/home/vivien/public_html/.src_seldon/computation/interfaces/direct/SuperLU.cxx

// Copyright (C) 2003-2009 Marc Duruflé
//
// This file is part of the linear-algebra library Seldon,
// http://seldon.sourceforge.net/.
//
// Seldon is free software; you can redistribute it and/or modify it under the
// terms of the GNU Lesser General Public License as published by the Free
// Software Foundation; either version 2.1 of the License, or (at your option)
// any later version.
//
// Seldon is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
// more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with Seldon. If not, see http://www.gnu.org/licenses/.


#ifndef SELDON_FILE_SUPERLU_CXX

#include "SuperLU.hxx"

// The function comes from the Matlab interface to SuperLU. It is part of
// SuperLU package. Its copyright is held by University of California
// Berkeley, Xerox Palo Alto Research Center and Lawrence Berkeley National
// Lab. It is released under a license compatible with the GNU LGPL.
void LUextract(SuperMatrix *L, SuperMatrix *U, double *Lval, int *Lrow,
               int *Lcol, double *Uval, int *Urow, int *Ucol, int *snnzL,
               int *snnzU)
{
  int         i, j, k;
  int         upper;
  int         fsupc, istart, nsupr;
  int         lastl = 0, lastu = 0;
  SCformat    *Lstore;
  NCformat    *Ustore;
  double      *SNptr;

  Lstore = static_cast<SCformat*>(L->Store);
  Ustore = static_cast<NCformat*>(U->Store);
  Lcol[0] = 0;
  Ucol[0] = 0;

  /* for each supernode */
  for (k = 0; k <= Lstore->nsuper; ++k) {

    fsupc = L_FST_SUPC(k);
    istart = L_SUB_START(fsupc);
    nsupr = L_SUB_START(fsupc+1) - istart;
    upper = 1;

    /* for each column in the supernode */
    for (j = fsupc; j < L_FST_SUPC(k+1); ++j) {
      SNptr = &(static_cast<double*>(Lstore->nzval))[L_NZ_START(j)];

      /* Extract U */
      for (i = U_NZ_START(j); i < U_NZ_START(j+1); ++i) {
        Uval[lastu] = (static_cast<double*>(Ustore->nzval))[i];
        Urow[lastu++] = U_SUB(i);
      }
      for (i = 0; i < upper; ++i) { /* upper triangle in the supernode */
        Uval[lastu] = SNptr[i];
        Urow[lastu++] = L_SUB(istart+i);
      }
      Ucol[j+1] = lastu;

      /* Extract L */
      Lval[lastl] = 1.0; /* unit diagonal */
      Lrow[lastl++] = L_SUB(istart + upper - 1);
      for (i = upper; i < nsupr; ++i) {
        Lval[lastl] = SNptr[i];
        Lrow[lastl++] = L_SUB(istart+i);
      }
      Lcol[j+1] = lastl;

      ++upper;

    } /* for j ... */

  } /* for k ... */

  *snnzL = lastl;
  *snnzU = lastu;
}


namespace Seldon
{
  template<class T>
  MatrixSuperLU_Base<T>::MatrixSuperLU_Base()
  {
    n = 0;
    permc_spec = COLAMD;
    Lstore = NULL;
    Ustore = NULL;
    StatInit(&stat);
    set_default_options(&options);
    ShowMessages();
    display_info = false;
    info_facto = 0;
  }


  template<class T>
  MatrixSuperLU_Base<T>::~MatrixSuperLU_Base()
  {
    Clear();
  }



  template<class T>
  template<class Prop, class Allocator>
  void MatrixSuperLU_Base<T>
  ::GetLU(Matrix<double, Prop, ColSparse, Allocator>& Lmat,
          Matrix<double, Prop, ColSparse, Allocator>& Umat,
          bool permuted)
  {
    Lstore = static_cast<SCformat*>(L.Store);
    Ustore = static_cast<NCformat*>(U.Store);

    int Lnnz = Lstore->nnz;
    int Unnz = Ustore->nnz;

    int m = U.nrow;
    int n = U.ncol;

