Teko_StridedEpetraOperator.cpp

// @HEADER
// *****************************************************************************
//      Teko: A package for block and physics based preconditioning
//
// Copyright 2010 NTESS and the Teko contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#include "Epetra/Teko_StridedEpetraOperator.hpp"
#include "Epetra/Teko_StridedMappingStrategy.hpp"
#include "Epetra/Teko_ReorderedMappingStrategy.hpp"

#include "Teuchos_VerboseObject.hpp"

#include "Thyra_LinearOpBase.hpp"
#include "Thyra_EpetraLinearOp.hpp"
#include "Thyra_EpetraThyraWrappers.hpp"
#include "Thyra_DefaultProductMultiVector.hpp"
#include "Thyra_DefaultProductVectorSpace.hpp"
#include "Thyra_DefaultBlockedLinearOp.hpp"
#include "Thyra_get_Epetra_Operator.hpp"

#include "Epetra_Vector.h"
#include "EpetraExt_MultiVectorOut.h"
#include "EpetraExt_RowMatrixOut.h"

#include "Teko_Utilities.hpp"

namespace Teko {
namespace Epetra {

using Teuchos::RCP;
using Teuchos::rcp;
using Teuchos::rcp_dynamic_cast;

StridedEpetraOperator::StridedEpetraOperator(int numVars,
                                             const Teuchos::RCP<const Epetra_Operator>& content,
                                             const std::string& label)
    : Teko::Epetra::EpetraOperatorWrapper(), label_(label) {
  std::vector<int> vars;

  // build vector describing the sub maps
  for (int i = 0; i < numVars; i++) vars.push_back(1);

  SetContent(vars, content);
}

StridedEpetraOperator::StridedEpetraOperator(const std::vector<int>& vars,
                                             const Teuchos::RCP<const Epetra_Operator>& content,
                                             const std::string& label)
    : Teko::Epetra::EpetraOperatorWrapper(), label_(label) {
  SetContent(vars, content);
}

void StridedEpetraOperator::SetContent(const std::vector<int>& vars,
                                       const Teuchos::RCP<const Epetra_Operator>& content) {
  fullContent_    = content;
  stridedMapping_ = rcp(new StridedMappingStrategy(
      vars, Teuchos::rcpFromRef(fullContent_->OperatorDomainMap()), fullContent_->Comm()));
  SetMapStrategy(stridedMapping_);

  // build thyra operator
  BuildBlockedOperator();
}

void StridedEpetraOperator::BuildBlockedOperator() {
  TEUCHOS_ASSERT(stridedMapping_ != Teuchos::null);

  // get a CRS matrix
  const RCP<const Epetra_CrsMatrix> crsContent =
      rcp_dynamic_cast<const Epetra_CrsMatrix>(fullContent_);

  // ask the strategy to build the Thyra operator for you
  if (stridedOperator_ == Teuchos::null) {
    stridedOperator_ = stridedMapping_->buildBlockedThyraOp(crsContent, label_);
  } else {
    const RCP<Thyra::BlockedLinearOpBase<double> > blkOp =
        rcp_dynamic_cast<Thyra::BlockedLinearOpBase<double> >(stridedOperator_, true);
    stridedMapping_->rebuildBlockedThyraOp(crsContent, blkOp);
  }

  // set whatever is returned
  SetOperator(stridedOperator_, false);

  // reorder if neccessary
  if (reorderManager_ != Teuchos::null) Reorder(*reorderManager_);
}

const Teuchos::RCP<const Epetra_Operator> StridedEpetraOperator::GetBlock(int i, int j) const {
  const RCP<const Thyra::BlockedLinearOpBase<double> > blkOp =
      Teuchos::rcp_dynamic_cast<const Thyra::BlockedLinearOpBase<double> >(getThyraOp());

  return Thyra::get_Epetra_Operator(*blkOp->getBlock(i, j));
}

void StridedEpetraOperator::Reorder(const BlockReorderManager& brm) {
  reorderManager_ = rcp(new BlockReorderManager(brm));

