"""bundletrajectory - a module for I/O from large MD simulations.
The BundleTrajectory class writes trajectory into a directory with the
following structure, except we now use JSON instead of pickle,
so this text needs updating::
filename.bundle (dir)
metadata.json Data about the file format, and about which
data is present.
frames The number of frames (ascii file)
F0 (dir) Frame number 0
smalldata.ulm Small data structures in a dictionary
(pbc, cell, ...)
numbers.ulm Atomic numbers
positions.ulm Positions
momenta.ulm Momenta
...
F1 (dir)
There is a folder for each frame, and the data is in the ASE Ulm format.
"""
import os
import sys
import shutil
import time
from pathlib import Path
import numpy as np
from ase import Atoms
# The system json module causes memory leaks! Use ase's own.
# import json
from ase.io import jsonio
from ase.io.ulm import open as ulmopen
from ase.parallel import paropen, world, barrier
from ase.calculators.singlepoint import (SinglePointCalculator,
PropertyNotImplementedError)
[docs]class BundleTrajectory:
"""Reads and writes atoms into a .bundle directory.
The BundleTrajectory is an alternative way of storing
trajectories, intended for large-scale molecular dynamics
simulations, where a single flat file becomes unwieldy. Instead,
the data is stored in directory, a 'bundle' (the name bundle is
inspired from bundles in Mac OS, which are really just directories
the user is supposed to think of as a single file-like unit).
Parameters:
filename:
The name of the directory. Preferably ending in .bundle.
mode (optional):
The file opening mode. 'r' means open for reading, 'w' for
writing and 'a' for appending. Default: 'r'. If opening in
write mode, and the filename already exists, the old file is
renamed to .bak (any old .bak file is deleted), except if the
existing file is empty.
atoms (optional):
The atoms that will be written. Can only be specified in
write or append mode. If not specified, the atoms must be
given as an argument to the .write() method instead.
backup=True:
Use backup=False to disable renaming of an existing file.
backend='ulm':
Request a backend. Currently only 'ulm' is supported.
Only honored when writing.
singleprecision=False:
Store floating point data in single precision (ulm backend only).
"""
slavelog = True # Log from all nodes
def __init__(self, filename, mode='r', atoms=None, backup=True,
backend='ulm', singleprecision=False):
self.state = 'constructing'
self.filename = filename
self.pre_observers = [] # callback functions before write is performed
self.post_observers = [] # callback functions after write is performed
self.master = world.rank == 0
self.extra_data = []
self.singleprecision = singleprecision
self._set_defaults()
if mode == 'r':
if atoms is not None:
raise ValueError('You cannot specify atoms in read mode.')
self._open_read()
elif mode == 'w':
self._open_write(atoms, backup, backend)
elif mode == 'a':
self._open_append(atoms)
else:
raise ValueError('Unknown mode: ' + str(mode))
def _set_defaults(self):
"Set default values for internal parameters."
self.version = 1
self.subtype = 'normal'
self.datatypes = {'positions': True,
'numbers': 'once',
'tags': 'once',
'masses': 'once',
'momenta': True,
'forces': True,
'energy': True,
'energies': False,
'stress': False,
'magmoms': True}
def _set_backend(self, backend):
"""Set the backed doing the actual I/O."""
if backend is not None:
self.backend_name = backend
if self.backend_name == 'ulm':
self.backend = UlmBundleBackend(self.master, self.singleprecision)
else:
raise NotImplementedError(
'This version of ASE cannot use BundleTrajectory '
'with backend "%s"' % self.backend_name)
[docs] def write(self, atoms=None):
"""Write the atoms to the file.
If the atoms argument is not given, the atoms object specified
when creating the trajectory object is used.
"""
# Check that we are in write mode
if self.state == 'prewrite':
self.state = 'write'
assert self.nframes == 0
elif self.state != 'write':
raise RuntimeError('Cannot write in ' + self.state + ' mode.')