    Vector<double, VectFull, Allocator> Lval(Lnnz);
    Vector<int, VectFull, CallocAlloc<int> > Lrow(Lnnz);
    Vector<int, VectFull, CallocAlloc<int> > Lcol(n + 1);

    Vector<double, VectFull, Allocator> Uval(Unnz);
    Vector<int, VectFull, CallocAlloc<int> > Urow(Unnz);
    Vector<int, VectFull, CallocAlloc<int> > Ucol(n + 1);

    int Lsnnz;
    int Usnnz;
    LUextract(&L, &U, Lval.GetData(), Lrow.GetData(), Lcol.GetData(),
              Uval.GetData(), Urow.GetData(), Ucol.GetData(), &Lsnnz, &Usnnz);

    Lmat.SetData(m, n, Lval, Lcol, Lrow);
    Umat.SetData(m, n, Uval, Ucol, Urow);

    if (!permuted)
      {
        Vector<int> row_perm_orig = perm_r;
        Vector<int> col_perm_orig = perm_c;

        Vector<int> row_perm(n);
        Vector<int> col_perm(n);
        row_perm.Fill();
        col_perm.Fill();

        Sort(row_perm_orig, row_perm);
        Sort(col_perm_orig, col_perm);

        ApplyInversePermutation(Lmat, row_perm, col_perm);
        ApplyInversePermutation(Umat, row_perm, col_perm);
      }
  }



  template<class T>
  template<class Prop, class Allocator>
  void MatrixSuperLU_Base<T>
  ::GetLU(Matrix<double, Prop, RowSparse, Allocator>& Lmat,
          Matrix<double, Prop, RowSparse, Allocator>& Umat,
          bool permuted)
  {
    Lmat.Clear();
    Umat.Clear();

    Matrix<double, Prop, ColSparse, Allocator> Lmat_col;
    Matrix<double, Prop, ColSparse, Allocator> Umat_col;
    GetLU(Lmat_col, Umat_col, permuted);

    Copy(Lmat_col, Lmat);
    Lmat_col.Clear();
    Copy(Umat_col, Umat);
    Umat_col.Clear();
  }



  template<class T>
  const Vector<int>& MatrixSuperLU_Base<T>::GetRowPermutation() const
  {
    return perm_r;
  }



  template<class T>
  const Vector<int>& MatrixSuperLU_Base<T>::GetColPermutation() const
  {
    return perm_c;
  }


  template<class T>
  void MatrixSuperLU_Base<T>::SelectOrdering(colperm_t type)
  {
    permc_spec = type;
  }


  template<class T>
  void MatrixSuperLU_Base<T>::SetPermutation(const IVect& permut)
  {
    permc_spec = MY_PERMC;
    perm_c = permut;
    perm_r = permut;
  }


  template<class T>
  void MatrixSuperLU_Base<T>::Clear()
  {
    if (n > 0)
      {
        // SuperLU objects are cleared
        Destroy_SuperMatrix_Store(&B);
        Destroy_SuperNode_Matrix(&L);
        Destroy_CompCol_Matrix(&U);
        perm_r.Clear();
        perm_c.Clear();
        n = 0;
      }
  }


  template<class T>
  void MatrixSuperLU_Base<T>::HideMessages()
  {
    display_info = false;
  }


  template<class T>
  void MatrixSuperLU_Base<T>::ShowMessages()
  {
    display_info = true;
  }


  template<class T>
  int MatrixSuperLU_Base<T>::GetInfoFactorization() const
  {
    return info_facto;
  }


  template<class Prop, class Storage, class Allocator>
  void MatrixSuperLU<double>::
  FactorizeMatrix(Matrix<double, Prop, Storage, Allocator> & mat,
                  bool keep_matrix)
  {
    // clearing previous factorization
    Clear();

    // conversion in CSC format
    n = mat.GetN();
    Matrix<double, General, ColSparse> Acsr;
    Copy(mat, Acsr);
    if (!keep_matrix)
      mat.Clear();

