Euler

This integrator implements the explicit Euler method.

The algorithm propagates the positions in time as follows:

\[\vec{r}(t + \tau) = \vec{r}(t) + \tau \vec{v}(t)\]

where \(\tau\) is the timestep.

class halmd.mdsim.integrators.euler(args)

Construct Euler integrator for given system of particles

Parameters:

• args (table) – keyword arguments

• args.particle – instance of halmd.mdsim.particle

• args.box – instance of halmd.mdsim.box

• args.timestep (number) – integration time step (defaults to halmd.mdsim.clock.timestep)

• args.label (string) – instance label (default: ``particle.label``)

set_timestep(timestep)

Set integration time step in MD units.

Parameters:

timestep (number) – integration timestep

This method forwards to halmd.mdsim.clock.set_timestep(), to ensure that all integrators use an identical time step.

timestep

Integration time step in MD units.

label

Label of integrator instance.

disconnect()

Disconnect integrator from core and profiler.

integrate()

Calculate integration step

By default this function is connected to halmd.mdsim.core.on_integrate().

prepend_integrate()

Update forces if necessary and lock data.

By default this function is connected to halmd.mdsim.core.on_prepend_integrate().

append_integrate()

Release force lock.

By default this function is connected to halmd.mdsim.core.on_append_integrate().