PrecondA.cpp

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#include <Matrice_Morse_Sym.h>
#include <Matrice_Bloc_Sym.h>
#include <TRUSTTab_parts.h>
#include <PrecondA.h>
#include <Motcle.h>
#include <Param.h>
 
Implemente_instanciable(PrecondA,"ssor_bloc",Precond_base);
// XD ssor_bloc precond_base ssor_bloc INHERITS_BRACE not_set
 
Sortie& PrecondA::printOn(Sortie& s ) const
{
  return s;
}
 
Entree& PrecondA::readOn(Entree& is )
{
  Param param(que_suis_je());
  set_param(param);
  param.lire_avec_accolades_depuis(is);
  return is;
}
 
void PrecondA::set_param(Param& param) const
{
  param.ajouter("precond0",&le_precond_0); // XD attr precond0 precond_base precond0 OPT not_set
  param.ajouter("precond1",&le_precond_1); // XD attr precond1 precond_base precond1 OPT not_set
  param.ajouter("preconda",&le_precond_a); // XD attr preconda precond_base preconda OPT not_set
  param.ajouter("alpha_0",&alpha_0);   // XD attr alpha_0 floattant alpha_0 OPT not_set
  param.ajouter("alpha_1",&alpha_1);   // XD attr alpha_1 floattant alpha_1 OPT not_set
  param.ajouter("alpha_a",&alpha_a);   // XD attr alpha_a floattant alpha_a OPT not_set
}
 
static void prepare_precond(OWN_PTR(Precond_base)& p, const Matrice_Base& m, const DoubleVect& v,
                            Precond_base::Init_Status status)
{
  if (p)
    {
      Precond_base& pp = p.valeur();
      pp.reinit(status);
      pp.prepare(m, v);
    }
}
 
void PrecondA::prepare_(const Matrice_Base& m, const DoubleVect& v)
{
  Init_Status status = get_status();
  const Matrice_Bloc_Sym& matbloc = ref_cast(Matrice_Bloc_Sym, m);
  ConstDoubleTab_parts parts(v);
  prepare_precond(le_precond_0, matbloc.get_bloc(0,0), parts[0], status);
  prepare_precond(le_precond_1, matbloc.get_bloc(1,1), parts[1], status);
  if (parts.size() > 2)
    prepare_precond(le_precond_a, matbloc.get_bloc(2,2), parts[2], status);
  Precond_base::prepare_(m, v);
}
 
/*! @brief Calcule la solution du systeme lineaire: A * solution = b avec la methode de relaxation PrecondA.
 *
 */
int PrecondA::preconditionner_(const Matrice_Base& matrice,
                               const DoubleVect& b,
                               DoubleVect& solution)
{
 
  double pscb = mp_prodscal(b, b);
 
  if(pscb<1.e-24)
    {
      solution=b;
      return 1;
    }
  // On calcule solution = inverse(C)*b avec:
  //   inverse(C) = inverse((1/w D - E)) *(2-w/w D) * inverse((1/wD -E)t)
  //   D :partie diagonale des blocs de la matrice
  //   E :partie triangulaire inferieure des blocs de la matrice
  const Matrice_Bloc_Sym& matbloc=ref_cast(Matrice_Bloc_Sym, matrice);
  if (matbloc.nb_bloc_lignes()<2
      || matbloc.nb_bloc_colonnes()<2
      || matbloc.nb_bloc_lignes()!=matbloc.nb_bloc_colonnes())
    {
      Cerr << "The preconditioning SSOR_BLOC can be used only for symetric block matrixes" << finl;
      Cerr << "containing at least 2*2 blocs. For example, when considering the following VEF discretizations :"<< finl;
      Cerr << "P0+P1 or P0+Pa or P0+P1+Pa." << finl;
      exit();
    }
  int nblocs=matbloc.nb_bloc_lignes();
  const Matrice_Base& A00=matbloc.get_bloc(0,0);
  const Matrice_Base& A01=matbloc.get_bloc(0,1);
  const Matrice_Base& A11=matbloc.get_bloc(1,1);
  const Matrice_Base& A0a=matbloc.get_bloc(0,nblocs-1);
  const Matrice_Base& A1a=matbloc.get_bloc(1,nblocs-1);
  const Matrice_Base& Aaa=matbloc.get_bloc(nblocs-1,nblocs-1);
  DoubleTab_parts parties(solution);
  DoubleVect& X0 = parties[0];
  DoubleVect& X1 = parties[1];
  DoubleVect& Xa = parties[parties.size() - 1];
 
  DoubleVect F(b);
  DoubleTab_parts parties_f(F);
  DoubleVect& Y0 = parties_f[0];
  DoubleVect& Y1 = parties_f[1];
  DoubleVect& Ya = parties_f[parties_f.size() - 1];
 