if atoms is None:
atoms = self.atoms
for image in atoms.iterimages():
self._write_atoms(image)
def _write_atoms(self, atoms):
# OK, it is a real atoms object. Write it.
self._call_observers(self.pre_observers)
self.log('Beginning to write frame ' + str(self.nframes))
framedir = self._make_framedir(self.nframes)
# Check which data should be written the first time:
# Modify datatypes so any element of type 'once' becomes true
# for the first frame but false for subsequent frames.
datatypes = {}
for k, v in self.datatypes.items():
if v == 'once':
v = (self.nframes == 0)
datatypes[k] = v
# Write 'small' data structures. They are written jointly.
smalldata = {'pbc': atoms.get_pbc(),
'cell': atoms.get_cell(),
'natoms': atoms.get_global_number_of_atoms(),
'constraints': atoms.constraints}
if datatypes.get('energy'):
try:
smalldata['energy'] = atoms.get_potential_energy()
except (RuntimeError, PropertyNotImplementedError):
self.datatypes['energy'] = False
if datatypes.get('stress'):
try:
smalldata['stress'] = atoms.get_stress()
except PropertyNotImplementedError:
self.datatypes['stress'] = False
self.backend.write_small(framedir, smalldata)
# Write the large arrays.
if datatypes.get('positions'):
self.backend.write(framedir, 'positions', atoms.get_positions())
if datatypes.get('numbers'):
self.backend.write(framedir, 'numbers', atoms.get_atomic_numbers())
if datatypes.get('tags'):
if atoms.has('tags'):
self.backend.write(framedir, 'tags', atoms.get_tags())
else:
self.datatypes['tags'] = False
if datatypes.get('masses'):
if atoms.has('masses'):
self.backend.write(framedir, 'masses', atoms.get_masses())
else:
self.datatypes['masses'] = False
if datatypes.get('momenta'):
if atoms.has('momenta'):
self.backend.write(framedir, 'momenta', atoms.get_momenta())
else:
self.datatypes['momenta'] = False
if datatypes.get('magmoms'):
if atoms.has('initial_magmoms'):
self.backend.write(framedir, 'magmoms',
atoms.get_initial_magnetic_moments())
else:
self.datatypes['magmoms'] = False
if datatypes.get('forces'):
try:
x = atoms.get_forces()
except (RuntimeError, PropertyNotImplementedError):
self.datatypes['forces'] = False
else:
self.backend.write(framedir, 'forces', x)
del x
if datatypes.get('energies'):
try:
x = atoms.get_potential_energies()
except (RuntimeError, PropertyNotImplementedError):
self.datatypes['energies'] = False
else:
self.backend.write(framedir, 'energies', x)
del x
# Write any extra data
for (label, source, once) in self.extra_data:
if self.nframes == 0 or not once:
if source is not None:
x = source()
else:
x = atoms.get_array(label)
self.backend.write(framedir, label, x)
del x
if once:
self.datatypes[label] = 'once'
else:
self.datatypes[label] = True
# Finally, write metadata if it is the first frame
if self.nframes == 0:
metadata = {'datatypes': self.datatypes}
self._write_metadata(metadata)
self._write_nframes(self.nframes + 1)
self._call_observers(self.post_observers)
self.log('Done writing frame ' + str(self.nframes))
self.nframes += 1
[docs] def select_data(self, data, value):
"""Selects if a given data type should be written.
Data can be written in every frame (specify True), in the
first frame only (specify 'only') or not at all (specify
False). Not all data types support the 'only' keyword, if not
supported it is interpreted as True.
The following data types are supported, the letter in parenthesis
indicates the default:
positions (T), numbers (O), tags (O), masses (O), momenta (T),
forces (T), energy (T), energies (F), stress (F), magmoms (T)
If a given property is not present during the first write, it
will be not be saved at all.
"""
if value not in (True, False, 'once'):
raise ValueError('Unknown write mode')
if data not in self.datatypes:
raise ValueError('Unsupported data type: ' + data)
self.datatypes[data] = value
[docs] def close(self):
"Closes the trajectory."
self.state = 'closed'
lf = getattr(self, 'logfile', None)
self.backend.close(log=lf)
if lf is not None:
lf.close()
del self.logfile
[docs] def log(self, text):
"""Write to the log file in the bundle.
Logging is only possible in write/append mode.
This function is mainly for internal use, but can also be called by
the user.
