ReferenceVariableVerletDynamics.h

/* Portions copyright (c) 2006-2009 Stanford University and Simbios.
 * Contributors: Peter Eastman, Pande Group
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject
 * to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef __ReferenceVariableVerletDynamics_H__
#define __ReferenceVariableVerletDynamics_H__

#include "ReferenceDynamics.h"

// ---------------------------------------------------------------------------------------

class ReferenceVariableVerletDynamics : public ReferenceDynamics {

   private:

      enum TwoDArrayIndicies { xPrime2D, vPrime2D, Max2DArrays };
      enum OneDArrayIndicies { InverseMasses, Max1DArrays };
      RealOpenMM _accuracy, _lastStepSize;

   public:

      /**---------------------------------------------------------------------------------------

         Constructor

         @param numberOfAtoms  number of atoms
         @param deltaT         initial delta t for dynamics
         @param accuracy       required accuracy

         --------------------------------------------------------------------------------------- */

       ReferenceVariableVerletDynamics( int numberOfAtoms, RealOpenMM deltaT, RealOpenMM accuracy );

      /**---------------------------------------------------------------------------------------

         Destructor

         --------------------------------------------------------------------------------------- */

       ~ReferenceVariableVerletDynamics( );

      /**---------------------------------------------------------------------------------------

         Get the required accuracy

         @return accuracy

         --------------------------------------------------------------------------------------- */

      RealOpenMM getAccuracy( void ) const;

      /**---------------------------------------------------------------------------------------

         Set the required accuracy

         --------------------------------------------------------------------------------------- */

      void setAccuracy( RealOpenMM accuracy );

      /**---------------------------------------------------------------------------------------

         Get the actual size of the last step that was taken

         @return step size

         --------------------------------------------------------------------------------------- */

      RealOpenMM getLastStepSize( void ) const;

      /**---------------------------------------------------------------------------------------

         Print parameters

         @param message message

         @return ReferenceDynamics::DefaultReturn

         --------------------------------------------------------------------------------------- */

      int printParameters( std::stringstream& message ) const;

      /**---------------------------------------------------------------------------------------

         Update

         @param numberOfAtoms       number of atoms
         @param atomCoordinates     atom coordinates
         @param velocities          velocities
         @param forces              forces
         @param masses              atom masses

         @return ReferenceDynamics::DefaultReturn

         --------------------------------------------------------------------------------------- */

      int update( int numberOfAtoms, RealOpenMM** atomCoordinates,
                  RealOpenMM** velocities, RealOpenMM** forces, RealOpenMM* masses );

};

// ---------------------------------------------------------------------------------------

#endif // __ReferenceVariableVerletDynamics_H__