Source code for blues.reporters

import logging
import sys
import time

import numpy as np
import parmed
import simtk.unit as unit
from mdtraj.reporters import HDF5Reporter
from mdtraj.utils import unitcell
from parmed import unit as u
from parmed.geometry import box_vectors_to_lengths_and_angles
from simtk.openmm import app

import blues._version
import blues.reporters
from blues.formats import *


def _check_mode(m, modes):
    """
    Check if the file has a read or write mode, otherwise throw an error.
    """
    if m not in modes:
        raise ValueError('This operation is only available when a file ' 'is open in mode="%s".' % m)


[docs]def addLoggingLevel(levelName, levelNum, methodName=None): """ Comprehensively adds a new logging level to the `logging` module and the currently configured logging class. `levelName` becomes an attribute of the `logging` module with the value `levelNum`. `methodName` becomes a convenience method for both `logging` itself and the class returned by `logging.getLoggerClass()` (usually just `logging.Logger`). If `methodName` is not specified, `levelName.lower()` is used. To avoid accidental clobberings of existing attributes, this method will raise an `AttributeError` if the level name is already an attribute of the `logging` module or if the method name is already present Parameters ---------- levelName : str The new level name to be added to the `logging` module. levelNum : int The level number indicated for the logging module. methodName : str, default=None The method to call on the logging module for the new level name. For example if provided 'trace', you would call `logging.trace()`. Example ------- >>> addLoggingLevel('TRACE', logging.DEBUG - 5) >>> logging.getLogger(__name__).setLevel("TRACE") >>> logging.getLogger(__name__).trace('that worked') >>> logging.trace('so did this') >>> logging.TRACE 5 """ if not methodName: methodName = levelName.lower() if hasattr(logging, levelName): logging.warn('{} already defined in logging module'.format(levelName)) if hasattr(logging, methodName): logging.warn('{} already defined in logging module'.format(methodName)) if hasattr(logging.getLoggerClass(), methodName): logging.warn('{} already defined in logger class'.format(methodName)) # This method was inspired by the answers to Stack Overflow post # http://stackoverflow.com/q/2183233/2988730, especially # http://stackoverflow.com/a/13638084/2988730 def logForLevel(self, message, *args, **kwargs): if self.isEnabledFor(levelNum): self._log(levelNum, message, args, **kwargs) def logToRoot(message, *args, **kwargs): logging.log(levelNum, message, *args, **kwargs) logging.addLevelName(levelNum, levelName) setattr(logging, levelName, levelNum) setattr(logging.getLoggerClass(), methodName, logForLevel) setattr(logging, methodName, logToRoot)
[docs]def init_logger(logger, level=logging.INFO, stream=True, outfname=time.strftime("blues-%Y%m%d-%H%M%S")): """Initialize the Logger module with the given logger_level and outfname. Parameters ---------- logger : logging.getLogger() The root logger object if it has been created already. level : logging.<LEVEL> Valid options for <LEVEL> would be DEBUG, INFO, WARNING, ERROR, CRITICAL. stream : bool, default = True If True, the logger will also stream information to sys.stdout as well as the output file. outfname : str, default = time.strftime("blues-%Y%m%d-%H%M%S") The output file path prefix to store the logged data. This will always write to a file with the extension `.log`. Returns ------- logger : logging.getLogger() The logging object with additional Handlers added. """ fmt = LoggerFormatter() if stream: # Stream to terminal stdout_handler = logging.StreamHandler(stream=sys.stdout) stdout_handler.setFormatter(fmt) logger.addHandler(stdout_handler) # Write to File if outfname: fh = logging.FileHandler(outfname + '.log') fh.setFormatter(fmt) logger.addHandler(fh) logger.addHandler(logging.NullHandler()) logger.setLevel(level) return logger
