Epetra_SerialDenseSolver.cpp

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#include "Epetra_SerialDenseSolver.h"
#include "Epetra_SerialDenseMatrix.h"
 
//=============================================================================
Epetra_SerialDenseSolver::Epetra_SerialDenseSolver()
  : Epetra_CompObject(),
    Epetra_BLAS(),
    Epetra_LAPACK(),
    Equilibrate_(false),
    ShouldEquilibrate_(false),
    A_Equilibrated_(false),
    B_Equilibrated_(false),
    Transpose_(false),
    Factored_(false),
    EstimateSolutionErrors_(false),
    SolutionErrorsEstimated_(false),
    Solved_(false),
    Inverted_(false),
    ReciprocalConditionEstimated_(false),
    RefineSolution_(false),
    SolutionRefined_(false),
    TRANS_('N'),
    M_(0),
    N_(0),
    Min_MN_(0),
    NRHS_(0),
    LDA_(0),
    LDAF_(0),
    LDB_(0),
    LDX_(0),
    INFO_(0),
    LWORK_(0),
    IPIV_(0),
    IWORK_(0),
    ANORM_(0.0),
    RCOND_(0.0),
    ROWCND_(0.0),
    COLCND_(0.0),
    AMAX_(0.0),
    Matrix_(0),
    LHS_(0),
    RHS_(0),
    Factor_(0),
    A_(0),
    FERR_(0),
    BERR_(0),
    AF_(0),
    WORK_(0),
    R_(0),
    C_(0),
    B_(0),
    X_(0)
{
  InitPointers();
  ResetMatrix();
  ResetVectors();
}
//=============================================================================
Epetra_SerialDenseSolver::~Epetra_SerialDenseSolver()
{
  DeleteArrays();
}
//=============================================================================
void Epetra_SerialDenseSolver::InitPointers()
{
  IWORK_ = 0;
  FERR_ = 0;
  BERR_ = 0;
  Factor_ =0;
  Matrix_ =0;
  AF_ = 0;
  IPIV_ = 0;
  WORK_ = 0;
  R_ = 0;
  C_ = 0;
  INFO_ = 0;
  LWORK_ = 0;
}
//=============================================================================
void Epetra_SerialDenseSolver::DeleteArrays()
{
  if (IWORK_ != 0) {delete [] IWORK_; IWORK_ = 0;}
  if (FERR_ != 0)  {delete [] FERR_; FERR_ = 0;}
  if (BERR_ != 0)  {delete [] BERR_; BERR_ = 0;}
  if (Factor_ != Matrix_ && Factor_ != 0)   {delete Factor_; Factor_ = 0;}
  if (Factor_ !=0) Factor_ = 0;
  if (AF_ !=0) AF_ = 0;
  if (IPIV_ != 0)  {delete [] IPIV_;IPIV_ = 0;}
  if (WORK_ != 0)  {delete [] WORK_;WORK_ = 0;}
  if (R_ != 0 && R_ != C_)     {delete [] R_;R_ = 0;}
  if (R_ != 0) R_ = 0;
  if (C_ != 0)     {delete [] C_;C_ = 0;}
  INFO_ = 0;
  LWORK_ = 0;
}
//=============================================================================
void Epetra_SerialDenseSolver::ResetMatrix()
{
  DeleteArrays();
  ResetVectors();
  Matrix_ = 0;
  Factor_ = 0;
  A_Equilibrated_ = false;
  Factored_ = false;
  Inverted_ = false;
  M_ = 0;
  N_ = 0;
  Min_MN_ = 0;
  LDA_ = 0;
  LDAF_ = 0;
  ANORM_ = -1.0;
  RCOND_ = -1.0;
  ROWCND_ = -1.0;
  COLCND_ = -1.0;
  AMAX_ = -1.0;
  A_ = 0;
 
