                const double rhs_val = (fval / bval) * intS_shapeI(i);

                cell_rhs(i) += rhs_val;
              } // if f nonzero
            } // for fi
          } // Robin BC
        } // boundary face
      } // for face

      VecSetValues(rhs_, num_nodes, cell_idxs.data(), cell_rhs.data(), ADD_VALUES);
    } // for g
  } // for cell

  VecAssemblyBegin(rhs_);
  VecAssemblyEnd(rhs_);

  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Assembly completed";
}

void
DiffusionMIPSolver::Assemble_b(Vec petsc_q_vector)
{
  const std::string fname = "acceleration::DiffusionMIPSolver::"
                            "Assemble_b";
  if (A_ == nullptr or rhs_ == nullptr or ksp_ == nullptr)
    throw std::logic_error(fname + ": Some or all PETSc elements are null. "
                                   "Check that Initialize has been called.");
  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Starting assembly";

  const size_t num_groups = uk_man_.unknowns.front().num_components;

  const double* q_vector;
  VecGetArrayRead(petsc_q_vector, &q_vector);

  VecSet(rhs_, 0.0);
  for (const auto& cell : grid_->local_cells)
  {
    const size_t num_faces = cell.faces.size();
    const auto& cell_mapping = sdm_.GetCellMapping(cell);
    const size_t num_nodes = cell_mapping.GetNumNodes();
    const auto cc_nodes = cell_mapping.GetNodeLocations();
    const auto& unit_cell_matrices = unit_cell_matrices_[cell.local_id];

    const auto& intV_shapeI_shapeJ = unit_cell_matrices.intV_shapeI_shapeJ;

    const auto& xs = mat_id_2_xs_map_.at(cell.block_id);

    Vector<double> cell_rhs(num_nodes);
    Vector<PetscInt> cell_idxs(num_nodes);
    for (size_t g = 0; g < num_groups; ++g)
    {
      cell_rhs.Set(0.);
      for (size_t i = 0; i < num_nodes; ++i)
        cell_idxs(i) = sdm_.MapDOF(cell, i, uk_man_, 0, g);

      // Get coefficient and nodal src
      const double Dg = xs.Dg[g];

      std::vector<double> qg(num_nodes, 0.0);
      for (size_t j = 0; j < num_nodes; ++j)
        qg[j] = q_vector[sdm_.MapDOFLocal(cell, j, uk_man_, 0, g)];

      // Assemble continuous terms
      for (size_t i = 0; i < num_nodes; ++i)
      {
        double entry_rhs_i = 0.0;
        for (size_t j = 0; j < num_nodes; ++j)
          entry_rhs_i += intV_shapeI_shapeJ(i, j) * qg[j];

        cell_rhs(i) += entry_rhs_i;
      } // for i

      // Assemble face terms
      for (size_t f = 0; f < num_faces; ++f)
      {
        const auto& face = cell.faces[f];
        const auto& n_f = face.normal;
        const size_t num_face_nodes = cell_mapping.GetNumFaceNodes(f);

        const auto& intS_shapeI_shapeJ = unit_cell_matrices.intS_shapeI_shapeJ[f];
        const auto& intS_shapeI_gradshapeJ = unit_cell_matrices.intS_shapeI_gradshapeJ[f];
        const auto& intS_shapeI = unit_cell_matrices.intS_shapeI[f];

        const double hm = HPerpendicular(cell, f);

        if (not face.has_neighbor and not suppress_bcs_)
        {
          BoundaryCondition bc;
          if (bcs_.count(face.neighbor_id) > 0)
            bc = bcs_.at(face.neighbor_id);

          if (bc.type == BCType::DIRICHLET)
          {
            const double bc_value = bc.values[0];

            // Compute kappa
            double kappa = 1.0;
            if (cell.GetType() == CellType::SLAB)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYGON)
              kappa = fmax(options.penalty_factor * Dg / hm, 0.25);
            if (cell.GetType() == CellType::POLYHEDRON)
              kappa = fmax(options.penalty_factor * 2.0 * Dg / hm, 0.25);

            // Assembly penalty terms
            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              for (size_t fj = 0; fj < num_face_nodes; ++fj)
              {
                const int jm = cell_mapping.MapFaceNode(f, fj);

                const double aij = kappa * intS_shapeI_shapeJ(i, jm);
                const double aij_bc_value = aij * bc_value;

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for fi

            // Assemble gradient terms
            // For the following comments we use the notation:
            // Dk = n dot nabla bk

