TsqrRandomizer.hpp

// @HEADER
// *****************************************************************************
//                 Anasazi: Block Eigensolvers Package
//
// Copyright 2004 NTESS and the Anasazi contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#ifndef __TSQR_Trilinos_Randomizer_hpp
#define __TSQR_Trilinos_Randomizer_hpp

#include "AnasaziConfigDefs.hpp"
#include "TsqrTypeAdaptor.hpp"
#include "TsqrCommFactory.hpp"

#include "Tsqr_ScalarTraits.hpp"
#include "Tsqr_Random_GlobalMatrix.hpp"

#include <string>


namespace TSQR {
  namespace Trilinos {
    template< class S, class LO, class GO, class MV, class Gen >
    class Randomizer {
    public:
      typedef S   scalar_type;
      typedef LO  local_ordinal_type;
      typedef GO  global_ordinal_type;
      typedef MV  multivector_type;
      typedef Gen normalgen_type;
      typedef Teuchos::RCP< Gen > normalgen_ptr;
      typedef TSQR::Random::MatrixGenerator< S, LO, Gen > matgen_type;

      typedef typename TSQR::ScalarTraits< S >::magnitude_type magnitude_type;

      typedef TsqrTypeAdaptor< S, LO, GO, MV >      type_adaptor;
      typedef typename type_adaptor::comm_type      comm_type;
      typedef typename type_adaptor::comm_ptr       comm_ptr;
      typedef Teuchos::RCP< MessengerBase< LO > > ordinal_messenger_ptr;
      typedef Teuchos::RCP< MessengerBase< S > >  scalar_messenger_ptr;

      virtual ~Randomizer() {}

      virtual void
      randomMultiVector (multivector_type& A, 
       const magnitude_type singularValues[])
      {
  using TSQR::Random::randomGlobalMatrix;
  using Teuchos::ArrayRCP;
  typedef MatView< local_ordinal_type, scalar_type > matview_type;

  local_ordinal_type nrowsLocal, ncols, LDA;
  fetchDims (A, nrowsLocal, ncols, LDA);
  ArrayRCP< scalar_type > A_ptr = fetchNonConstView (A);
  matview_type A_view (nrowsLocal, ncols, A_ptr.get(), LDA);

  randomGlobalMatrix (pGen_.get(), A_view, singularValues,
          pOrdinalMessenger_.get(), pScalarMessenger_.get());
      }

    protected:
      void 
      init (const multivector_type& mv,
      const normalgen_ptr& pGen)
      {
  pGen_ = pGen;
  // This is done in a multivector type - dependent way.
  fetchMessengers (mv, pScalarMessenger_, pOrdinalMessenger_);
      }

    private:
      virtual void 
      fetchDims (const multivector_type& A, 
     local_ordinal_type& nrowsLocal, 
     local_ordinal_type& ncols, 
     local_ordinal_type& LDA) const = 0;

      virtual Teuchos::ArrayRCP< scalar_type > 
      fetchNonConstView (multivector_type& A) const = 0;

      virtual void
      fetchMessengers (const multivector_type& mv,
           scalar_messenger_ptr& pScalarMessenger,
           ordinal_messenger_ptr& pOrdinalMessenger) const = 0;

      normalgen_ptr pGen_;
      ordinal_messenger_ptr pOrdinalMessenger_;
      scalar_messenger_ptr pScalarMessenger_;
    };

  } // namespace Trilinos
} // namespace TSQR

#endif // __TSQR_Trilinos_Randomizer_hpp