[docs]class ReporterConfig: """ Generates a set of custom/recommended reporters for BLUES simulations from YAML configuration. It can also be called externally without a YAML configuration file. Parameters ---------- outfname : str, Output filename prefix for files generated by the reporters. reporter_config : dict Dict of parameters for the md_reporters or ncmc_reporters. Valid keys for reporters are: `state`, `traj_netcdf`, `restart`, `progress`, and `stream`. All reporters except `stream` are extensions of the parmed.openmm.reporters. More below: - `state` : State data reporter for OpenMM simulations, but it is a little more generalized. Writes to a ``.ene`` file. For full list of parameters see `parmed.openmm.reporters.StateDataReporter`. - `traj_netcdf` : Customized AMBER NetCDF (``.nc``) format reporter - `restart` : Restart AMBER NetCDF (``.rst7``) format reporter - `progress` : Write to a file (``.prog``), the progress report of how many steps has been done, how fast the simulation is running, and how much time is left (similar to the mdinfo file in Amber). File is overwritten at each reportInterval. For full list of parameters see `parmed.openmm.reporters.ProgressReporter` - `stream` : Customized version of openmm.app.StateDataReporter.This will instead stream/print the information to the terminal as opposed to writing to a file. Takes the same parameters as the openmm.app.StateDataReporter logger : logging.Logger object Provide the root logger for printing information. Examples -------- This class is intended to be called internally from `blues.config.set_Reporters`. Below is an example to call this externally. >>> from blues.reporters import ReporterConfig >>> import logging >>> logger = logging.getLogger(__name__) >>> md_reporters = { "restart": { "reportInterval": 1000 }, "state" : { "reportInterval": 250 }, "stream": { "progress": true, "remainingTime": true, "reportInterval": 250, "speed": true, "step": true, "title": "md", "totalSteps": 10000}, "traj_netcdf": { "reportInterval": 250 } } >>> md_reporter_cfg = ReporterConfig(outfname='blues-test', md_reporters, logger) >>> md_reporters_list = md_reporter_cfg.makeReporters() """ def __init__(self, outfname, reporter_config, logger=None): self._outfname = outfname self._cfg = reporter_config self._logger = logger self.trajectory_interval = 0
[docs] def makeReporters(self): """ Returns a list of openmm Reporters based on the configuration at initialization of the class. """ Reporters = [] if 'state' in self._cfg.keys(): #Use outfname specified for reporter if 'outfname' in self._cfg['state']: outfname = self._cfg['state']['outfname'] else: #Default to top level outfname outfname = self._outfname state = parmed.openmm.reporters.StateDataReporter(outfname + '.ene', **self._cfg['state']) Reporters.append(state) if 'traj_netcdf' in self._cfg.keys(): if 'outfname' in self._cfg['traj_netcdf']: outfname = self._cfg['traj_netcdf']['outfname'] else: outfname = self._outfname #Store as an attribute for calculating time/frame if 'reportInterval' in self._cfg['traj_netcdf'].keys(): self.trajectory_interval = self._cfg['traj_netcdf']['reportInterval'] traj_netcdf = NetCDF4Reporter(outfname + '.nc', **self._cfg['traj_netcdf']) Reporters.append(traj_netcdf) if 'restart' in self._cfg.keys(): if 'outfname' in self._cfg['restart']: outfname = self._cfg['restart']['outfname'] else: outfname = self._outfname restart = parmed.openmm.reporters.RestartReporter(outfname + '.rst7', netcdf=True, **self._cfg['restart']) Reporters.append(restart) if 'progress' in self._cfg.keys(): if 'outfname' in self._cfg['progress']: outfname = self._cfg['progress']['outfname'] else: outfname = self._outfname progress = parmed.openmm.reporters.ProgressReporter(outfname + '.prog', **self._cfg['progress']) Reporters.append(progress) if 'stream' in self._cfg.keys(): if not self._logger: self._logger = logging.getLogger(__name__) stream = blues.reporters.BLUESStateDataReporter(self._logger, **self._cfg['stream']) Reporters.append(stream) return Reporters
###################### # REPORTERS # ######################
[docs]class BLUESHDF5Reporter(HDF5Reporter): """This is a subclass of the HDF5 class from mdtraj that handles reporting of the trajectory. HDF5Reporter stores a molecular dynamics trajectory in the HDF5 format. This object supports saving all kinds of information from the simulation -- more than any other trajectory format. In addition to all of the options, the topology of the system will also (of course) be stored in the file. All of the information is compressed, so the size of the file is not much different than DCD, despite the added flexibility. Parameters ---------- file : str, or HDF5TrajectoryFile Either an open HDF5TrajecoryFile object to write to, or a string specifying the filename of a new HDF5 file to save the