"""
if not (self.master or self.slavelog):
return
text = time.asctime() + ': ' + text
if hasattr(self, 'logfile'):
# Logging enabled
if self.logfile is None:
# Logfile not yet open
try:
self.logdata.append(text)
except AttributeError:
self.logdata = [text]
else:
self.logfile.write(text + '\n')
self.logfile.flush()
else:
raise RuntimeError('Cannot write to log file in mode ' +
self.state)
# __getitem__ is the main reading method.
def __getitem__(self, n):
return self._read(n)
def _read(self, n):
"""Read an atoms object from the BundleTrajectory."""
if self.state != 'read':
raise IOError('Cannot read in %s mode' % (self.state,))
if n < 0:
n += self.nframes
if n < 0 or n >= self.nframes:
raise IndexError('Trajectory index %d out of range [0, %d['
% (n, self.nframes))
framedir = os.path.join(self.filename, 'F' + str(n))
framezero = os.path.join(self.filename, 'F0')
smalldata = self.backend.read_small(framedir)
data = {}
data['pbc'] = smalldata['pbc']
data['cell'] = smalldata['cell']
data['constraint'] = smalldata['constraints']
if self.subtype == 'split':
self.backend.set_fragments(smalldata['fragments'])
self.atom_id, dummy = self.backend.read_split(framedir, 'ID')
else:
self.atom_id = None
atoms = Atoms(**data)
natoms = smalldata['natoms']
for name in ('positions', 'numbers', 'tags', 'masses',
'momenta'):
if self.datatypes.get(name):
atoms.arrays[name] = self._read_data(framezero, framedir,
name, self.atom_id)
assert len(atoms.arrays[name]) == natoms
# Create the atoms object
if self.datatypes.get('energy'):
if self.datatypes.get('forces'):
forces = self.backend.read(framedir, 'forces')
else:
forces = None
if self.datatypes.get('magmoms'):
magmoms = self.backend.read(framedir, 'magmoms')
else:
magmoms = None
calc = SinglePointCalculator(atoms,
energy=smalldata.get('energy'),
forces=forces,
stress=smalldata.get('stress'),
magmoms=magmoms)
atoms.calc = calc
return atoms
def _read_data(self, f0, f, name, atom_id):
"Read single data item."
if self.subtype == 'normal':
if self.datatypes[name] == 'once':
d = self.backend.read(f0, name)
else:
d = self.backend.read(f, name)
elif self.subtype == 'split':
if self.datatypes[name] == 'once':
d, issplit = self.backend.read_split(f0, name)
atom_id, dummy = self.backend.read_split(f0, 'ID')
else:
d, issplit = self.backend.read_split(f, name)
if issplit:
assert atom_id is not None
assert len(d) == len(atom_id)
d[atom_id] = np.array(d)
return d
def __len__(self):
return self.nframes
def _open_log(self):
if not (self.master or self.slavelog):
return
if self.master:
lfn = os.path.join(self.filename, 'log.txt')
else:
lfn = os.path.join(self.filename, ('log-node%d.txt' %
(world.rank,)))
self.logfile = open(lfn, 'a', 1) # Append to log if it exists.
if hasattr(self, 'logdata'):
for text in self.logdata:
self.logfile.write(text + '\n')
self.logfile.flush()
del self.logdata
def _open_write(self, atoms, backup, backend):
"Open a bundle trajectory for writing."
self._set_backend(backend)
self.logfile = None # enable delayed logging
self.atoms = atoms
if os.path.exists(self.filename):
# The output directory already exists.
barrier() # all must have time to see it exists
if not self.is_bundle(self.filename, allowempty=True):
raise IOError(
'Filename "' + self.filename +
'" already exists, but is not a BundleTrajectory.' +
' Cowardly refusing to remove it.')
if self.is_empty_bundle(self.filename):
barrier()
self.log('Deleting old "%s" as it is empty' % (self.filename,))
self.delete_bundle(self.filename)
elif not backup:
barrier()
self.log('Deleting old "%s" as backup is turned off.' %
(self.filename,))
self.delete_bundle(self.filename)
else:
barrier()
# Make a backup file
bakname = self.filename + '.bak'
if os.path.exists(bakname):
barrier() # All must see it exists
self.log('Deleting old backup file "%s"' % (bakname,))
self.delete_bundle(bakname)
self.log('Renaming "%s" to "%s"' % (self.filename, bakname))
self._rename_bundle(self.filename, bakname)
# Ready to create a new bundle.
barrier()
self.log('Creating new "%s"' % (self.filename,))
self._make_bundledir(self.filename)
self.state = 'prewrite'
self._write_metadata({})
self._write_nframes(0) # Mark new bundle as empty
self._open_log()
self.nframes = 0
def _open_read(self):
"Open a bundle trajectory for reading."
