src/gromacs/awh/dimparams.h

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  35
  36 /*! \internal \file
  37  *
  38  * \brief
  39  * Declares the DimParams struct and AWH vector types.
  40  *
  41  * This class holds the physical information for a dimension
  42  * of the bias reaction-coordinate grid.
  43  *
  44  * \author Viveca Lindahl
  45  * \author Berk Hess <hess@kth.se>
  46  * \ingroup module_awh
  47  */
  48
  49 #ifndef GMX_AWH_DIMPARAMS_H
  50 #define GMX_AWH_DIMPARAMS_H
  51
  52 #include <vector>
  53
  54 #include "gromacs/math/vectypes.h"
  55 #include "gromacs/utility/basedefinitions.h"
  56
  57 namespace gmx
  58 {
  59
  60 //! The maximum dimensionality of the AWH coordinate.
  61 static const int c_biasMaxNumDim = 4;
  62
  63 //! A real vector in AWH coordinate space.
  64 typedef double awh_dvec[c_biasMaxNumDim];
  65
  66 //! An integer vector in AWH coordinate space.
  67 typedef int awh_ivec[c_biasMaxNumDim];
  68
  69 /*! \internal \brief Constant parameters for each dimension of the coordinate.
  70  */
  71 struct DimParams
  72 {
  73     /*! \brief
  74      * Constructor.
  75      *
  76      * \param[in] conversionFactor  Conversion factor from user coordinate units to bias internal units (=DEG2RAD for angles).
  77      * \param[in] forceConstant     The harmonic force constant.
  78      * \param[in] beta              1/(k_B T).
  79      */
  80     DimParams(double conversionFactor,
  81               double forceConstant,
  82               double beta) :
  83         k(forceConstant),
  84         betak(beta*forceConstant),
  85         userCoordUnitsToInternal(conversionFactor)
  86     {
  87     }
  88
  89     /*! \brief Convert internal coordinate units to external, user coordinate units.
  90      *
  91      * \param[in] value               Value to convert.
  92      * \returns the converted value.
  93      */
  94     double scaleInternalToUserInput(double value) const
  95     {
  96         return value/userCoordUnitsToInternal;
  97     }
  98
  99     /*! \brief Convert external, user coordinate units to internal coordinate units.
 100      *
 101      * \param[in] value               Value to convert.
 102      * \returns the converted value.
 103      */
 104     double scaleUserInputToInternal(double value) const
 105     {
 106         return value*userCoordUnitsToInternal;
 107     }
 108
 109     const double k;                        /**< Force constant (kJ/mol/nm^2) for each coordinate dimension. */
 110     const double betak;                    /**< Inverse variance (1/nm^2) for each coordinate dimension. */
 111     const double userCoordUnitsToInternal; /**< Conversion factor coordinate units. */
 112 };
 113
 114 }      // namespace gmx
 115
 116 #endif /* GMX_AWH_DIMPARAMS_H */