trajectory to. title : str, String to specify the title of the HDF5 tables frame_indices : list, frame numbers for writing the trajectory reportInterval : int The interval (in time steps) at which to write frames. coordinates : bool Whether to write the coordinates to the file. time : bool Whether to write the current time to the file. cell : bool Whether to write the current unit cell dimensions to the file. potentialEnergy : bool Whether to write the potential energy to the file. kineticEnergy : bool Whether to write the kinetic energy to the file. temperature : bool Whether to write the instantaneous temperature to the file. velocities : bool Whether to write the velocities to the file. atomSubset : array_like, default=None Only write a subset of the atoms, with these (zero based) indices to the file. If None, *all* of the atoms will be written to disk. protocolWork : bool=False, Write the protocolWork for the alchemical process in the NCMC simulation alchemicalLambda : bool=False, Write the alchemicalLambda step for the alchemical process in the NCMC simulation. parameters : dict Dict of the simulation parameters. Useful for record keeping. environment : bool True will attempt to export your conda environment to JSON and store the information in the HDF5 file. Useful for record keeping. Notes ----- If you use the ``atomSubset`` option to write only a subset of the atoms to disk, the ``kineticEnergy``, ``potentialEnergy``, and ``temperature`` fields will not change. They will still refer to the energy and temperature of the *whole* system, and are not "subsetted" to only include the energy of your subsystem. """ @property def backend(self): return BLUESHDF5TrajectoryFile def __init__(self, file, reportInterval=1, title='NCMC Trajectory', coordinates=True, frame_indices=[], time=False, cell=True, temperature=False, potentialEnergy=False, kineticEnergy=False, velocities=False, atomSubset=None, protocolWork=True, alchemicalLambda=True, parameters=None, environment=True): super(BLUESHDF5Reporter, self).__init__(file, reportInterval, coordinates, time, cell, potentialEnergy, kineticEnergy, temperature, velocities, atomSubset) self._protocolWork = bool(protocolWork) self._alchemicalLambda = bool(alchemicalLambda) self._environment = bool(environment) self._title = title self._parameters = parameters self.frame_indices = frame_indices if self.frame_indices: #If simulation.currentStep = 1, store the frame from the previous step. # i.e. frame_indices=[1,100] will store the first and frame 100 self.frame_indices = [x - 1 for x in frame_indices]
[docs] def describeNextReport(self, simulation): """ Get information about the next report this object will generate. Parameters ---------- simulation : :class:`app.Simulation` The simulation to generate a report for Returns ------- nsteps, pos, vel, frc, ene : int, bool, bool, bool, bool nsteps is the number of steps until the next report pos, vel, frc, and ene are flags indicating whether positions, velocities, forces, and/or energies are needed from the Context """ #Monkeypatch to report at certain frame indices if self.frame_indices: if simulation.currentStep in self.frame_indices: steps = 1 else: steps = -1 if not self.frame_indices: steps_left = simulation.currentStep % self._reportInterval steps = self._reportInterval - steps_left return (steps, self._coordinates, self._velocities, False, self._needEnergy)
[docs] def report(self, simulation, state): """Generate a report. Parameters ---------- simulation : simtk.openmm.app.Simulation The Simulation to generate a report for state : simtk.openmm.State The current state of the simulation """ if not self._is_intialized: self._initialize(simulation) self._is_intialized = True self._checkForErrors(simulation, state) args = () kwargs = {} if self._coordinates: coordinates = state.getPositions(asNumpy=True)[self._atomSlice] coordinates = coordinates.value_in_unit(getattr(unit, self._traj_file.distance_unit)) args = (coordinates, ) if self._time: kwargs['time'] = state.getTime() if self._cell: vectors = state.getPeriodicBoxVectors(asNumpy=True) vectors = vectors.value_in_unit(getattr(unit, self._traj_file.distance_unit)) a, b, c, alpha, beta, gamma = unitcell.box_vectors_to_lengths_and_angles(*vectors) kwargs['cell_lengths'] = np.array([a, b, c]) kwargs['cell_angles'] = np.array([alpha, beta, gamma]) if self._potentialEnergy: kwargs['potentialEnergy'] = state.getPotentialEnergy() if self._kineticEnergy: kwargs['kineticEnergy'] = state.getKineticEnergy() if self._temperature: kwargs['temperature'] = 2 * state.getKineticEnergy() / (self._dof * unit.MOLAR_GAS_CONSTANT_R) if self._velocities: kwargs['velocities'] = state.getVelocities(asNumpy=True)[self._atomSlice, :] #add a portion like this to store things other than the protocol work if self._protocolWork: protocol_work = simulation.integrator.get_protocol_work(dimensionless=True) kwargs['protocolWork'] = np.array([protocol_work]) if self._alchemicalLambda: kwargs['alchemicalLambda'] = np.array([simulation.integrator.getGlobalVariableByName('lambda')]) if self._title: kwargs['title'] = self._title if self._parameters: kwargs['parameters'] = self._parameters if self._environment: kwargs['environment'] = self._environment self._traj_file.write(*args, **kwargs) # flush the file to disk. it might not be necessary to do this every # report, but this is the most proactive solution. We don't want to # accumulate a lot of data in memory only to find out, at the very # end of the run, that there wasn't enough space on disk to hold the # data. if hasattr(self._traj_file, 'flush'): self._traj_file.flush()
[docs]class BLUESStateDataReporter(app.StateDataReporter): """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. Inherited from `openmm.app.StateDataReporter` Parameters ---------- file : string or file The file to write to, specified as a file name or file-like object (Logger) reportInterval : int The interval (in time steps) at which to write frames frame_indices : list, frame numbers for writing the trajectory title : str, Text prefix for each line of the report. Used to distinguish between the NCMC and MD simulation reports. 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. protocolWork : bool=False, Write the protocolWork for the alchemical process in the NCMC simulation alchemicalLambda : bool=False, Write the alchemicalLambda step for the alchemical process in the NCMC simulation. """ def __init__(self, file, reportInterval=1, frame_indices=[], title='', 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='\t', systemMass=None, totalSteps=None, protocolWork=False, alchemicalLambda=False, currentIter=False): super(BLUESStateDataReporter, self).__init__( file, reportInterval, step, time, potentialEnergy, kineticEnergy, totalEnergy, temperature, volume, density, progress, remainingTime, speed, elapsedTime, separator, systemMass, totalSteps) self.log = self._out self.title = title self.frame_indices = frame_indices self._protocolWork, self._alchemicalLambda, self._currentIter = protocolWork, alchemicalLambda, currentIter if self.frame_indices: #If simulation.currentStep = 1, store the frame from the previous step. # i.e. frame_indices=[1,100] will store the first and frame 100 self.frame_indices = [x - 1 for x in frame_indices]
[docs] def describeNextReport(self, simulation): """ Get information about the next report this object will generate. Parameters ---------- simulation : :class:`app.Simulation` The simulation to generate a report for Returns ------- nsteps, pos, vel, frc, ene : int, bool, bool, bool, bool nsteps is the number of steps until the next report pos, vel, frc, and ene are flags indicating whether positions, velocities, forces, and/or energies are needed from the Context """ #Monkeypatch to report at certain frame indices if self.frame_indices: if simulation.currentStep in self.frame_indices: steps = 1 else: steps = -1 if not self.frame_indices: steps_left = simulation.currentStep % self._reportInterval steps = self._reportInterval - steps_left return (steps, self._needsPositions, self._needsVelocities, self._needsForces, self._needEnergy)
[docs] def report(self, simulation, state): """Generate a report. Parameters ---------- simulation : Simulation The Simulation to generate a report for state : State The current state of the simulation """ if not self._hasInitialized: self._initializeConstants(simulation) headers = self._constructHeaders() if hasattr(self.log, 'report'): self.log.info = self.log.report self.log.info('#"%s"' % ('"' + self._separator + '"').join(headers)) try: self._out.flush() except AttributeError: pass self._initialClockTime = time.time() self._initialSimulationTime = state.getTime() self._initialSteps = simulation.currentStep self._hasInitialized = True # Check for errors. self._checkForErrors(simulation, state) # Query for the values values = self._constructReportValues(simulation, state) # Write the values. if hasattr(self.log, 'report'): self.log.info = self.log.report self.log.info('%s: %s' % (self.title, self._separator.join(str(v) for v in values))) try: self._out.flush() except AttributeError: pass