if not os.path.exists(self.filename):
raise IOError('File not found: ' + self.filename)
if not self.is_bundle(self.filename):
raise IOError('Not a BundleTrajectory: ' + self.filename)
self.state = 'read'
# Read the metadata
metadata = self._read_metadata()
self.metadata = metadata
if metadata['version'] > self.version:
raise NotImplementedError(
'This version of ASE cannot read a BundleTrajectory version ' +
str(metadata['version']))
if metadata['subtype'] not in ('normal', 'split'):
raise NotImplementedError(
'This version of ASE cannot read BundleTrajectory subtype ' +
metadata['subtype'])
self.subtype = metadata['subtype']
if metadata['backend'] == 'ulm':
self.singleprecision = metadata['ulm.singleprecision']
self._set_backend(metadata['backend'])
self.nframes = self._read_nframes()
if self.nframes == 0:
raise IOError('Empty BundleTrajectory')
self.datatypes = metadata['datatypes']
try:
self.pythonmajor = metadata['python_ver'][0]
except KeyError:
self.pythonmajor = 2 # Assume written with Python 2.
# We need to know if we are running Python 3.X and try to read
# a bundle written with Python 2.X
self.backend.readpy2 = (self.pythonmajor == 2)
self.state = 'read'
def _open_append(self, atoms):
if not os.path.exists(self.filename):
# OK, no old bundle. Open as for write instead.
barrier()
self._open_write(atoms, False)
return
if not self.is_bundle(self.filename):
raise IOError('Not a BundleTrajectory: ' + self.filename)
self.state = 'read'
metadata = self._read_metadata()
self.metadata = metadata
if metadata['version'] != self.version:
raise NotImplementedError(
'Cannot append to a BundleTrajectory version '
'%s (supported version is %s)' % (str(metadata['version']),
str(self.version)))
if metadata['subtype'] not in ('normal', 'split'):
raise NotImplementedError(
'This version of ASE cannot append to BundleTrajectory '
'subtype ' + metadata['subtype'])
self.subtype = metadata['subtype']
if metadata['backend'] == 'ulm':
self.singleprecision = metadata['ulm.singleprecision']
self._set_backend(metadata['backend'])
self.nframes = self._read_nframes()
self._open_log()
self.log('Opening "%s" in append mode (nframes=%i)' % (self.filename,
self.nframes))
self.state = 'write'
self.atoms = atoms
@property
def path(self):
return Path(self.filename)
@property
def metadata_path(self):
return self.path / 'metadata.json'
def _write_nframes(self, n):
"Write the number of frames in the bundle."
assert self.state == 'write' or self.state == 'prewrite'
with paropen(self.path / 'frames', 'w') as fd:
fd.write(str(n) + '\n')
def _read_nframes(self):
"Read the number of frames."
return int((self.path / 'frames').read_text())
def _write_metadata(self, metadata):
"""Write the metadata file of the bundle.
Modifies the medadata dictionary!
"""
# Add standard fields that must always be present.
assert self.state == 'write' or self.state == 'prewrite'
metadata['format'] = 'BundleTrajectory'
metadata['version'] = self.version
metadata['subtype'] = self.subtype
metadata['backend'] = self.backend_name
if self.backend_name == 'ulm':
metadata['ulm.singleprecision'] = self.singleprecision
metadata['python_ver'] = tuple(sys.version_info)
encode = jsonio.MyEncoder(indent=4).encode
fido = encode(metadata)
with paropen(self.metadata_path, 'w') as fd:
fd.write(fido)
def _read_metadata(self):
"""Read the metadata."""
assert self.state == 'read'
return jsonio.decode(self.metadata_path.read_text())
[docs] @staticmethod
def is_bundle(filename, allowempty=False):
"""Check if a filename exists and is a BundleTrajectory.
If allowempty=True, an empty folder is regarded as an
empty BundleTrajectory."""
filename = Path(filename)
if not filename.is_dir():
return False
if allowempty and not os.listdir(filename):
return True # An empty BundleTrajectory
metaname = filename / 'metadata.json'
if metaname.is_file():
mdata = jsonio.decode(metaname.read_text())
else:
return False
try:
return mdata['format'] == 'BundleTrajectory'
except KeyError:
return False
[docs] @staticmethod
def is_empty_bundle(filename):
"""Check if a filename is an empty bundle.
Assumes that it is a bundle."""
if not os.listdir(filename):
return True # Empty folders are empty bundles.
with open(os.path.join(filename, 'frames'), 'rb') as fd:
nframes = int(fd.read())
# File may be removed by the master immediately after this.
barrier()
return nframes == 0
[docs] @classmethod
def delete_bundle(cls, filename):
"Deletes a bundle."
if world.rank == 0:
# Only the master deletes
if not cls.is_bundle(filename, allowempty=True):
raise IOError(
'Cannot remove "%s" as it is not a bundle trajectory.'