  // build reordered objects
  RCP<const MappingStrategy> reorderMapping =
      rcp(new ReorderedMappingStrategy(*reorderManager_, stridedMapping_));
  RCP<const Thyra::BlockedLinearOpBase<double> > blockOp =
      rcp_dynamic_cast<const Thyra::BlockedLinearOpBase<double> >(stridedOperator_);

  RCP<const Thyra::LinearOpBase<double> > A = buildReorderedLinearOp(*reorderManager_, blockOp);

  // set them as working values
  SetMapStrategy(reorderMapping);
  SetOperator(A, false);
}

void StridedEpetraOperator::RemoveReording() {
  SetMapStrategy(stridedMapping_);
  SetOperator(stridedOperator_, false);
  reorderManager_ = Teuchos::null;
}

void StridedEpetraOperator::WriteBlocks(const std::string& prefix) const {
  RCP<Thyra::PhysicallyBlockedLinearOpBase<double> > blockOp =
      rcp_dynamic_cast<Thyra::PhysicallyBlockedLinearOpBase<double> >(stridedOperator_);

  // get size of strided block operator
  int rows = Teko::blockRowCount(blockOp);

  for (int i = 0; i < rows; i++) {
    for (int j = 0; j < rows; j++) {
      // get the row matrix object (Note: can't use "GetBlock" method b/c matrix might be reordered)
      RCP<const Epetra_RowMatrix> mat = Teuchos::rcp_dynamic_cast<const Epetra_RowMatrix>(
          Thyra::get_Epetra_Operator(*blockOp->getBlock(i, j)));

      // write to file
      EpetraExt::RowMatrixToMatrixMarketFile(formatBlockName(prefix, i, j, rows).c_str(), *mat);
    }
  }
}

std::string StridedEpetraOperator::PrintNorm(const eNormType& nrmType, const char newline) {
  BlockedLinearOp blockOp = toBlockedLinearOp(stridedOperator_);

  // get size of strided block operator
  int rowCount = Teko::blockRowCount(blockOp);
  int colCount = Teko::blockRowCount(blockOp);

  std::stringstream ss;
  ss.precision(4);
  ss << std::scientific;
  for (int row = 0; row < rowCount; row++) {
    for (int col = 0; col < colCount; col++) {
      // get the row matrix object (Note: can't use "GetBlock" method b/c matrix might be reordered)
      RCP<const Epetra_CrsMatrix> mat = Teuchos::rcp_dynamic_cast<const Epetra_CrsMatrix>(
          Thyra::get_Epetra_Operator(*blockOp->getBlock(row, col)));

      // compute the norm
      double norm = 0.0;
      switch (nrmType) {
        case Inf: norm = mat->NormInf(); break;
        case One: norm = mat->NormOne(); break;
        case Frobenius: norm = mat->NormFrobenius(); break;
        default:
          TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error,
                                     "StridedEpetraOperator::eNormType incorrectly specified");
      }

      ss << norm << " ";
    }
    ss << newline;
  }

  return ss.str();
}

bool StridedEpetraOperator::testAgainstFullOperator(int count, double tol) const {
  Epetra_Vector xf(OperatorRangeMap());
  Epetra_Vector xs(OperatorRangeMap());
  Epetra_Vector y(OperatorDomainMap());

  // test operator many times
  bool result     = true;
  double diffNorm = 0.0, trueNorm = 0.0;
  for (int i = 0; i < count; i++) {
    xf.PutScalar(0.0);
    xs.PutScalar(0.0);
    y.Random();

    // apply operator
    Apply(y, xs);                // xs = A*y
    fullContent_->Apply(y, xf);  // xf = A*y

    // compute norms
    xs.Update(-1.0, xf, 1.0);
    xs.Norm2(&diffNorm);
    xf.Norm2(&trueNorm);

    // check result
    result &= (diffNorm / trueNorm < tol);
  }

  return result;
}

}  // end namespace Epetra
}  // end namespace Teko