Detailed Description

Replica exchange Monte Carlo move using Gibbs sampling.

This class implements a rather general form of the algorithm for a replica exchange / parallel tempering move. The algorithm assumes that the Boltzmann weight W(X,p) for a system in configuration X depends upon some floating point parameter p in a manner that is described by an Perturbation object associated with the parent System. The ReplicaMove constructor requires a parent System as a parameter, and requires that the System has an associated Perturbation object when the ReplicaMove is constructed.

This move implements a version replica exchange that uses the Gibbs sampler technique to sample permutations in replica space from the corresponding distribution. The sampling is done by running a small (inexpensive) Markov chain Monte Carlo simulation of nSamling steps at every replica exchange step, at the end of which a permutation is obtained that is used to swap configurations between replicas. This implies that all configurations are permuted simultaneously (but there may be configurations which stay on the same processor).

The technique is described in detail in John D. Chodera and Michael R. Shirts, J. Chem. Phys. 135, 194110 (2011)

Definition at line 63 of file ReplicaMove.h.

#include <ReplicaMove.h>

Inheritance diagram for McMd::ReplicaMove:

Public Member Functions
	ReplicaMove (System &system)
	Constructor. More...

virtual	~ReplicaMove ()
	Destructor. More...

virtual void	readParameters (std::istream &in)
	Read parameters. More...

virtual void	loadParameters (Serializable::IArchive &ar)
	Load internal state from an archive. More...

virtual void	save (Serializable::OArchive &ar)
	Save internal state to an archive. More...

virtual bool	move ()
	Attempt, and accept or reject a replica exchange move. More...

long	interval () const
	Get interval (number of steps between successives attempts). More...

bool	isAtInterval (long counter) const
	Return true iff counter is a multiple of the interval. More...

void	notifyObservers (sendRecvPair partners)
	Notify observers of a successful replica exchange. More...

long	nAttempt ()
	Number of swap attempts. More...

long	nAccept ()
	Number of accepted swaps. More...

Public Member Functions inherited from Util::ParamComposite
	ParamComposite ()
	Constructor. More...

	ParamComposite (const ParamComposite &other)
	Copy constructor. More...

	ParamComposite (int capacity)
	Constructor. More...

virtual	~ParamComposite ()
	Virtual destructor. More...

void	resetParam ()
	Resets ParamComposite to its empty state. More...

virtual void	readParam (std::istream &in)
	Read the parameter file block. More...

virtual void	readParamOptional (std::istream &in)
	Read optional parameter file block. More...

virtual void	writeParam (std::ostream &out)
	Write all parameters to an output stream. More...

virtual void	load (Serializable::IArchive &ar)
	Load all parameters from an input archive. More...

virtual void	loadOptional (Serializable::IArchive &ar)
	Load an optional ParamComposite. More...

void	saveOptional (Serializable::OArchive &ar)
	Saves isActive flag, and then calls save() iff isActive is true. More...

void	readParamComposite (std::istream &in, ParamComposite &child, bool next=true)
	Add and read a required child ParamComposite. More...

void	readParamCompositeOptional (std::istream &in, ParamComposite &child, bool next=true)
	Add and attempt to read an optional child ParamComposite. More...

template<typename Type >
ScalarParam< Type > &	read (std::istream &in, const char *label, Type &value)
	Add and read a new required ScalarParam < Type > object. More...

template<typename Type >
ScalarParam< Type > &	readOptional (std::istream &in, const char *label, Type &value)
	Add and read a new optional ScalarParam < Type > object. More...

template<typename Type >
CArrayParam< Type > &	readCArray (std::istream &in, const char label, Type value, int n)
	Add and read a required C array parameter. More...

template<typename Type >
CArrayParam< Type > &	readOptionalCArray (std::istream &in, const char label, Type value, int n)
	Add and read an optional C array parameter. More...

template<typename Type >
DArrayParam< Type > &	readDArray (std::istream &in, const char *label, DArray< Type > &array, int n)
	Add and read a required DArray < Type > parameter. More...

template<typename Type >
DArrayParam< Type > &	readOptionalDArray (std::istream &in, const char *label, DArray< Type > &array, int n)
	Add and read an optional DArray < Type > parameter. More...

template<typename Type , int N>
FArrayParam< Type, N > &	readFArray (std::istream &in, const char *label, FArray< Type, N > &array)
	Add and read a required FArray < Type, N > array parameter. More...

template<typename Type , int N>
FArrayParam< Type, N > &	readOptionalFArray (std::istream &in, const char *label, FArray< Type, N > &array)
	Add and read an optional FArray < Type, N > array parameter. More...

template<typename Type >
CArray2DParam< Type > &	readCArray2D (std::istream &in, const char label, Type value, int m, int n, int np)
	Add and read a required CArray2DParam < Type > 2D C-array. More...

template<typename Type >
CArray2DParam< Type > &	readOptionalCArray2D (std::istream &in, const char label, Type value, int m, int n, int np)
	Add and read an optional CArray2DParam < Type > 2D C-array parameter. More...

