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38 * Implements the Awh class.
40 * \author Viveca Lindahl
41 * \author Berk Hess <hess@kth.se>
42 * \author Magnus Lundborg
58 #include "gromacs/fileio/enxio.h"
59 #include "gromacs/gmxlib/network.h"
60 #include "gromacs/math/units.h"
61 #include "gromacs/mdrunutility/multisim.h"
62 #include "gromacs/mdtypes/awh_history.h"
63 #include "gromacs/mdtypes/awh_params.h"
64 #include "gromacs/mdtypes/commrec.h"
65 #include "gromacs/mdtypes/forceoutput.h"
66 #include "gromacs/mdtypes/inputrec.h"
67 #include "gromacs/mdtypes/pull_params.h"
68 #include "gromacs/mdtypes/state.h"
69 #include "gromacs/pbcutil/pbc.h"
70 #include "gromacs/pulling/pull.h"
71 #include "gromacs/timing/wallcycle.h"
72 #include "gromacs/trajectory/energyframe.h"
73 #include "gromacs/utility/arrayref.h"
74 #include "gromacs/utility/exceptions.h"
75 #include "gromacs/utility/gmxassert.h"
76 #include "gromacs/utility/pleasecite.h"
79 #include "biassharing.h"
80 #include "correlationgrid.h"
81 #include "pointstate.h"
87 * \brief A bias and its coupling to the system.
89 * This struct is used to separate the bias machinery in the Bias class,
90 * which should be independent from the reaction coordinate, from the
91 * obtaining of the reaction coordinate values and passing the computed forces.
92 * Currently the AWH method couples to the system by mapping each
93 * AWH bias to a pull coordinate. This can easily be generalized here.
95 struct BiasCoupledToSystem
97 /*! \brief Constructor, couple a bias to a set of pull coordinates.
99 * \param[in] bias The bias.
100 * \param[in] pullCoordIndex The pull coordinate indices.
102 BiasCoupledToSystem(Bias bias, const std::vector<int>& pullCoordIndex);
104 Bias bias_; /**< The bias. */
105 const std::vector<int> pullCoordIndex_; /**< The pull coordinates this bias acts on. */
107 /* Here AWH can be extended to work on other coordinates than pull. */
110 /*! \brief Checks whether any dimension uses pulling as a coordinate provider.
112 * \param[in] awhBiasParams The bias params to check.
113 * \returns true if any dimension of the bias is linked to pulling.
115 static bool anyDimUsesPull(const AwhBiasParams& awhBiasParams)
117 for (int d = 0; d < awhBiasParams.ndim; d++)
119 const AwhDimParams& awhDimParams = awhBiasParams.dimParams[d];
120 if (awhDimParams.eCoordProvider == eawhcoordproviderPULL)
128 /*! \brief Checks whether any dimension uses pulling as a coordinate provider.
130 * \param[in] awhParams The AWH params to check.
131 * \returns true if any dimension of awh is linked to pulling.
133 static bool anyDimUsesPull(const AwhParams& awhParams)
135 for (int k = 0; k < awhParams.numBias; k++)
137 const AwhBiasParams& awhBiasParams = awhParams.awhBiasParams[k];
138 if (anyDimUsesPull(awhBiasParams))
146 /*! \brief Checks whether any dimension uses pulling as a coordinate provider.
148 * \param[in] biasCoupledToSystem The AWH biases to check.
149 * \returns true if any dimension of the provided biases is linked to pulling.