    SuperMatrix A, AA;
    int nnz = Acsr.GetDataSize();
    dCreate_CompCol_Matrix(&AA, n, n, nnz, Acsr.GetData(), Acsr.GetInd(),
                           Acsr.GetPtr(), SLU_NC, SLU_D, SLU_GE);

    // we get renumbering vectors perm_r and perm_c
    options.ColPerm = permc_spec;
    if (permc_spec != MY_PERMC)
      {
        perm_r.Reallocate(n);
        perm_c.Reallocate(n);
        perm_r.Fill();
        perm_c.Fill();

        get_perm_c(permc_spec, &AA, perm_c.GetData());
      }

    // Original matrix AA is permuted to obtain matrix A.
    Vector<int> etree(n);
    sp_preorder(&options, &AA, perm_c.GetData(), etree.GetData(), &A);

    int panel_size = sp_ienv(1);
    int relax = sp_ienv(2);
    int lwork = 0;

    // Then calling factorization on permuted matrix.
    dgstrf(&options, &A, relax, panel_size, etree.GetData(),
           NULL, lwork, perm_c.GetData(), perm_r.GetData(), &L, &U, &stat,
           &info_facto);

    // Clearing matrices.
    Destroy_CompCol_Permuted(&A);
    Destroy_CompCol_Matrix(&AA);

    if (info_facto == 0 && display_info)
      {
        mem_usage_t mem_usage;
        Lstore = (SCformat *) L.Store;
        Ustore = (NCformat *) U.Store;
        cout << "Number of nonzeros in factor L = " << Lstore->nnz << endl;
        cout << "Number of nonzeros in factor U = " << Ustore->nnz << endl;
        cout << "Number of nonzeros in L+U     = "
             << Lstore->nnz + Ustore->nnz << endl;
        dQuerySpace(&L, &U, &mem_usage);
        cout << "Memory used for factorization in MB: "
             << mem_usage.total_needed / (1024. * 1024.) << endl;
      }

    Acsr.Nullify();
  }


  template<class Allocator2>
  void MatrixSuperLU<double>::Solve(Vector<double, VectFull, Allocator2>& x)
  {
    trans_t trans = NOTRANS;
    int nb_rhs = 1, info;
    // Putting right hand side on SuperLU structure.
    dCreate_Dense_Matrix(&B, x.GetM(), nb_rhs,
                         x.GetData(), x.GetM(), SLU_DN, SLU_D, SLU_GE);

    SuperLUStat_t stat;
    StatInit(&stat);
    // Solving A x = b.
    dgstrs(trans, &L, &U, perm_r.GetData(),
           perm_c.GetData(), &B, &stat, &info);
  }


  template<class TransStatus, class Allocator2>
  void MatrixSuperLU<double>::Solve(const TransStatus& TransA,
                                    Vector<double, VectFull, Allocator2>& x)
  {
    if (TransA.NoTrans())
      {
        Solve(x);
        return;
      }

    trans_t trans = TRANS;
    int nb_rhs = 1, info;
    // Putting right hand side on SuperLU structure.
    dCreate_Dense_Matrix(&B, x.GetM(), nb_rhs,
                         x.GetData(), x.GetM(), SLU_DN, SLU_D, SLU_GE);

    SuperLUStat_t stat;
    StatInit(&stat);
    // Solving A^T x = b.
    dgstrs(trans, &L, &U, perm_r.GetData(),
           perm_c.GetData(), &B, &stat, &info);
  }


  template<class Prop, class Storage, class Allocator>
  void MatrixSuperLU<complex<double> >::
  FactorizeMatrix(Matrix<complex<double>, Prop, Storage, Allocator> & mat,
                  bool keep_matrix)
  {
    // clearing previous factorization
    Clear();

    // conversion in CSR format
    n = mat.GetN();
    Matrix<complex<double>, General, ColSparse> Acsr;
    Copy(mat, Acsr);
    if (!keep_matrix)
      mat.Clear();