}
//=============================================================================
int Epetra_SerialDenseSolver::SetMatrix(Epetra_SerialDenseMatrix & A_in) {
  ResetMatrix();
  Matrix_ = &A_in;
  Factor_ = &A_in;
  M_ = A_in.M();
  N_ = A_in.N();
  Min_MN_ = EPETRA_MIN(M_,N_);
  LDA_ = A_in.LDA();
  LDAF_ = LDA_;
  A_ = A_in.A();
  AF_ = A_in.A();
  return(0);
}
//=============================================================================
void Epetra_SerialDenseSolver::ResetVectors()
{
  LHS_ = 0;
  RHS_ = 0;
  B_ = 0;
  X_ = 0;
  ReciprocalConditionEstimated_ = false;
  SolutionRefined_ = false;
  Solved_ = false;
  SolutionErrorsEstimated_ = false;
  B_Equilibrated_ = false;
  NRHS_ = 0;
  LDB_ = 0;
  LDX_ = 0;
}
//=============================================================================
int Epetra_SerialDenseSolver::SetVectors(Epetra_SerialDenseMatrix & X_in, Epetra_SerialDenseMatrix & B_in)
{
  if (B_in.M()!=X_in.M() || B_in.N() != X_in.N()) EPETRA_CHK_ERR(-1);
  if (B_in.A()==0) EPETRA_CHK_ERR(-2);
  if (B_in.LDA()<1) EPETRA_CHK_ERR(-3);
  if (X_in.A()==0) EPETRA_CHK_ERR(-4);
  if (X_in.LDA()<1) EPETRA_CHK_ERR(-5);
 
  ResetVectors();
  LHS_ = &X_in;
  RHS_ = &B_in;
  NRHS_ = B_in.N();
 
  B_ = B_in.A();
  LDB_ = B_in.LDA();
  X_ = X_in.A();
  LDX_ = X_in.LDA();
  return(0);
}
//=============================================================================
void Epetra_SerialDenseSolver::EstimateSolutionErrors(bool Flag) {
  EstimateSolutionErrors_ = Flag;
  // If the errors are estimated, this implies that the solution must be refined
  RefineSolution_ = RefineSolution_ || Flag;
  return;
}
//=============================================================================
int Epetra_SerialDenseSolver::Factor(void) {
  if (Factored()) return(0); // Already factored
  if (Inverted()) EPETRA_CHK_ERR(-100); // Cannot factor inverted matrix
  int ierr = 0;
 
  ANORM_ = Matrix_->OneNorm(); // Compute 1-Norm of A
 
 
  // If we want to refine the solution, then the factor must
  // be stored separatedly from the original matrix
 
  if (A_ == AF_)
    if (RefineSolution_ ) {
      Factor_ = new Epetra_SerialDenseMatrix(*Matrix_);
      AF_ = Factor_->A();
      LDAF_ = Factor_->LDA();
    }
 
  if (Equilibrate_) ierr = EquilibrateMatrix();
 
  if (ierr!=0) EPETRA_CHK_ERR(ierr-2);
 
  if (IPIV_==0) IPIV_ = new int[Min_MN_]; // Allocated Pivot vector if not already done.
 
  GETRF (M_, N_, AF_, LDAF_, IPIV_, &INFO_);
 
  Factored_ = true;
  double DN = N_;
  UpdateFlops(2.0*(DN*DN*DN)/3.0);
 
  EPETRA_CHK_ERR(INFO_);
  return(0);
 
}
 
//=============================================================================
int Epetra_SerialDenseSolver::Solve(void) {
  int ierr = 0;
 
  // We will call one of four routines depending on what services the user wants and
  // whether or not the matrix has been inverted or factored already.
  //
  // If the matrix has been inverted, use DGEMM to compute solution.
  // Otherwise, if the user want the matrix to be equilibrated or wants a refined solution, we will
  // call the X interface.
  // Otherwise, if the matrix is already factored we will call the TRS interface.
  // Otherwise, if the matrix is unfactored we will call the SV interface.
 
 
 
  if (Equilibrate_) {
    ierr = EquilibrateRHS();
    B_Equilibrated_ = true;
  }
  EPETRA_CHK_ERR(ierr);
  if (A_Equilibrated_ && !B_Equilibrated_) EPETRA_CHK_ERR(-1); // Matrix and vectors must be similarly scaled
  if (!A_Equilibrated_ && B_Equilibrated_) EPETRA_CHK_ERR(-2);
  if (B_==0) EPETRA_CHK_ERR(-3); // No B
  if (X_==0) EPETRA_CHK_ERR(-4); // No X
 
  if (ShouldEquilibrate() && !A_Equilibrated_) ierr = 1; // Warn that the system should be equilibrated.
 
