StateDataReporter

class openmm.app.statedatareporter.StateDataReporter(file, reportInterval, step=False, time=False, potentialEnergy=False, kineticEnergy=False, totalEnergy=False, temperature=False, volume=False, density=False, progress=False, remainingTime=False, speed=False, elapsedTime=False, separator=',', systemMass=None, totalSteps=None, append=False)

StateDataReporter outputs information about a simulation, such as energy and temperature, to a file.

To use it, create a StateDataReporter, then add it to the Simulation’s list of reporters. The set of data to write is configurable using boolean flags passed to the constructor. By default the data is written in comma-separated-value (CSV) format, but you can specify a different separator to use.

__init__(file, reportInterval, step=False, time=False, potentialEnergy=False, kineticEnergy=False, totalEnergy=False, temperature=False, volume=False, density=False, progress=False, remainingTime=False, speed=False, elapsedTime=False, separator=',', systemMass=None, totalSteps=None, append=False)

Create a StateDataReporter.

Parameters

• file (string or file) – The file to write to, specified as a file name or file object

• reportInterval (int) – The interval (in time steps) at which to write frames

• step (bool=False) – Whether to write the current step index to the file

• time (bool=False) – Whether to write the current time to the file

• potentialEnergy (bool=False) – Whether to write the potential energy to the file

• kineticEnergy (bool=False) – Whether to write the kinetic energy to the file

• totalEnergy (bool=False) – Whether to write the total energy to the file

• temperature (bool=False) – Whether to write the instantaneous temperature to the file

• volume (bool=False) – Whether to write the periodic box volume to the file

• density (bool=False) – Whether to write the system density to the file

• progress (bool=False) – Whether to write current progress (percent completion) to the file. If this is True, you must also specify totalSteps.

• remainingTime (bool=False) – Whether to write an estimate of the remaining clock time until completion to the file. If this is True, you must also specify totalSteps.

• speed (bool=False) – Whether to write an estimate of the simulation speed in ns/day to the file

• elapsedTime (bool=False) – Whether to write the elapsed time of the simulation in seconds to the file.

• separator (string=',') – The separator to use between columns in the file

• systemMass (mass=None) – The total mass to use for the system when reporting density. If this is None (the default), the system mass is computed by summing the masses of all particles. This parameter is useful when the particle masses do not reflect their actual physical mass, such as when some particles have had their masses set to 0 to immobilize them.

• totalSteps (int=None) – The total number of steps that will be included in the simulation. This is required if either progress or remainingTime is set to True, and defines how many steps will indicate 100% completion.

• append (bool=False) – If true, append to an existing file. This has two effects. First, the file is opened in append mode. Second, the header line is not written, since there is assumed to already be a header line at the start of the file.

Methods

__init__(file, reportInterval[, step, time, …])	Create a StateDataReporter.
describeNextReport(simulation)	Get information about the next report this object will generate.
report(simulation, state)	Generate a report.

describeNextReport(simulation)

Get information about the next report this object will generate.

Parameters

simulation (Simulation) – The Simulation to generate a report for

Returns

A five element tuple. The first element is the number of steps until the next report. The remaining elements specify whether that report will require positions, velocities, forces, and energies respectively.

Return type

tuple

report(simulation, state)

Generate a report.

Parameters

• simulation (Simulation) – The Simulation to generate a report for

• state (State) – The current state of the simulation