Thyra_DefaultZeroLinearOp.hpp

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// 
//    Thyra: Interfaces and Support for Abstract Numerical Algorithms
//                 Copyright (2004) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
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#ifndef THYRA_DEFAULT_ZERO_LINEAR_OP_HPP
#define THYRA_DEFAULT_ZERO_LINEAR_OP_HPP

#include "Thyra_DefaultZeroLinearOpDecl.hpp"
#include "Thyra_VectorStdOps.hpp"
#include "Teuchos_arrayArg.hpp"

namespace Thyra {

// Constructors/initializers/accessors

template<class Scalar>
DefaultZeroLinearOp<Scalar>::DefaultZeroLinearOp()
{}

template<class Scalar>
DefaultZeroLinearOp<Scalar>::DefaultZeroLinearOp(
  const Teuchos::RCP<const VectorSpaceBase<Scalar> >   &range
  ,const Teuchos::RCP<const VectorSpaceBase<Scalar> >  &domain
  )
{
  initialize(range,domain);
}

template<class Scalar>
void DefaultZeroLinearOp<Scalar>::initialize(
  const Teuchos::RCP<const VectorSpaceBase<Scalar> >   &range
  ,const Teuchos::RCP<const VectorSpaceBase<Scalar> >  &domain
  )
{
  range_ = range.assert_not_null();
  domain_ = domain.assert_not_null();
}

template<class Scalar>
void DefaultZeroLinearOp<Scalar>::uninitialize()
{
  range_ = Teuchos::null;
  domain_ = Teuchos::null;
}

// Overridden from LinearOpBase
  
template<class Scalar>
Teuchos::RCP< const VectorSpaceBase<Scalar> >
DefaultZeroLinearOp<Scalar>::range() const
{
  return range_;
}

template<class Scalar>
Teuchos::RCP< const VectorSpaceBase<Scalar> >
DefaultZeroLinearOp<Scalar>::domain() const
{
  return domain_;
}
  
template<class Scalar>
Teuchos::RCP<const LinearOpBase<Scalar> >
DefaultZeroLinearOp<Scalar>::clone() const
{
  typedef DefaultZeroLinearOp<Scalar> this_t;
  if(range_.get())
    return Teuchos::rcp(new this_t(range_,domain_));
  return Teuchos::rcp(new this_t());
}
  
// Overridden from Teuchos::Describable

template<class Scalar>
std::string DefaultZeroLinearOp<Scalar>::description() const
{
  typedef Teuchos::ScalarTraits<Scalar>  ST;
  std::ostringstream oss;
  oss
    << "Thyra::DefaultZeroLinearOp<" << ST::name() << ">{"
    << "range="<<(range_.get()?range_->description():"NULL")
    << ",domain="<<(domain_.get()?domain_->description():"NULL")
    << "}";
  return oss.str();
}

// protected

// Overridden from SingleScalarLinearOpBase

template<class Scalar>
bool DefaultZeroLinearOp<Scalar>::opSupported(ETransp M_trans) const
{
  return true;
}

template<class Scalar>
void DefaultZeroLinearOp<Scalar>::apply(
  const ETransp                     M_trans
  ,const MultiVectorBase<Scalar>    &X
  ,MultiVectorBase<Scalar>          *Y
  ,const Scalar                     alpha
  ,const Scalar                     beta
  ) const
{
#ifdef TEUCHOS_DEBUG
  THYRA_ASSERT_LINEAR_OP_MULTIVEC_APPLY_SPACES(
    "DefaultZeroLinearOp<Scalar>::apply(...)",*this,M_trans,X,Y
    );
#endif // TEUCHOS_DEBUG  
  scale(beta,Y);
}

} // end namespace Thyra

template<class Scalar>
Teuchos::RCP<const Thyra::LinearOpBase<Scalar> >
Thyra::zero(
  const Teuchos::RCP<const VectorSpaceBase<Scalar> >   &range
  ,const Teuchos::RCP<const VectorSpaceBase<Scalar> >  &domain
  )
{
  return Teuchos::rcp(new DefaultZeroLinearOp<Scalar>(range,domain));
}

#endif  // THYRA_DEFAULT_ZERO_LINEAR_OP_HPP

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