151 static bool anyDimUsesPull(const ArrayRef<BiasCoupledToSystem> biasCoupledToSystem)
153 for (const auto& biasCts : biasCoupledToSystem)
155 if (!biasCts.pullCoordIndex_.empty())
163 BiasCoupledToSystem::BiasCoupledToSystem(Bias bias, const std::vector<int>& pullCoordIndex) :
164 bias_(std::move(bias)),
165 pullCoordIndex_(pullCoordIndex)
167 /* We already checked for this in grompp, but check again here. */
169 static_cast<size_t>(bias_.ndim()) == pullCoordIndex_.size() + bias_.hasFepLambdaDimension() ? 1 : 0,
170 "The bias dimensionality should match the number of pull and lambda coordinates.");
173 Awh::Awh(FILE* fplog,
174 const t_inputrec& inputRecord,
175 const t_commrec* commRecord,
176 const gmx_multisim_t* multiSimRecord,
177 const AwhParams& awhParams,
178 const std::string& biasInitFilename,
180 int numFepLambdaStates,
181 int fepLambdaState) :
182 seed_(awhParams.seed),
183 nstout_(awhParams.nstOut),
184 commRecord_(commRecord),
185 multiSimRecord_(multiSimRecord),
188 numFepLambdaStates_(numFepLambdaStates),
189 fepLambdaState_(fepLambdaState)
191 if (anyDimUsesPull(awhParams))
193 GMX_RELEASE_ASSERT(inputRecord.pull != nullptr, "With AWH we should have pull parameters");
194 GMX_RELEASE_ASSERT(pull_work != nullptr,
195 "With AWH pull should be initialized before initializing AWH");
198 if (fplog != nullptr)
200 please_cite(fplog, "Lindahl2014");
203 if (haveBiasSharingWithinSimulation(awhParams))
205 /* This has likely been checked by grompp, but throw anyhow. */
207 InvalidInputError("Biases within a simulation are shared, currently sharing of "
208 "biases is only supported between simulations"));
211 int numSharingSimulations = 1;
212 if (awhParams.shareBiasMultisim && isMultiSim(multiSimRecord_))
214 numSharingSimulations = multiSimRecord_->numSimulations_;
217 /* Initialize all the biases */
218 const double beta = 1 / (BOLTZ * inputRecord.opts.ref_t[0]);
219 for (int k = 0; k < awhParams.numBias; k++)
221 const AwhBiasParams& awhBiasParams = awhParams.awhBiasParams[k];
223 std::vector<int> pullCoordIndex;
224 std::vector<DimParams> dimParams;
225 for (int d = 0; d < awhBiasParams.ndim; d++)
227 const AwhDimParams& awhDimParams = awhBiasParams.dimParams[d];
228 if (awhDimParams.eCoordProvider != eawhcoordproviderPULL
229 && awhDimParams.eCoordProvider != eawhcoordproviderFREE_ENERGY_LAMBDA)
232 InvalidInputError("Currently only the pull code and lambda are supported "
233 "as coordinate providers"));
235 if (awhDimParams.eCoordProvider == eawhcoordproviderPULL)
237 const t_pull_coord& pullCoord = inputRecord.pull->coord[awhDimParams.coordIndex];
238 if (pullCoord.eGeom == epullgDIRPBC)
240 GMX_THROW(InvalidInputError(
241 "Pull geometry 'direction-periodic' is not supported by AWH"));
243 double conversionFactor = pull_coordinate_is_angletype(&pullCoord) ? DEG2RAD : 1;
244 pullCoordIndex.push_back(awhDimParams.coordIndex);
245 dimParams.push_back(DimParams::pullDimParams(conversionFactor,
246 awhDimParams.forceConstant, beta));
250 dimParams.push_back(DimParams::fepLambdaDimParams(numFepLambdaStates_, beta));
254 /* Construct the bias and couple it to the system. */
255 Bias::ThisRankWillDoIO thisRankWillDoIO =
256 (MASTER(commRecord_) ? Bias::ThisRankWillDoIO::Yes : Bias::ThisRankWillDoIO::No);
257 biasCoupledToSystem_.emplace_back(
258 Bias(k, awhParams, awhParams.awhBiasParams[k], dimParams, beta, inputRecord.delta_t,
259 numSharingSimulations, biasInitFilename, thisRankWillDoIO),
262 biasCoupledToSystem_.back().bias_.printInitializationToLog(fplog);
265 /* Need to register the AWH coordinates to be allowed to apply forces to the pull coordinates. */
266 registerAwhWithPull(awhParams, pull_);
268 if (numSharingSimulations > 1 && MASTER(commRecord_))
270 std::vector<size_t> pointSize;
271 for (auto const& biasCts : biasCoupledToSystem_)
273 pointSize.push_back(biasCts.bias_.state().points().size());
275 /* Ensure that the shared biased are compatible between simulations */
276 biasesAreCompatibleForSharingBetweenSimulations(awhParams, pointSize, multiSimRecord_);
280 Awh::~Awh() = default;
282 bool Awh::isOutputStep(int64_t step) const
284 return (nstout_ > 0 && step % nstout_ == 0);
287 real Awh::applyBiasForcesAndUpdateBias(PbcType pbcType,
289 ArrayRef<const double> neighborLambdaEnergies,
290 ArrayRef<const double> neighborLambdaDhdl,
292 gmx::ForceWithVirial* forceWithVirial,
295 gmx_wallcycle* wallcycle,
298 if (anyDimUsesPull(biasCoupledToSystem_))
300 GMX_ASSERT(forceWithVirial, "Need a valid ForceWithVirial object");
303 wallcycle_start(wallcycle, ewcAWH);
306 set_pbc(&pbc, pbcType, box);
308 /* During the AWH update the potential can instantaneously jump due to either
309 an bias update or moving the umbrella. The jumps are kept track of and
310 subtracted from the potential in order to get a useful conserved energy quantity. */
311 double awhPotential = potentialOffset_;
313 for (auto& biasCts : biasCoupledToSystem_)
315 /* Update the AWH coordinate values with those of the corresponding
318 awh_dvec coordValue = { 0, 0, 0, 0 };
319 int numLambdaDimsCounted = 0;
320 for (int d = 0; d < biasCts.bias_.ndim(); d++)
322 if (biasCts.bias_.dimParams()[d].isPullDimension())
324 coordValue[d] = get_pull_coord_value(
325 pull_, biasCts.pullCoordIndex_[d - numLambdaDimsCounted], &pbc);
329 coordValue[d] = fepLambdaState_;
330 numLambdaDimsCounted += 1;
334 /* Perform an AWH biasing step: this means, at regular intervals,
335 * sampling observables based on the input pull coordinate value,
336 * setting the bias force and/or updating the AWH bias state.