template<typename Type >
DMatrixParam< Type > &	readDMatrix (std::istream &in, const char *label, DMatrix< Type > &matrix, int m, int n)
	Add and read a required DMatrix < Type > matrix parameter. More...

template<typename Type >
DMatrixParam< Type > &	readOptionalDMatrix (std::istream &in, const char *label, DMatrix< Type > &matrix, int m, int n)
	Add and read an optional DMatrix < Type > matrix parameter. More...

template<typename Type >
DSymmMatrixParam< Type > &	readDSymmMatrix (std::istream &in, const char *label, DMatrix< Type > &matrix, int n)
	Add and read a required symmetrix DMatrix. More...

template<typename Type >
DSymmMatrixParam< Type > &	readOptionalDSymmMatrix (std::istream &in, const char *label, DMatrix< Type > &matrix, int n)
	Add and read an optional DMatrix matrix parameter. More...

Begin &	readBegin (std::istream &in, const char *label, bool isRequired=true)
	Add and read a class label and opening bracket. More...

End &	readEnd (std::istream &in)
	Add and read the closing bracket. More...

Blank &	readBlank (std::istream &in)
	Add and read a new Blank object, representing a blank line. More...

void	loadParamComposite (Serializable::IArchive &ar, ParamComposite &child, bool next=true)
	Add and load a required child ParamComposite. More...

void	loadParamCompositeOptional (Serializable::IArchive &ar, ParamComposite &child, bool next=true)
	Add and load an optional child ParamComposite if isActive. More...

template<typename Type >
ScalarParam< Type > &	loadParameter (Serializable::IArchive &ar, const char *label, Type &value, bool isRequired)
	Add and load a new ScalarParam < Type > object. More...

template<typename Type >
ScalarParam< Type > &	loadParameter (Serializable::IArchive &ar, const char *label, Type &value)
	Add and load new required ScalarParam < Type > object. More...

template<typename Type >
CArrayParam< Type > &	loadCArray (Serializable::IArchive &ar, const char label, Type value, int n, bool isRequired)
	Add a C array parameter and load its elements. More...

template<typename Type >
CArrayParam< Type > &	loadCArray (Serializable::IArchive &ar, const char label, Type value, int n)
	Add and load a required CArrayParam< Type > array parameter. More...

template<typename Type >
DArrayParam< Type > &	loadDArray (Serializable::IArchive &ar, const char *label, DArray< Type > &array, int n, bool isRequired)
	Add an load a DArray < Type > array parameter. More...

template<typename Type >
DArrayParam< Type > &	loadDArray (Serializable::IArchive &ar, const char *label, DArray< Type > &array, int n)
	Add and load a required DArray< Type > array parameter. More...

template<typename Type , int N>
FArrayParam< Type, N > &	loadFArray (Serializable::IArchive &ar, const char *label, FArray< Type, N > &array, bool isRequired)
	Add and load an FArray < Type, N > fixed-size array parameter. More...

template<typename Type , int N>
FArrayParam< Type, N > &	loadFArray (Serializable::IArchive &ar, const char *label, FArray< Type, N > &array)
	Add and load a required FArray < Type > array parameter. More...

template<typename Type >
CArray2DParam< Type > &	loadCArray2D (Serializable::IArchive &ar, const char label, Type value, int m, int n, int np, bool isRequired)
	Add and load a CArray2DParam < Type > C 2D array parameter. More...

template<typename Type >
CArray2DParam< Type > &	loadCArray2D (Serializable::IArchive &ar, const char label, Type value, int m, int n, int np)
	Add and load a required < Type > matrix parameter. More...

template<typename Type >
DMatrixParam< Type > &	loadDMatrix (Serializable::IArchive &ar, const char *label, DMatrix< Type > &matrix, int m, int n, bool isRequired)
	Add and load a DMatrixParam < Type > matrix parameter. More...

template<typename Type >
DMatrixParam< Type > &	loadDMatrix (Serializable::IArchive &ar, const char *label, DMatrix< Type > &matrix, int m, int n)
	Add and load a required DMatrixParam < Type > matrix parameter. More...

template<typename Type >
DSymmMatrixParam< Type > &	loadDSymmMatrix (Serializable::IArchive &ar, const char *label, DMatrix< Type > &matrix, int n, bool isRequired)
	Add and load a symmetric DSymmMatrixParam < Type > matrix parameter. More...

template<typename Type >
DSymmMatrixParam< Type > &	loadDSymmMatrix (Serializable::IArchive &ar, const char *label, DMatrix< Type > &matrix, int n)
	Add and load a required DSymmMatrixParam < Type > matrix parameter. More...

void	addParamComposite (ParamComposite &child, bool next=true)
	Add a child ParamComposite object to the format array. More...

Begin &	addBegin (const char *label)
	Add a Begin object representing a class name and bracket. More...

End &	addEnd ()
	Add a closing bracket. More...

Blank &	addBlank ()
	Create and add a new Blank object, representing a blank line. More...

std::string	className () const
	Get class name string. More...

bool	isRequired () const
	Is this ParamComposite required in the input file? More...

bool	isActive () const
	Is this parameter active? More...

