Package ffx.openmm

Class VariableVerletIntegrator

java.lang.Object

ffx.openmm.Integrator

ffx.openmm.VariableVerletIntegrator

public class VariableVerletIntegrator
extends Integrator

This class implements a Verlet integrator with variable time stepping. The integrator automatically adjusts the step size to maintain a specified error tolerance, making it suitable for systems with widely varying time scales.

Unlike the standard Verlet integrator which uses a fixed step size, this variable step size algorithm monitors the local truncation error and adjusts the step size accordingly. This can lead to more efficient integration for systems where different parts evolve on different time scales.

Field Summary

Fields inherited from class ffx.openmm.Integrator

pointer

Constructor Summary

Constructors

Constructor	Description
VariableVerletIntegrator(double errorTol)	Create a VariableVerletIntegrator.

Method Summary

Modifier and Type	Method	Description
void	destroy()	Destroy the integrator.
double	getErrorTolerance()	Get the error tolerance for adaptive step sizing.
double	getMaximumStepSize()	Get the maximum step size the integrator is allowed to use (in ps).
void	setErrorTolerance(double tol)	Set the error tolerance for adaptive step sizing.
void	setMaximumStepSize(double size)	Set the maximum step size the integrator is allowed to use (in ps).
void	step(int steps)	Advance a simulation through time by taking a series of time steps.
void	stepTo(double time)	Advance the simulation by integrating until a specified time is reached.

Methods inherited from class ffx.openmm.Integrator

getConstraintTolerance, getIntegrationForceGroups, getPointer, getStepSize, setConstraintTolerance, setIntegrationForceGroups, setPointer, setStepSize

Methods inherited from class java.lang.Object

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

Constructor Details

VariableVerletIntegrator

public VariableVerletIntegrator(double errorTol)

Create a VariableVerletIntegrator.

Parameters:

errorTol - The error tolerance for adaptive step sizing.

Method Details

destroy

public void destroy()

Destroy the integrator.

Specified by:

destroy in class Integrator

getErrorTolerance

public double getErrorTolerance()

Get the error tolerance for adaptive step sizing.

Returns:

The error tolerance.

getMaximumStepSize

public double getMaximumStepSize()

Get the maximum step size the integrator is allowed to use (in ps).

Returns:

The maximum step size.

setErrorTolerance

public void setErrorTolerance(double tol)

Set the error tolerance for adaptive step sizing.

Parameters:

tol - The error tolerance.

setMaximumStepSize

public void setMaximumStepSize(double size)

Set the maximum step size the integrator is allowed to use (in ps).

Parameters:

size - The maximum step size.

step

public void step(int steps)

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

Overrides:

step in class Integrator

Parameters:

steps - The number of time steps to take.

stepTo

public void stepTo(double time)

Advance the simulation by integrating until a specified time is reached.

Parameters:

time - The time to which the simulation should be advanced (in ps).