def _constructReportValues(self, simulation, state): """Query the simulation for the current state of our observables of interest. Parameters ---------- simulation : Simulation The Simulation to generate a report for state : State The current state of the simulation Returns ------- values : list A list of values summarizing the current state of the simulation, to be printed or saved. Each element in the list corresponds to one of the columns in the resulting CSV file. """ values = [] box = state.getPeriodicBoxVectors() volume = box[0][0] * box[1][1] * box[2][2] clockTime = time.time() if self._currentIter: if not hasattr(simulation, 'currentIter'): simulation.currentIter = 0 values.append(simulation.currentIter) if self._progress: values.append('%.1f%%' % (100.0 * simulation.currentStep / self._totalSteps)) if self._step: values.append(simulation.currentStep) if self._time: values.append(state.getTime().value_in_unit(unit.picosecond)) #add a portion like this to store things other than the protocol work if self._alchemicalLambda: alchemicalLambda = simulation.integrator.getGlobalVariableByName('lambda') values.append(alchemicalLambda) if self._protocolWork: protocolWork = simulation.integrator.get_protocol_work(dimensionless=True) values.append(protocolWork) if self._potentialEnergy: values.append(state.getPotentialEnergy().value_in_unit(unit.kilojoules_per_mole)) if self._kineticEnergy: values.append(state.getKineticEnergy().value_in_unit(unit.kilojoules_per_mole)) if self._totalEnergy: values.append( (state.getKineticEnergy() + state.getPotentialEnergy()).value_in_unit(unit.kilojoules_per_mole)) if self._temperature: values.append( (2 * state.getKineticEnergy() / (self._dof * unit.MOLAR_GAS_CONSTANT_R)).value_in_unit(unit.kelvin)) if self._volume: values.append(volume.value_in_unit(unit.nanometer**3)) if self._density: values.append((self._totalMass / volume).value_in_unit(unit.gram / unit.item / unit.milliliter)) if self._speed: elapsedDays = (clockTime - self._initialClockTime) / 86400.0 elapsedNs = (state.getTime() - self._initialSimulationTime).value_in_unit(unit.nanosecond) if elapsedDays > 0.0: values.append('%.3g' % (elapsedNs / elapsedDays)) else: values.append('--') if self._elapsedTime: values.append(time.time() - self._initialClockTime) if self._remainingTime: elapsedSeconds = clockTime - self._initialClockTime elapsedSteps = simulation.currentStep - self._initialSteps if elapsedSteps == 0: value = '--' else: estimatedTotalSeconds = (self._totalSteps - self._initialSteps) * elapsedSeconds / elapsedSteps remainingSeconds = int(estimatedTotalSeconds - elapsedSeconds) remainingDays = remainingSeconds // 86400 remainingSeconds -= remainingDays * 86400 remainingHours = remainingSeconds // 3600 remainingSeconds -= remainingHours * 3600 remainingMinutes = remainingSeconds // 60 remainingSeconds -= remainingMinutes * 60 if remainingDays > 0: value = "%d:%d:%02d:%02d" % (remainingDays, remainingHours, remainingMinutes, remainingSeconds) elif remainingHours > 0: value = "%d:%02d:%02d" % (remainingHours, remainingMinutes, remainingSeconds) elif remainingMinutes > 0: value = "%d:%02d" % (remainingMinutes, remainingSeconds) else: value = "0:%02d" % remainingSeconds values.append(value) return values def _constructHeaders(self): """Construct the headers for the CSV output Returns ------- headers : list a list of strings giving the title of each observable being reported on. """ headers = [] if self._currentIter: headers.append('Iter') if self._progress: headers.append('Progress (%)') if self._step: headers.append('Step') if self._time: headers.append('Time (ps)') if self._alchemicalLambda: headers.append('alchemicalLambda') if self._protocolWork: headers.append('protocolWork') if self._potentialEnergy: headers.append('Potential Energy (kJ/mole)') if self._kineticEnergy: headers.append('Kinetic Energy (kJ/mole)') if self._totalEnergy: headers.append('Total Energy (kJ/mole)') if self._temperature: headers.append('Temperature (K)') if self._volume: headers.append('Box Volume (nm^3)') if self._density: headers.append('Density (g/mL)') if self._speed: headers.append('Speed (ns/day)') if self._elapsedTime: headers.append('Elapsed Time (s)') if self._remainingTime: headers.append('Time Remaining') return headers