  double DN = N_;
  double DNRHS = NRHS_;
  if (Inverted()) {
 
    if (B_==X_) EPETRA_CHK_ERR(-100); // B and X must be different for this case
 
    GEMM(TRANS_, 'N', N_, NRHS_, N_, 1.0, AF_, LDAF_,
    B_, LDB_, 0.0, X_, LDX_);
    if (INFO_!=0) EPETRA_CHK_ERR(INFO_);
    UpdateFlops(2.0*DN*DN*DNRHS);
    Solved_ = true;
  }
  else {
 
    if (!Factored()) Factor(); // Matrix must be factored
 
    if (B_!=X_) {
       *LHS_ = *RHS_; // Copy B to X if needed
       X_ = LHS_->A(); LDX_ = LHS_->LDA();
    }
    GETRS(TRANS_, N_, NRHS_, AF_, LDAF_, IPIV_, X_, LDX_, &INFO_);
    if (INFO_!=0) EPETRA_CHK_ERR(INFO_);
    UpdateFlops(2.0*DN*DN*DNRHS);
    Solved_ = true;
 
  }
  int ierr1=0;
  if (RefineSolution_ && !Inverted()) ierr1 = ApplyRefinement();
  if (ierr1!=0) EPETRA_CHK_ERR(ierr1)
  else
    EPETRA_CHK_ERR(ierr);
 
  if (Equilibrate_) ierr1 = UnequilibrateLHS();
  EPETRA_CHK_ERR(ierr1);
  return(0);
}
//=============================================================================
int Epetra_SerialDenseSolver::ApplyRefinement(void)
{
  double DN = N_;
  double DNRHS = NRHS_;
  if (!Solved()) EPETRA_CHK_ERR(-100); // Must have an existing solution
  if (A_==AF_) EPETRA_CHK_ERR(-101); // Cannot apply refine if no original copy of A.
 
  if (FERR_ != 0) delete [] FERR_; // Always start with a fresh copy of FERR_, since NRHS_ may change
  FERR_ = new double[NRHS_];
  if (BERR_ != 0) delete [] BERR_; // Always start with a fresh copy of BERR_, since NRHS_ may change
  BERR_ = new double[NRHS_];
  AllocateWORK();
  AllocateIWORK();
 
  GERFS(TRANS_, N_, NRHS_, A_, LDA_, AF_, LDAF_, IPIV_,
         B_, LDB_, X_, LDX_, FERR_, BERR_,
         WORK_, IWORK_, &INFO_);
 
 
  SolutionErrorsEstimated_ = true;
  ReciprocalConditionEstimated_ = true;
  SolutionRefined_ = true;
 
  UpdateFlops(2.0*DN*DN*DNRHS); // Not sure of count
 
  EPETRA_CHK_ERR(INFO_);
  return(0);
 
}
 
//=============================================================================
int Epetra_SerialDenseSolver::ComputeEquilibrateScaling(void) {
  if (R_!=0) return(0); // Already computed
 
  double DM = M_;
  double DN = N_;
  R_ = new double[M_];
  C_ = new double[N_];
 
  GEEQU (M_, N_, AF_, LDAF_, R_, C_, &ROWCND_, &COLCND_, &AMAX_, &INFO_);
  if (INFO_ != 0) EPETRA_CHK_ERR(INFO_);
 
  if (COLCND_<0.1 || ROWCND_<0.1 || AMAX_ < Epetra_Underflow || AMAX_ > Epetra_Overflow) ShouldEquilibrate_ = true;
 
  UpdateFlops(4.0*DM*DN);
 
  return(0);
}
 
//=============================================================================
int Epetra_SerialDenseSolver::EquilibrateMatrix(void)
{
  int i, j;
  int ierr = 0;
 
  double DN = N_;
  double DM = M_;
 
  if (A_Equilibrated_) return(0); // Already done
  if (R_==0) ierr = ComputeEquilibrateScaling(); // Compute R and C if needed
  if (ierr!=0) EPETRA_CHK_ERR(ierr);
  if (A_==AF_) {
    double * ptr;
    for (j=0; j<N_; j++) {
      ptr = A_ + j*LDA_;
      double s1 = C_[j];
      for (i=0; i<M_; i++) {
  *ptr = *ptr*s1*R_[i];
  ptr++;
      }
    }
    UpdateFlops(2.0*DM*DN);
  }
  else {
    double * ptr;
    double * ptr1;
    for (j=0; j<N_; j++) {
      ptr = A_ + j*LDA_;
      ptr1 = AF_ + j*LDAF_;
      double s1 = C_[j];
      for (i=0; i<M_; i++) {
  *ptr = *ptr*s1*R_[i];
  ptr++;
  *ptr1 = *ptr1*s1*R_[i];
  ptr1++;
      }
    }
    UpdateFlops(4.0*DM*DN);
  }
 
