meld.comm

class meld.comm.MPICommunicator(n_atoms, n_replicas)

Class to handle communications between master and slaves using MPI.

Parameters:

• n_atoms – number of atoms
• n_replicas – number of replicas

Note

creating an MPI communicator will not actually initialize MPI. To do that, call initialize().

broadcast_alphas_to_slaves(alphas)

Send the alpha values to the slaves.

Parameters:alphas – a list of alpha values, one for each replica. The master node’s alpha value should be included in this list. The master node will always be at alpha=0.0 Returns:None

broadcast_states_for_energy_calc_to_slaves(states)

Broadcast states to all slaves. Send all results from this step to every slave so that we can calculate the energies and do replica exchange.

Parameters:states – a list of states Returns:None

broadcast_states_to_slaves(states)

Send a state to each slave.

Parameters:states – a list of states. The list of states should include the state for the master node. These are the states that will be simulated on each replica for each step. Returns:the state to run on the master node

exchange_states_for_energy_calc(state)

Exchange states between all processes.

Parameters:state – the state for this node Returns:a list of states from all nodes

gather_energies_from_slaves(energies_on_master)

Receive a list of energies from each slave.

Parameters:energies_on_master – a list of energies from the master Returns:a square matrix of every state on every replica to be used for replica exchange

gather_states_from_slaves(state_on_master)

Receive states from all slaves

Parameters:state_on_master – the state on the master after simulating Returns:A list of states, one from each replica. The returned states are the states after simulating.

initialize()

Initialize and start MPI

is_master()

Is this the master node?

Returns:True if we are the master, otherwise False

receive_alpha_from_master()

Receive alpha value from master node.

Returns:a floating point value for alpha in [0,1]

receive_state_from_master()

Get state to run for this step

Returns:the state to run for this step

receive_states_for_energy_calc_from_master()

Receive all states from master.

Returns:a list of states to calculate the energy of

send_energies_to_master(energies)

Send a list of energies to the master.

Parameters:energies – a list of energies to send to the master Returns:None

send_state_to_master(state)

Send state to master

Parameters:state – State to send to master. This is the state after simulating this step. Returns:None