#ifdef TRACE
  Cerr << finl << "Y0 " << mp_norme_vect(Y0) << finl;
  Cerr << finl << "Y1 " << mp_norme_vect(Y1) << finl;
  if(nblocs == 3)
    Cerr << finl << "Ya " << mp_norme_vect(Ya) << finl;
  matrice.multvect(b, F);
  double psc=mp_prodscal(F,b);
  assert(psc>0);
  double pscF=mp_prodscal(F,F);
  Cout << finl <<"cos(angle) no prec " << psc*psc/(pscF*pscb) << finl;
  Cout << finl <<"(F,b) " << psc << finl;
  Cout << finl <<"(b,b) " << pscb << finl;
  Cout << finl <<"(F,F) " << pscF << finl;
  F.ajoute(-psc/pscb,b,VECT_ALL_ITEMS);
 
  Cout << finl <<"(F0,F0) " << mp_prodscal(Y0,Y0) << finl;
  Cout << finl <<"(F1,F1) " << mp_prodscal(Y1,Y1) << finl;
  if(nblocs == 3)
    Cout << finl <<"(Fa,Fa) " << mp_prodscal(Ya,Ya) << finl;
  F=b;
#endif
 
  // Descente :
 
  le_precond_1->preconditionner(A11,Y1,X1);
  operator_multiply(X1, -alpha_1, VECT_ALL_ITEMS);
  A11.ajouter_multvect(X1, Y1);
  A01.ajouter_multvect(X1, Y0);
  if(nblocs == 3)
    A1a.ajouter_multvectT(X1, Ya);
  operator_multiply(X1, -1, VECT_ALL_ITEMS);
  le_precond_0->preconditionner(A00,Y0,X0);
  operator_multiply(X0, -alpha_0, VECT_ALL_ITEMS);
  A00.ajouter_multvect(X0, Y0);
  A01.ajouter_multvectT(X0, Y1);
  if(nblocs == 3)
    A0a.ajouter_multvectT(X0, Ya);
  operator_multiply(X0, -1, VECT_ALL_ITEMS);
  if(nblocs == 3)
    {
      le_precond_a->preconditionner(Aaa,Ya,Xa);
      operator_multiply(Xa, -alpha_a, VECT_ALL_ITEMS);
      Aaa.ajouter_multvect(Xa, Ya);
      A1a.ajouter_multvect(Xa, Y1);
      A0a.ajouter_multvect(Xa, Y0);
      operator_multiply(Xa, -1, VECT_ALL_ITEMS);
    }
  // X contient S,
  F=solution;
  // Diagonale :
 
  A11.multvect(Y1,X1);
  operator_multiply(X1, 1./alpha_1, VECT_ALL_ITEMS);
  A00.multvect(Y0,X0);
  operator_multiply(X0, 1./alpha_0, VECT_ALL_ITEMS);
  if(nblocs == 3)
    {
      Aaa.multvect(Ya,Xa);
      operator_multiply(Xa, 1./alpha_a, VECT_ALL_ITEMS);
    }
  // X contient T,
  F=solution;
 
  // Remontee :
 
  if(nblocs == 3)
    {
      le_precond_a->preconditionner(Aaa,Ya,Xa);
      operator_multiply(Xa, -alpha_a, VECT_ALL_ITEMS);
      Aaa.ajouter_multvect(Xa, Ya);
      A1a.ajouter_multvect(Xa, Y1);
      A0a.ajouter_multvect(Xa, Y0);
      operator_multiply(Xa, -1., VECT_ALL_ITEMS);
    }
  le_precond_0->preconditionner(A00,Y0,X0);
  operator_multiply(X0, -alpha_0, VECT_ALL_ITEMS);
  A00.ajouter_multvect(X0, Y0);
  A01.ajouter_multvectT(X0, Y1);
  if(nblocs == 3)
    A0a.ajouter_multvectT(X0, Ya);
  operator_multiply(X0, -1., VECT_ALL_ITEMS);
  le_precond_1->preconditionner(A11,Y1,X1);
  operator_multiply(X1, -alpha_1, VECT_ALL_ITEMS);
  A11.ajouter_multvect(X1, Y1);
  A01.ajouter_multvect(X1, Y0);
  if(nblocs == 3)
    A1a.ajouter_multvectT(X1, Ya);
  operator_multiply(X1, -1., VECT_ALL_ITEMS);
#ifdef TRACE
  matrice.multvect(solution, F);
  psc=mp_prodscal(F,b);
  assert(psc>0);
  pscF=mp_prodscal(F,F);
  Cout << finl <<"cos(angle) " << psc*psc/(pscF*pscb) << finl;
  Cout << finl <<"(F,b) " << psc << finl;
  Cout << finl <<"(b,b) " << pscb << finl;
  Cout << finl <<"(F,F) " << pscF << finl;
  F.ajoute(-psc/pscb,b);
 
  Cout << finl <<"(F0,F0) " << mp_prodscal(Y0,Y0) << finl;
  Cout << finl <<"(F1,F1) " << mp_prodscal(Y1,Y1) << finl;
  if(nblocs == 3)
    Cout << finl <<"(Fa,Fa) " << mp_prodscal(Ya,Ya) << finl;
#endif
 
  return 1;
}