  A_Equilibrated_ = true;
 
  return(0);
}
 
//=============================================================================
int Epetra_SerialDenseSolver::EquilibrateRHS(void)
{
  int i, j;
  int ierr = 0;
 
  if (B_Equilibrated_) return(0); // Already done
  if (R_==0) ierr = ComputeEquilibrateScaling(); // Compute R and C if needed
  if (ierr!=0) EPETRA_CHK_ERR(ierr);
 
  double * R_tmp = R_;
  if (Transpose_) R_tmp = C_;
 
  double * ptr;
  for (j=0; j<NRHS_; j++) {
    ptr = B_ + j*LDB_;
    for (i=0; i<M_; i++) {
      *ptr = *ptr*R_tmp[i];
      ptr++;
    }
  }
 
 
  B_Equilibrated_ = true;
  UpdateFlops((double) N_*(double) NRHS_);
 
  return(0);
}
 
//=============================================================================
int Epetra_SerialDenseSolver::UnequilibrateLHS(void)
{
  int i, j;
 
  if (!B_Equilibrated_) return(0); // Nothing to do
 
  double * C_tmp = C_;
  if (Transpose_) C_tmp = R_;
 
  double * ptr;
  for (j=0; j<NRHS_; j++) {
    ptr = X_ + j*LDX_;
    for (i=0; i<N_; i++) {
      *ptr = *ptr*C_tmp[i];
      ptr++;
    }
  }
 
 
  UpdateFlops((double) N_ *(double) NRHS_);
 
  return(0);
}
 
//=============================================================================
int Epetra_SerialDenseSolver::Invert(void)
{
  if (!Factored()) Factor(); // Need matrix factored.
 
  /* This section work with LAPACK Version 3.0 only
  // Setting LWORK = -1 and calling GETRI will return optimal work space size in WORK_TMP
  int LWORK_TMP = -1;
  double WORK_TMP;
  GETRI ( N_, AF_, LDAF_, IPIV_, &WORK_TMP, &LWORK_TMP, &INFO_);
  LWORK_TMP = WORK_TMP; // Convert to integer
  if (LWORK_TMP>LWORK_) {
  if (WORK_!=0) delete [] WORK_;
  LWORK_ = LWORK_TMP;
  WORK_ = new double[LWORK_];
  }
  */
  // This section will work with any version of LAPACK
  AllocateWORK();
 
  GETRI ( N_, AF_, LDAF_, IPIV_, WORK_, &LWORK_, &INFO_);
 
  double DN = N_;
  UpdateFlops((DN*DN*DN));
  Inverted_ = true;
  Factored_ = false;
 
  EPETRA_CHK_ERR(INFO_);
  return(0);
}
 
//=============================================================================
int Epetra_SerialDenseSolver::ReciprocalConditionEstimate(double & Value)
{
  int ierr = 0;
  if (ReciprocalConditionEstimated()) {
    Value = RCOND_;
    return(0); // Already computed, just return it.
  }
 
  if (ANORM_<0.0) ANORM_ = Matrix_->OneNorm();
  if (!Factored()) ierr = Factor(); // Need matrix factored.
  if (ierr!=0) EPETRA_CHK_ERR(ierr-2);
 
  AllocateWORK();
  AllocateIWORK();
  // We will assume a one-norm condition number
  GECON( '1', N_, AF_, LDAF_, ANORM_, &RCOND_, WORK_, IWORK_, &INFO_);
  ReciprocalConditionEstimated_ = true;
  Value = RCOND_;
  UpdateFlops(2*N_*N_); // Not sure of count
  EPETRA_CHK_ERR(INFO_);
  return(0);
}
//=============================================================================
void Epetra_SerialDenseSolver::Print(std::ostream& os) const {
 
  if (Matrix_!=0) os << "Solver Matrix"          << std::endl << *Matrix_ << std::endl;
  if (Factor_!=0) os << "Solver Factored Matrix" << std::endl << *Factor_ << std::endl;
  if (LHS_   !=0) os << "Solver LHS"             << std::endl << *LHS_    << std::endl;
  if (RHS_   !=0) os << "Solver RHS"             << std::endl << *RHS_    << std::endl;
 
}