338 double biasPotential;
339 double biasPotentialJump;
340 /* Note: In the near future this call will be split in calls
341 * to supports bias sharing within a single simulation.
343 gmx::ArrayRef<const double> biasForce = biasCts.bias_.calcForceAndUpdateBias(
344 coordValue, neighborLambdaEnergies, neighborLambdaDhdl, &biasPotential,
345 &biasPotentialJump, commRecord_, multiSimRecord_, t, step, seed_, fplog);
347 awhPotential += biasPotential;
349 /* Keep track of the total potential shift needed to remove the potential jumps. */
350 potentialOffset_ -= biasPotentialJump;
352 /* Communicate the bias force to the pull struct.
353 * The bias potential is returned at the end of this function,
354 * so that it can be added externally to the correct energy data block.
356 numLambdaDimsCounted = 0;
357 for (int d = 0; d < biasCts.bias_.ndim(); d++)
359 if (biasCts.bias_.dimParams()[d].isPullDimension())
361 apply_external_pull_coord_force(pull_, biasCts.pullCoordIndex_[d - numLambdaDimsCounted],
362 biasForce[d], masses, forceWithVirial);
366 int umbrellaGridpointIndex = biasCts.bias_.state().coordState().umbrellaGridpoint();
367 fepLambdaState_ = biasCts.bias_.getGridCoordValue(umbrellaGridpointIndex)[d];
368 numLambdaDimsCounted += 1;
372 if (isOutputStep(step))
374 /* We might have skipped updates for part of the grid points.
375 * Ensure all points are updated before writing out their data.
377 biasCts.bias_.doSkippedUpdatesForAllPoints();
381 wallcycle_stop(wallcycle, ewcAWH);
383 return MASTER(commRecord_) ? static_cast<real>(awhPotential) : 0;
386 std::shared_ptr<AwhHistory> Awh::initHistoryFromState() const
388 if (MASTER(commRecord_))
390 std::shared_ptr<AwhHistory> awhHistory(new AwhHistory);
391 awhHistory->bias.clear();
392 awhHistory->bias.resize(biasCoupledToSystem_.size());
394 for (size_t k = 0; k < awhHistory->bias.size(); k++)
396 biasCoupledToSystem_[k].bias_.initHistoryFromState(&awhHistory->bias[k]);
403 /* Return an empty pointer */
404 return std::shared_ptr<AwhHistory>();
408 void Awh::restoreStateFromHistory(const AwhHistory* awhHistory)
410 /* Restore the history to the current state */
411 if (MASTER(commRecord_))
413 GMX_RELEASE_ASSERT(awhHistory != nullptr,
414 "The master rank should have a valid awhHistory when restoring the "
415 "state from history.");
417 if (awhHistory->bias.size() != biasCoupledToSystem_.size())
419 GMX_THROW(InvalidInputError(
420 "AWH state and history contain different numbers of biases. Likely you "
421 "provided a checkpoint from a different simulation."));
424 potentialOffset_ = awhHistory->potentialOffset;
426 if (PAR(commRecord_))
428 gmx_bcast(sizeof(potentialOffset_), &potentialOffset_, commRecord_->mpi_comm_mygroup);
431 for (size_t k = 0; k < biasCoupledToSystem_.size(); k++)
433 biasCoupledToSystem_[k].bias_.restoreStateFromHistory(
434 awhHistory ? &awhHistory->bias[k] : nullptr, commRecord_);
438 void Awh::updateHistory(AwhHistory* awhHistory) const
440 if (!MASTER(commRecord_))
445 /* This assert will also catch a non-master rank calling this function. */
446 GMX_RELEASE_ASSERT(awhHistory->bias.size() == biasCoupledToSystem_.size(),
447 "AWH state and history bias count should match");
449 awhHistory->potentialOffset = potentialOffset_;
451 for (size_t k = 0; k < awhHistory->bias.size(); k++)
453 biasCoupledToSystem_[k].bias_.updateHistory(&awhHistory->bias[k]);
457 const char* Awh::externalPotentialString()
462 void Awh::registerAwhWithPull(const AwhParams& awhParams, pull_t* pull_work)