            // D* n dot (b_j^+ - b_j^-)*nabla b_i^-
            for (size_t i = 0; i < num_nodes; ++i)
            {
              for (size_t j = 0; j < num_nodes; ++j)
              {
                const double aij =
                  -Dg * n_f.Dot(intS_shapeI_gradshapeJ(j, i) + intS_shapeI_gradshapeJ(i, j));
                const double aij_bc_value = aij * bc_value;

                cell_rhs(i) += aij_bc_value;
              } // for fj
            } // for i
          } // Dirichlet BC
          else if (bc.type == BCType::ROBIN)
          {
            const double bval = bc.values[1];
            const double fval = bc.values[2];

            if (std::fabs(bval) < 1.0e-12)
              continue; // a and f assumed zero

            for (size_t fi = 0; fi < num_face_nodes; ++fi)
            {
              const int i = cell_mapping.MapFaceNode(f, fi);

              if (std::fabs(fval) >= 1.0e-12)
              {
                const double rhs_val = (fval / bval) * intS_shapeI(i);

                cell_rhs(i) += rhs_val;
              } // if f nonzero
            } // for fi
          } // Robin BC
        } // boundary face
      } // for face
      VecSetValues(rhs_, num_nodes, cell_idxs.data(), cell_rhs.data(), ADD_VALUES);
    } // for g
  } // for cell

  VecRestoreArrayRead(petsc_q_vector, &q_vector);

  VecAssemblyBegin(rhs_);
  VecAssemblyEnd(rhs_);

  if (options.verbose)
    log.Log() << program_timer.GetTimeString() << " Assembly completed";
}

double
DiffusionMIPSolver::HPerpendicular(const Cell& cell, unsigned int f)
{
  const auto& cell_mapping = sdm_.GetCellMapping(cell);
  double hp;

  const auto num_faces = cell.faces.size();
  const auto num_vertices = cell.vertex_ids.size();

  const auto volume = cell.volume;
  const auto face_area = cell.faces.at(f).area;

  /**Lambda to compute surface area.*/
  auto ComputeSurfaceArea = [&cell, &num_faces]()
  {
    double surface_area = 0.0;
    for (size_t fr = 0; fr < num_faces; ++fr)
      surface_area += cell.faces[fr].area;

    return surface_area;
  };

  if (cell.GetType() == CellType::SLAB)
  {
    hp = volume / 2.0;
  }
  else if (cell.GetType() == CellType::POLYGON)
  {
    if (num_faces == 3)
      hp = 2.0 * volume / face_area;
    else if (num_faces == 4)
      hp = volume / face_area;
    else // Nv > 4
    {
      const auto surface_area = ComputeSurfaceArea();

      if (num_faces % 2 == 0)
        hp = 4.0 * volume / surface_area;
      else
      {
        hp = 2.0 * volume / surface_area;
        hp +=
          sqrt(2.0 * volume /
               (static_cast<double>(num_faces) * sin(2.0 * M_PI / static_cast<double>(num_faces))));
      }
    }
  }
  else if (cell.GetType() == CellType::POLYHEDRON)
  {
    const auto surface_area = ComputeSurfaceArea();

    if (num_faces == 4) // Tet
      hp = 3 * volume / surface_area;
    else if (num_faces == 6 and num_vertices == 8) // Hex
      hp = volume / surface_area;
    else // Polyhedron
      hp = 6 * volume / surface_area;
  } // Polyhedron
  else
    throw std::logic_error("acceleration::DiffusionMIPSolver::HPerpendicular: "
                           "Unsupported cell type in call to HPerpendicular");

  return hp;
}

int
DiffusionMIPSolver::MapFaceNodeDisc(const Cell& cur_cell,
                                    const Cell& adj_cell,
                                    const std::vector<Vector3>& cc_node_locs,
                                    const std::vector<Vector3>& ac_node_locs,
                                    size_t ccf,
                                    size_t acf,
                                    size_t ccfi,
                                    double epsilon)
{
  const auto& cur_cell_mapping = sdm_.GetCellMapping(cur_cell);
  const auto& adj_cell_mapping = sdm_.GetCellMapping(adj_cell);

  const int i = cur_cell_mapping.MapFaceNode(ccf, ccfi);
  const auto& node_i_loc = cc_node_locs[i];

  const size_t adj_face_num_nodes = adj_cell_mapping.GetNumFaceNodes(acf);

  for (size_t fj = 0; fj < adj_face_num_nodes; ++fj)
  {
    const int j = adj_cell_mapping.MapFaceNode(acf, fj);
    if ((node_i_loc - ac_node_locs[j]).NormSquare() < epsilon)
      return j;
  }

  throw std::logic_error("acceleration::DiffusionMIPSolver::MapFaceNodeDisc: Mapping failure.");
}

} // namespace opensn

Open-Sn / opensn / 18300593117

Source File Press 'n' to go to next uncovered line, 'b' for previous

Source File
Press 'n' to go to next uncovered line, 'b' for previous