[docs]class NetCDF4Reporter(parmed.openmm.reporters.NetCDFReporter): """ Class to read or write NetCDF trajectory files Inherited from `parmed.openmm.reporters.NetCDFReporter` Parameters ---------- file : str Name of the file to write the trajectory to reportInterval : int How frequently to write a frame to the trajectory frame_indices : list, frame numbers for writing the trajectory If this reporter is used for the NCMC simulation, 0.5 will report at the moveStep and -1 will record at the last frame. crds : bool=True Should we write coordinates to this trajectory? (Default True) vels : bool=False Should we write velocities to this trajectory? (Default False) frcs : bool=False Should we write forces to this trajectory? (Default False) protocolWork : bool=False, Write the protocolWork for the alchemical process in the NCMC simulation alchemicalLambda : bool=False, Write the alchemicalLambda step for the alchemical process in the NCMC simulation. """ def __init__(self, file, reportInterval=1, frame_indices=[], crds=True, vels=False, frcs=False, protocolWork=False, alchemicalLambda=False): """ Create a NetCDFReporter instance. """ super(NetCDF4Reporter, self).__init__(file, reportInterval, crds, vels, frcs) self.crds, self.vels, self.frcs, self.protocolWork, self.alchemicalLambda = crds, vels, frcs, protocolWork, alchemicalLambda self.frame_indices = frame_indices if self.frame_indices: #If simulation.currentStep = 1, store the frame from the previous step. # i.e. frame_indices=[1,100] will store the first and frame 100 self.frame_indices = [x - 1 for x in frame_indices]
[docs] def describeNextReport(self, simulation): """ Get information about the next report this object will generate. Parameters ---------- simulation : :class:`app.Simulation` The simulation to generate a report for Returns ------- nsteps, pos, vel, frc, ene : int, bool, bool, bool, bool nsteps is the number of steps until the next report pos, vel, frc, and ene are flags indicating whether positions, velocities, forces, and/or energies are needed from the Context """ #Monkeypatch to report at certain frame indices if self.frame_indices: if simulation.currentStep in self.frame_indices: steps = 1 else: steps = -1 if not self.frame_indices: steps_left = simulation.currentStep % self._reportInterval steps = self._reportInterval - steps_left return (steps, self.crds, self.vels, self.frcs, False)
[docs] def report(self, simulation, state): """Generate a report. Parameters ---------- simulation : :class:`app.Simulation` The Simulation to generate a report for state : :class:`mm.State` The current state of the simulation """ global VELUNIT, FRCUNIT if self.crds: crds = state.getPositions().value_in_unit(u.angstrom) if self.vels: vels = state.getVelocities().value_in_unit(VELUNIT) if self.frcs: frcs = state.getForces().value_in_unit(FRCUNIT) if self.protocolWork: protocolWork = simulation.integrator.get_protocol_work(dimensionless=True) if self.alchemicalLambda: alchemicalLambda = simulation.integrator.getGlobalVariableByName('lambda') if self._out is None: # This must be the first frame, so set up the trajectory now if self.crds: atom = len(crds) elif self.vels: atom = len(vels) elif self.frcs: atom = len(frcs) self.uses_pbc = simulation.topology.getUnitCellDimensions() is not None self._out = NetCDF4Traj.open_new( self.fname, atom, self.uses_pbc, self.crds, self.vels, self.frcs, title="ParmEd-created trajectory using OpenMM", protocolWork=self.protocolWork, alchemicalLambda=self.alchemicalLambda, ) if self.uses_pbc: vecs = state.getPeriodicBoxVectors() lengths, angles = box_vectors_to_lengths_and_angles(*vecs) self._out.add_cell_lengths_angles(lengths.value_in_unit(u.angstrom), angles.value_in_unit(u.degree)) # Add the coordinates, velocities, and/or forces as needed if self.crds: self._out.add_coordinates(crds) if self.vels: # The velocities get scaled right before writing self._out.add_velocities(vels) if self.frcs: self._out.add_forces(frcs) if self.protocolWork: self._out.add_protocolWork(protocolWork) if self.alchemicalLambda: self._out.add_alchemicalLambda(alchemicalLambda) # Now it's time to add the time. self._out.add_time(state.getTime().value_in_unit(u.picosecond))