    SuperMatrix AA, A;
    int nnz = Acsr.GetDataSize();
    zCreate_CompCol_Matrix(&AA, n, n, nnz,
                           reinterpret_cast<doublecomplex*>(Acsr.GetData()),
                           Acsr.GetInd(), Acsr.GetPtr(),
                           SLU_NC, SLU_Z, SLU_GE);

    // We get renumbering vectors perm_r and perm_c.
    options.ColPerm = permc_spec;
    if (permc_spec != MY_PERMC)
      {
        perm_r.Reallocate(n);
        perm_c.Reallocate(n);
        perm_r.Fill();
        perm_c.Fill();

        get_perm_c(permc_spec, &AA, perm_c.GetData());
      }

    // Permuting matrix.
    Vector<int> etree(n);
    sp_preorder(&options, &AA, perm_c.GetData(), etree.GetData(), &A);

    int panel_size = sp_ienv(1);
    int relax = sp_ienv(2);
    int lwork = 0;

    // Factorization.
    zgstrf(&options, &A, relax, panel_size, etree.GetData(),
           NULL, lwork, perm_c.GetData(), perm_r.GetData(), &L, &U, &stat,
           &info_facto);

    // Clearing matrices.
    Destroy_CompCol_Permuted(&A);
    Destroy_CompCol_Matrix(&AA);

    if (info_facto == 0 && display_info)
      {
        mem_usage_t mem_usage;
        Lstore = (SCformat *) L.Store;
        Ustore = (NCformat *) U.Store;
        cout << "Number of nonzeros in factor L = " << Lstore->nnz<<endl;
        cout << "Number of nonzeros in factor U = " << Ustore->nnz<<endl;
        cout << "Number of nonzeros in L+U     = "
             << Lstore->nnz + Ustore->nnz<<endl;
        zQuerySpace(&L, &U, &mem_usage);
        cout << "Memory used for factorization in MB: "
             << mem_usage.total_needed / (1024. * 1024.) << endl;
      }

    Acsr.Nullify();
  }


  template<class Allocator2>
  void MatrixSuperLU<complex<double> >::
  Solve(Vector<complex<double>, VectFull, Allocator2>& x)
  {
    trans_t trans = NOTRANS;
    int nb_rhs = 1, info;
    zCreate_Dense_Matrix(&B, x.GetM(), nb_rhs,
                         reinterpret_cast<doublecomplex*>(x.GetData()),
                         x.GetM(), SLU_DN, SLU_Z, SLU_GE);

    zgstrs(trans, &L, &U, perm_c.GetData(),
           perm_r.GetData(), &B, &stat, &info);
  }


  template<class TransStatus, class Allocator2>
  void MatrixSuperLU<complex<double> >::
  Solve(const TransStatus& TransA,
        Vector<complex<double>, VectFull, Allocator2>& x)
  {
    if (TransA.NoTrans())
      {
        Solve(x);
        return;
      }

    trans_t trans = TRANS;
    int nb_rhs = 1, info;
    zCreate_Dense_Matrix(&B, x.GetM(), nb_rhs,
                         reinterpret_cast<doublecomplex*>(x.GetData()),
                         x.GetM(), SLU_DN, SLU_Z, SLU_GE);

    zgstrs(trans, &L, &U, perm_c.GetData(),
           perm_r.GetData(), &B, &stat, &info);
  }


  template<class T, class Prop, class Storage, class Allocator>
  void GetLU(Matrix<T, Prop, Storage, Allocator>& A, MatrixSuperLU<T>& mat_lu,
             bool keep_matrix = false)
  {
    mat_lu.FactorizeMatrix(A, keep_matrix);
  }


  template<class T, class Allocator>
  void SolveLU(MatrixSuperLU<T>& mat_lu, Vector<T, VectFull, Allocator>& x)
  {
    mat_lu.Solve(x);
  }


  template<class T, class Allocator>
  void SolveLU(const SeldonTranspose& TransA,
               MatrixSuperLU<T>& mat_lu, Vector<T, VectFull, Allocator>& x)
  {
    mat_lu.Solve(TransA, x);
  }

}

#define SELDON_FILE_SUPERLU_CXX
#endif