lbsmip_TGDSA_preconditioner.cc

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#include "lbs_shell_operations.h"
 
#include "A_LBSSolver/lbs_solver.h"
#include "A_LBSSolver/Acceleration/diffusion_mip.h"
#include "LinearBoltzmannSolvers/A_LBSSolver/IterativeMethods/wgs_context.h"
 
//###################################################################
/**Applies TGDSA to the given input vector.*/
int lbs::MIP_TGDSA_PreConditionerMult(PC pc, Vec phi_input, Vec pc_output)
{
  void* context;
  PCShellGetContext(pc,&context);
 
  auto gs_context_ptr = (lbs::WGSContext<Mat,Vec,KSP>*)(context);
 
  //Shorten some names
  lbs::LBSSolver& solver = gs_context_ptr->lbs_solver_;
  LBSGroupset& groupset  = gs_context_ptr->groupset_;
 
  //============================================= Copy PETSc vector to STL
  auto& phi_delta = gs_context_ptr->lbs_solver_.PhiNewLocal();
  solver.SetPrimarySTLvectorFromGSPETScVec(groupset, phi_input,
                                           PhiSTLOption::PHI_NEW);
 
  //============================================= Apply TGDSA
  if (groupset.apply_tgdsa_)
  {
    std::vector<double> delta_phi_local;
    solver.AssembleTGDSADeltaPhiVector(groupset, phi_delta, delta_phi_local);
    groupset.tgdsa_solver_->Assemble_b(delta_phi_local);
    groupset.tgdsa_solver_->Solve(delta_phi_local);
    solver.DisAssembleTGDSADeltaPhiVector(groupset, delta_phi_local, phi_delta);
  }
 
  //============================================= Copy STL vector to PETSc Vec
  solver.SetGSPETScVecFromPrimarySTLvector(groupset,
                                           pc_output,
                                           PhiSTLOption::PHI_NEW);
 
  return 0;
}