Package etomica.data.meter

Class MeterWidomInsertion

java.lang.Object

etomica.data.DataSourceScalar

etomica.data.meter.MeterWidomInsertion

All Implemented Interfaces:

IDataSource

public class MeterWidomInsertion
extends DataSourceScalar

Meter to measure the chemical potential (as its exponent: exp(-mu/kT)) of a species via the Widom insertion method. Call to getDataAsScalar returns a Widom-insertion average (i.e., sum of exp(-energy/kT) using a configurable number of insertion trials) for a molecule of the desired species in the given box in its current configuration. It is expected that repeated calls will be averaged to give an overall insertion average for many configurations of the box.
Meter can be configured to measure the residual chemical potential -- above the ideal-gas value -- or the full chemical potential. If not configured for the residual chemical potential, the insertion average will be multiplied by the species number density in the box in its current configuration. Default behavior will give residual chemical potential. The actual chemical potential can be calculated as -kT ln() where x is the value returned by getDataAsScalar.

Field Summary

Fields

Modifier and Type	Field	Description
protected Box	box
protected RandomPositionSource	positionSource
protected double	pressure
protected double	temperature

Fields inherited from class etomica.data.DataSourceScalar

data, dataInfo, tag

Constructor Summary

Constructors

Constructor	Description
MeterWidomInsertion(Space space, IRandom random)

Method Summary

Modifier and Type	Method	Description
double	getDataAsScalar()	Performs a Widom insertion average, doing nInsert insertion attempts Temperature used to get exp(-uTest/kT) is that of the integrator for the box
IntegratorBox	getIntegrator()	Returns the integrator associated with this class.
int	getNInsert()	Accessor to number of Widom insertions attempted with each call to currentValue
RandomPositionSource	getPositionSource()	Returns the RandomPositionSource used by this meter.
ISpecies	getSpecies()	Accessor for the species for which chemical potential is evaluated
boolean	isResidual()	Accessor for flag specifying if full or residual chemical potential is computed
void	setBox(Box newBox)
void	setEnergyMeter(MeterPotentialEnergy newEnergyMeter)
void	setIntegrator(IntegratorBox newIntegrator)	Sets the integrator associated with this class.
void	setNInsert(int n)	Number of Widom insertions attempted with each call to currentValue
void	setPositionSource(RandomPositionSource newPositionSource)	Sets a new RandomPositionSource for this meter to use.
void	setPressure(double newPressure)
void	setResidual(boolean b)	Sets flag specifying if full or residual chemical potential is computed Default is true (only residual is computed)
void	setSpecies(ISpecies s)	Sets the species, takes a prototype molecule, and gets handle to appropriate species agent in box
void	setTemperature(double newTemperature)

Methods inherited from class etomica.data.DataSourceScalar

getData, getDataDouble, getDataInfo, getTag

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

positionSource

protected RandomPositionSource positionSource

box

protected Box box

temperature

protected double temperature

pressure

protected double pressure

Constructor Detail

MeterWidomInsertion

public MeterWidomInsertion(Space space,
                           IRandom random)

Method Detail

setResidual

public void setResidual(boolean b)

Sets flag specifying if full or residual chemical potential is computed Default is true (only residual is computed)

isResidual

public boolean isResidual()

Accessor for flag specifying if full or residual chemical potential is computed

setSpecies

public void setSpecies(ISpecies s)

Sets the species, takes a prototype molecule, and gets handle to appropriate species agent in box

getSpecies

public ISpecies getSpecies()

Accessor for the species for which chemical potential is evaluated

setNInsert

public void setNInsert(int n)

Number of Widom insertions attempted with each call to currentValue

getNInsert

public int getNInsert()

Accessor to number of Widom insertions attempted with each call to currentValue

setPressure

public void setPressure(double newPressure)

getDataAsScalar

public double getDataAsScalar()

Performs a Widom insertion average, doing nInsert insertion attempts Temperature used to get exp(-uTest/kT) is that of the integrator for the box

Specified by:

getDataAsScalar in class DataSourceScalar

Returns:

the sum of exp(-uTest/kT)/nInsert, multiplied by V/N if residual is false

getIntegrator

public IntegratorBox getIntegrator()

Returns the integrator associated with this class. The box, potentialMaster and temperature are taken from the integrator.

setIntegrator

public void setIntegrator(IntegratorBox newIntegrator)

Sets the integrator associated with this class. The box, potentialMaster and temperature are taken from the integrator. Alternatively, you can set the temperature, box and energy meter separately.

setEnergyMeter

public void setEnergyMeter(MeterPotentialEnergy newEnergyMeter)

setBox

public void setBox(Box newBox)

setTemperature

public void setTemperature(double newTemperature)

setPositionSource

public void setPositionSource(RandomPositionSource newPositionSource)

Sets a new RandomPositionSource for this meter to use. By default, a position source is used which assumes rectangular boundaries.

getPositionSource

public RandomPositionSource getPositionSource()

Returns the RandomPositionSource used by this meter.