Public Member Functions inherited from Util::ParamComponent
virtual	~ParamComponent ()
	Destructor. More...

void	setIndent (const ParamComponent &parent, bool next=true)
	Set indent level. More...

std::string	indent () const
	Return indent string for this object (string of spaces). More...

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
	Serialize this ParamComponent as a string. More...

Public Member Functions inherited from Util::Serializable
virtual	~Serializable ()
	Destructor. More...

Public Member Functions inherited from Util::MpiFileIo
	MpiFileIo ()
	Constructor. More...

	MpiFileIo (const MpiFileIo &other)
	Copy constructor. More...

bool	isIoProcessor () const
	Can this processor do file I/O ? More...

void	setIoCommunicator (MPI::Intracomm &communicator)
	Set the communicator. More...

void	clearCommunicator ()
	Clear (nullify) the communicator. More...

bool	hasIoCommunicator () const
	Does this object have an associated MPI communicator? More...

MPI::Intracomm &	ioCommunicator () const
	Get the MPI communicator by reference. More...

Public Member Functions inherited from Util::Notifier< sendRecvPair >
void	registerObserver (Observer< sendRecvPair > &observer)
	Register an observer. More...

void	removeObserver (Observer< sendRecvPair > &observer)
	Remove an analyzer observer from the container list. More...

void	notifyObservers (const sendRecvPair &event)
	Notify the list of observers about an Event. More...

Protected Member Functions
System &	system ()
	Return the associated system by reference. More...

Protected Member Functions inherited from Util::ParamComposite
void	setClassName (const char *className)
	Set class name string. More...

void	setIsRequired (bool isRequired)
	Set or unset the isActive flag. More...

void	setIsActive (bool isActive)
	Set or unset the isActive flag. More...

void	setParent (ParamComponent &param, bool next=true)
	Set this to the parent of a child component. More...

void	addComponent (ParamComponent &param, bool isLeaf=true)
	Add a new ParamComponent object to the format array. More...

template<typename Type >
ScalarParam< Type > &	add (std::istream &in, const char *label, Type &value, bool isRequired=true)
	Add a new required ScalarParam < Type > object. More...

template<typename Type >
CArrayParam< Type > &	addCArray (std::istream &in, const char label, Type value, int n, bool isRequired=true)
	Add (but do not read) a required C array parameter. More...

template<typename Type >
DArrayParam< Type > &	addDArray (std::istream &in, const char *label, DArray< Type > &array, int n, bool isRequired=true)
	Add (but do not read) a DArray < Type > parameter. More...

template<typename Type , int N>
FArrayParam< Type, N > &	addFArray (std::istream &in, const char *label, FArray< Type, N > &array, bool isRequired=true)
	Add (but do not read) a FArray < Type, N > array parameter. More...

template<typename Type >
CArray2DParam< Type > &	addCArray2D (std::istream &in, const char label, Type value, int m, int n, int np, bool isRequired=true)
	Add (but do not read) a CArray2DParam < Type > 2D C-array. More...

template<typename Type >
DMatrixParam< Type > &	addDMatrix (std::istream &in, const char *label, DMatrix< Type > &matrix, int m, int n, bool isRequired=true)
	Add and read a required DMatrix < Type > matrix parameter. More...

Protected Member Functions inherited from Util::ParamComponent
	ParamComponent ()
	Constructor. More...

	ParamComponent (const ParamComponent &other)
	Copy constructor. More...

Additional Inherited Members
Public Types inherited from Util::Serializable
typedef BinaryFileOArchive	OArchive
	Type of output archive used by save method. More...

typedef BinaryFileIArchive	IArchive
	Type of input archive used by load method. More...

Static Public Member Functions inherited from Util::ParamComponent
static void	initStatic ()
	Initialize static echo member to false. More...

static void	setEcho (bool echo=true)
	Enable or disable echoing for all subclasses of ParamComponent. More...

static bool	echo ()
	Get echo parameter. More...

Constructor & Destructor Documentation

McMd::ReplicaMove::ReplicaMove ( System & system )

Constructor.

Definition at line 37 of file ReplicaMove.cpp.

References McMd::Simulation::communicator(), McMd::System::fileMaster(), McMd::Perturbation::getNParameters(), McMd::System::hasPerturbation(), Util::FileMaster::openOutputFile(), McMd::System::perturbation(), Util::ParamComposite::setClassName(), McMd::System::simulation(), and UTIL_THROW.

McMd::ReplicaMove::~ReplicaMove ( )

virtual

Destructor.

Definition at line 81 of file ReplicaMove.cpp.

Member Function Documentation

void McMd::ReplicaMove::readParameters ( std::istream & in )

virtual

Read parameters.

The parameter block takes the parameter interval, which sets the interval between successive replica exchange attempts.

At every replica exchange attempt, the permutation is sampled from a MCMC run of nSampling steps. Empirically, nSampling should be on the order of P^3 .. P^5, where P is the number of processors.

Parameters