# Integrator¶

class simtk.openmm.openmm.Integrator(*args, **kwargs)

An Integrator defines a method for simulating a System by integrating the equations of motion. This is an abstract class. Subclasses define particular integration methods.

Each Integrator object is bound to a particular Context which it integrates. This connection is specified by passing the Integrator as an argument to the constructor of the Context.

__init__(*args, **kwargs)

Methods

 __init__(*args, **kwargs) getConstraintTolerance((self) -> double) Get the distance tolerance within which constraints are maintained, as a fraction of the constrained distance. getStepSize((self) -> double) Get the size of each time step, in picoseconds. setConstraintTolerance(self, tol) Set the distance tolerance within which constraints are maintained, as a fraction of the constrained distance. setStepSize(self, size) Set the size of each time step, in picoseconds. step(self, steps) Advance a simulation through time by taking a series of time steps.
getStepSize(self) → double

Get the size of each time step, in picoseconds. If this integrator uses variable time steps, the size of the most recent step is returned.

Returns: the step size, measured in ps double
setStepSize(self, size)

Set the size of each time step, in picoseconds. If this integrator uses variable time steps, the effect of calling this method is undefined, and it may simply be ignored.

Parameters: size (double) – the step size, measured in ps
getConstraintTolerance(self) → double

Get the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.

setConstraintTolerance(self, tol)

Set the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.

step(self, steps)

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

Parameters: steps (int) – the number of time steps to take
__copy__(self) → Integrator