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39 * Declares the HistogramSize class.
41 * The data members of this class keep track of global size and update related
42 * properties of the bias histogram and the evolution of the histogram size.
43 * Initially histogramSize_ (and thus the convergence rate) is controlled
44 * heuristically to get good initial estimates, i.e. increase the robustness
47 * \author Viveca Lindahl
48 * \author Berk Hess <hess@kth.se>
52 #ifndef GMX_AWH_HISTOGRAMSIZE_H
53 #define GMX_AWH_HISTOGRAMSIZE_H
59 #include "gromacs/math/vectypes.h"
60 #include "gromacs/utility/arrayref.h"
65 struct AwhBiasStateHistory;
71 * \brief Tracks global size related properties of the bias histogram.
73 * Tracks the number of updates and the histogram size.
74 * Also keep track of the stage (initial/final of the AWH method
75 * and printing warnings about covering.
77 * \note Histogram sizes are floating-point values, since the histogram uses weighted
78 * entries and we can assign a floating-point scaling factor when changing it.
83 /*! \brief Constructor.
85 * \param[in] awhBiasParams The Bias parameters from inputrec.
86 * \param[in] histogramSizeInitial The initial histogram size.
88 HistogramSize(const AwhBiasParams& awhBiasParams, double histogramSizeInitial);
92 * Returns the new size of the reference weight histogram in the initial stage.
94 * This function also takes care resetting the histogram used for covering checks
95 * and for exiting the initial stage.
97 * \param[in] params The bias parameters.
99 * \param[in] detectedCovering True if we detected that the sampling interval has been
100 * sufficiently covered. \param[in,out] weightsumCovering The weight sum for checking covering.
101 * \param[in,out] fplog Log file.
102 * \returns the new histogram size.
104 double newHistogramSizeInitialStage(const BiasParams& params,
106 bool detectedCovering,
107 ArrayRef<double> weightsumCovering,
112 * Return the new reference weight histogram size for the current update.
114 * This function also takes care of checking for covering in the initial stage.
116 * \param[in] params The bias parameters.
118 * \param[in] covered True if the sampling interval has been covered enough.
119 * \param[in] pointStates The state of the grid points.
120 * \param[in,out] weightsumCovering The weight sum for checking covering.
121 * \param[in,out] fplog Log file.
122 * \returns the new histogram size.
124 double newHistogramSize(const BiasParams& params,
127 const std::vector<PointState>& pointStates,
128 ArrayRef<double> weightsumCovering,
131 /*! \brief Restores the histogram size from history.
133 * \param[in] stateHistory The AWH bias state history.
135 void restoreFromHistory(const AwhBiasStateHistory& stateHistory);
137 /*! \brief Store the histogram size state in a history struct.
139 * \param[in,out] stateHistory The AWH bias state history.
141 void storeState(AwhBiasStateHistory* stateHistory) const;
143 /*! \brief Returns the number of updates since the start of the simulation.
145 int numUpdates() const { return numUpdates_; }
147 /*! \brief Increments the number of updates by 1.
149 void incrementNumUpdates() { numUpdates_ += 1; }
151 /*! \brief Returns the histogram size.
153 double histogramSize() const { return histogramSize_; }
155 /*! \brief Sets the histogram size.
157 * \param[in] histogramSize The new histogram size.
158 * \param[in] weightHistogramScalingFactor The factor to scale the weight by.
160 void setHistogramSize(double histogramSize, double weightHistogramScalingFactor);
162 /*! \brief Returns true if we are in the initial stage of the AWH method.
164 bool inInitialStage() const { return inInitialStage_; }
166 /*! \brief Returns The log of the current sample weight, scaled because of the histogram rescaling.
168 double logScaledSampleWeight() const { return logScaledSampleWeight_; }
171 int64_t numUpdates_; /**< The number of updates performed since the start of the simulation. */
173 /* The histogram size sets the update size and so controls the convergence rate of the free energy and bias. */
174 double histogramSize_; /**< Size of reference weight histogram. */
176 /* Values that control the evolution of the histogram size. */
177 bool inInitialStage_; /**< True if in the intial stage. */
178 bool equilibrateHistogram_; /**< True if samples are kept from accumulating until the sampled distribution is close enough to the target. */
179 double logScaledSampleWeight_; /**< The log of the current sample weight, scaled because of the histogram rescaling. */
180 double maxLogScaledSampleWeight_; /**< Maximum sample weight obtained for previous (smaller) histogram sizes. */
182 /* Bool to avoid printing multiple, not so useful, messages to log */
183 bool havePrintedAboutCovering_; /**< True if we have printed about covering to the log while equilibrateHistogram==true */
188 #endif /* GMX_AWH_HISTOGRAMSIZE_H */