464 GMX_RELEASE_ASSERT(!anyDimUsesPull(awhParams) || pull_work, "Need a valid pull object");
466 for (int k = 0; k < awhParams.numBias; k++)
468 const AwhBiasParams& biasParams = awhParams.awhBiasParams[k];
470 for (int d = 0; d < biasParams.ndim; d++)
472 if (biasParams.dimParams[d].eCoordProvider == eawhcoordproviderPULL)
474 register_external_pull_potential(pull_work, biasParams.dimParams[d].coordIndex,
475 Awh::externalPotentialString());
481 /* Fill the AWH data block of an energy frame with data (if there is any). */
482 void Awh::writeToEnergyFrame(int64_t step, t_enxframe* frame) const
484 GMX_ASSERT(MASTER(commRecord_), "writeToEnergyFrame should only be called on the master rank");
485 GMX_ASSERT(frame != nullptr, "Need a valid energy frame");
487 if (!isOutputStep(step))
489 /* This is not an AWH output step, don't write any AWH data */
493 /* Get the total number of energy subblocks that AWH needs */
494 int numSubblocks = 0;
495 for (auto& biasCoupledToSystem : biasCoupledToSystem_)
497 numSubblocks += biasCoupledToSystem.bias_.numEnergySubblocksToWrite();
499 GMX_ASSERT(numSubblocks > 0, "We should always have data to write");
501 /* Add 1 energy block */
502 add_blocks_enxframe(frame, frame->nblock + 1);
504 /* Take the block that was just added and set the number of subblocks. */
505 t_enxblock* awhEnergyBlock = &(frame->block[frame->nblock - 1]);
506 add_subblocks_enxblock(awhEnergyBlock, numSubblocks);
508 /* Claim it as an AWH block. */
509 awhEnergyBlock->id = enxAWH;
511 /* Transfer AWH data blocks to energy sub blocks */
512 int energySubblockCount = 0;
513 for (auto& biasCoupledToSystem : biasCoupledToSystem_)
515 energySubblockCount += biasCoupledToSystem.bias_.writeToEnergySubblocks(
516 &(awhEnergyBlock->sub[energySubblockCount]));
520 bool Awh::hasFepLambdaDimension() const
523 std::begin(biasCoupledToSystem_), std::end(biasCoupledToSystem_),
524 [](const auto& coupledBias) { return coupledBias.bias_.hasFepLambdaDimension(); });
527 bool Awh::needForeignEnergyDifferences(const int64_t step) const
529 /* If there is no FEP lambda dimension at all in any bias there will be no need for foreign
530 * energy differences */
531 if (!hasFepLambdaDimension())
539 /* Check whether the bias(es) that has/have a FEP lambda dimension should sample coordinates
540 * this step. Since the biases may have different sampleCoordStep it is necessary to check
541 * this combination. */
542 for (const auto& biasCts : biasCoupledToSystem_)
544 if (biasCts.bias_.hasFepLambdaDimension() && biasCts.bias_.isSampleCoordStep(step))
552 std::unique_ptr<Awh> prepareAwhModule(FILE* fplog,
553 const t_inputrec& inputRecord,
554 t_state* stateGlobal,
555 const t_commrec* commRecord,
556 const gmx_multisim_t* multiSimRecord,
557 const bool startingFromCheckpoint,
558 const bool usingShellParticles,
559 const std::string& biasInitFilename,
562 if (!inputRecord.bDoAwh)
566 if (usingShellParticles)
568 GMX_THROW(InvalidInputError("AWH biasing does not support shell particles."));
571 auto awh = std::make_unique<Awh>(
572 fplog, inputRecord, commRecord, multiSimRecord, *inputRecord.awhParams, biasInitFilename,
573 pull_work, inputRecord.fepvals->n_lambda, inputRecord.fepvals->init_fep_state);
575 if (startingFromCheckpoint)
577 // Restore the AWH history read from checkpoint
578 awh->restoreStateFromHistory(MASTER(commRecord) ? stateGlobal->awhHistory.get() : nullptr);
580 else if (MASTER(commRecord))
582 // Initialize the AWH history here
583 stateGlobal->awhHistory = awh->initHistoryFromState();