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LangevinIntegrator Class Reference

This is an Integrator which simulates a System using Langevin dynamics. More...

#include <LangevinIntegrator.h>

+ Inheritance diagram for LangevinIntegrator:

Public Member Functions

 LangevinIntegrator (double temperature, double frictionCoeff, double stepSize)
 Create a LangevinIntegrator.
 
double getTemperature () const
 Get the temperature of the heat bath (in Kelvin).
 
void setTemperature (double temp)
 Set the temperature of the heat bath (in Kelvin).
 
double getFriction () const
 Get the friction coefficient which determines how strongly the system is coupled to the heat bath (in inverse ps).
 
void setFriction (double coeff)
 Set the friction coefficient which determines how strongly the system is coupled to the heat bath (in inverse ps).
 
int getRandomNumberSeed () const
 Get the random number seed.
 
void setRandomNumberSeed (int seed)
 Set the random number seed.
 
void step (int steps)
 Advance a simulation through time by taking a series of time steps.
 
- Public Member Functions inherited from Integrator
 Integrator ()
 
virtual ~Integrator ()
 
double getStepSize () const
 Get the size of each time step, in picoseconds.
 
void setStepSize (double size)
 Set the size of each time step, in picoseconds.
 
double getConstraintTolerance () const
 Get the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.
 
void setConstraintTolerance (double tol)
 Set the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.
 

Protected Member Functions

void initialize (ContextImpl &context)
 This will be called by the Context when it is created.
 
void cleanup ()
 This will be called by the Context when it is destroyed to let the Integrator do any necessary cleanup.
 
std::vector< std::string > getKernelNames ()
 Get the names of all Kernels used by this Integrator.
 
double computeKineticEnergy ()
 Compute the kinetic energy of the system at the current time.
 
- Protected Member Functions inherited from Integrator
virtual void stateChanged (State::DataType changed)
 This will be called by the Context when the user modifies aspects of the context state, such as positions, velocities, or parameters.
 

Additional Inherited Members

- Protected Attributes inherited from Integrator
ContextImplcontext
 
Contextowner
 

Detailed Description

This is an Integrator which simulates a System using Langevin dynamics.

Constructor & Destructor Documentation

LangevinIntegrator ( double  temperature,
double  frictionCoeff,
double  stepSize 
)

Create a LangevinIntegrator.

Parameters
temperaturethe temperature of the heat bath (in Kelvin)
frictionCoeffthe friction coefficient which couples the system to the heat bath (in inverse picoseconds)
stepSizethe step size with which to integrator the system (in picoseconds)

Member Function Documentation

void cleanup ( )
protectedvirtual

This will be called by the Context when it is destroyed to let the Integrator do any necessary cleanup.

It will also get called again if the application calls reinitialize() on the Context.

Reimplemented from Integrator.

double computeKineticEnergy ( )
protectedvirtual

Compute the kinetic energy of the system at the current time.

Implements Integrator.

double getFriction ( ) const
inline

Get the friction coefficient which determines how strongly the system is coupled to the heat bath (in inverse ps).

Returns
the friction coefficient, measured in 1/ps
std::vector<std::string> getKernelNames ( )
protectedvirtual

Get the names of all Kernels used by this Integrator.

Implements Integrator.

int getRandomNumberSeed ( ) const
inline

Get the random number seed.

See setRandomNumberSeed() for details.

double getTemperature ( ) const
inline

Get the temperature of the heat bath (in Kelvin).

Returns
the temperature of the heat bath, measured in Kelvin
void initialize ( ContextImpl context)
protectedvirtual

This will be called by the Context when it is created.

It informs the Integrator of what context it will be integrating, and gives it a chance to do any necessary initialization. It will also get called again if the application calls reinitialize() on the Context.

Implements Integrator.

void setFriction ( double  coeff)
inline

Set the friction coefficient which determines how strongly the system is coupled to the heat bath (in inverse ps).

Parameters
coeffthe friction coefficient, measured in 1/ps
void setRandomNumberSeed ( int  seed)
inline

Set the random number seed.

The precise meaning of this parameter is undefined, and is left up to each Platform to interpret in an appropriate way. It is guaranteed that if two simulations are run with different random number seeds, the sequence of random forces will be different. On the other hand, no guarantees are made about the behavior of simulations that use the same seed. In particular, Platforms are permitted to use non-deterministic algorithms which produce different results on successive runs, even if those runs were initialized identically.

void setTemperature ( double  temp)
inline

Set the temperature of the heat bath (in Kelvin).

Parameters
tempthe temperature of the heat bath, measured in Kelvin
void step ( int  steps)
virtual

Advance a simulation through time by taking a series of time steps.

Parameters
stepsthe number of time steps to take

Implements Integrator.


The documentation for this class was generated from the following file: