OptiPack_DefaultPolyLineSearchPointEvaluator.hpp

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//    OptiPack: Collection of simple Thyra-based Optimization ANAs
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#ifndef OPTIPACK_DEFAULT_POLY_LINE_SEARCH_POINT_EVALUATOR_HPP
#define OPTIPACK_DEFAULT_POLY_LINE_SEARCH_POINT_EVALUATOR_HPP
 
 
#include "OptiPack_LineSearchPointEvaluatorBase.hpp"
#include "Thyra_VectorStdOps.hpp"
 
 
namespace OptiPack {
 
 
template<typename Scalar>
class DefaultPolyLineSearchPointEvaluator : public LineSearchPointEvaluatorBase<Scalar>
{
public:
 
  typedef typename ScalarTraits<Scalar>::magnitudeType ScalarMag;
 
 
  DefaultPolyLineSearchPointEvaluator();
  
  void initialize(const ArrayView<const RCP<const Thyra::VectorBase<Scalar> > > &vecs);
 
 
 
  virtual void computePoint( const ScalarMag &alpha,
    const Ptr<Thyra::VectorBase<Scalar> > &p
    ) const;
 
 
private:
 
  Array<RCP<const Thyra::VectorBase<Scalar> > > vecs_;
 
};
 
 
template<typename Scalar>
const RCP<DefaultPolyLineSearchPointEvaluator<Scalar> >
defaultPolyLineSearchPointEvaluator()
{
  return Teuchos::rcp(new DefaultPolyLineSearchPointEvaluator<Scalar>);
}
 
 
//
// Implementations
//
 
 
// Constructors/intializers/accessors
 
 
template<typename Scalar>
DefaultPolyLineSearchPointEvaluator<Scalar>::DefaultPolyLineSearchPointEvaluator()
{}
  
 
template<typename Scalar>
void DefaultPolyLineSearchPointEvaluator<Scalar>::initialize(
  const ArrayView<const RCP<const Thyra::VectorBase<Scalar> > > &vecs
  )
{
#ifdef TEUCHOS_DEBUG
  TEUCHOS_ASSERT(vecs.size());
#endif
  vecs_ = vecs;
}
 
 
// Overridden from LineSearchPointEvaluatorBase
 
 
template<typename Scalar>
void DefaultPolyLineSearchPointEvaluator<Scalar>::computePoint( const ScalarMag &alpha,
  const Ptr<Thyra::VectorBase<Scalar> > &p
  ) const
{
  typedef ScalarTraits<Scalar> ST;
  using Teuchos::as;
  using Thyra::V_V;
  using Thyra::Vp_StV;
  V_V( p, *vecs_[0] );
  if (alpha != ST::zero()) {
    ScalarMag alpha_i = alpha;
    const int n = vecs_.size();
    for (int i = 1; i < n; ++i, alpha_i *= alpha) {
      Vp_StV(p, alpha_i, *vecs_[i]); 
    }
  }
}
 
 
} // namespace OptiPack
 
 
#endif // OPTIPACK_DEFAULT_POLY_LINE_SEARCH_POINT_EVALUATOR_HPP