% (filename,))
if os.path.islink(filename):
# A symbolic link to a bundle. Only remove the link.
os.remove(filename)
else:
# A real bundle
shutil.rmtree(filename)
else:
# All other tasks wait for the directory to go away.
while os.path.exists(filename):
time.sleep(1)
# The master may not proceed before all tasks have seen the
# directory go away, as it might otherwise create a new bundle
# with the same name, fooling the wait loop in _make_bundledir.
barrier()
def _rename_bundle(self, oldname, newname):
"Rename a bundle. Used to create the .bak"
if self.master:
os.rename(oldname, newname)
else:
while os.path.exists(oldname):
time.sleep(1)
# The master may not proceed before all tasks have seen the
# directory go away.
barrier()
def _make_bundledir(self, filename):
"""Make the main bundle directory.
Since all MPI tasks might write to it, all tasks must wait for
the directory to appear.
"""
self.log('Making directory ' + filename)
assert not os.path.isdir(filename)
barrier()
if self.master:
os.mkdir(filename)
else:
i = 0
while not os.path.isdir(filename):
time.sleep(1)
i += 1
if i > 10:
self.log('Waiting %d seconds for %s to appear!'
% (i, filename))
def _make_framedir(self, frame):
"""Make subdirectory for the frame.
As only the master writes to it, no synchronization between
MPI tasks is necessary.
"""
framedir = os.path.join(self.filename, 'F' + str(frame))
if self.master:
self.log('Making directory ' + framedir)
os.mkdir(framedir)
return framedir
[docs] def pre_write_attach(self, function, interval=1, *args, **kwargs):
"""Attach a function to be called before writing begins.
function: The function or callable object to be called.
interval: How often the function is called. Default: every time (1).
All other arguments are stored, and passed to the function.
"""
if not callable(function):
raise ValueError('Callback object must be callable.')
self.pre_observers.append((function, interval, args, kwargs))
[docs] def post_write_attach(self, function, interval=1, *args, **kwargs):
"""Attach a function to be called after writing ends.
function: The function or callable object to be called.
interval: How often the function is called. Default: every time (1).
All other arguments are stored, and passed to the function.
"""
if not callable(function):
raise ValueError('Callback object must be callable.')
self.post_observers.append((function, interval, args, kwargs))
def _call_observers(self, obs):
"Call pre/post write observers."
for function, interval, args, kwargs in obs:
if (self.nframes + 1) % interval == 0:
function(*args, **kwargs)
class UlmBundleBackend:
"""Backend for BundleTrajectories stored as ASE Ulm files."""
def __init__(self, master, singleprecision):
# Store if this backend will actually write anything
self.writesmall = master
self.writelarge = master
self.singleprecision = singleprecision
# Integer data may be downconverted to the following types
self.integral_dtypes = ['uint8', 'int8', 'uint16', 'int16',
'uint32', 'int32', 'uint64', 'int64']
# Dict comprehensions not supported in Python 2.6 :-(
self.int_dtype = dict((k, getattr(np, k))
for k in self.integral_dtypes)
self.int_minval = dict((k, np.iinfo(self.int_dtype[k]).min)
for k in self.integral_dtypes)
self.int_maxval = dict((k, np.iinfo(self.int_dtype[k]).max)
for k in self.integral_dtypes)
self.int_itemsize = dict((k, np.dtype(self.int_dtype[k]).itemsize)
for k in self.integral_dtypes)
def write_small(self, framedir, smalldata):
"Write small data to be written jointly."
if self.writesmall:
with ulmopen(os.path.join(framedir, 'smalldata.ulm'), 'w') as fd:
fd.write(**smalldata)
def write(self, framedir, name, data):
"Write data to separate file."
if self.writelarge:
shape = data.shape
dtype = str(data.dtype)
stored_as = dtype
all_identical = False
# Check if it a type that can be stored with less space
if np.issubdtype(data.dtype, np.integer):
# An integer type, we may want to convert
minval = data.min()
maxval = data.max()
# ulm cannot write np.bool_:
all_identical = bool(minval == maxval)
if all_identical:
data = int(data.flat[0]) # Convert to standard integer
else:
for typ in self.integral_dtypes:
if (minval >= self.int_minval[typ] and
maxval <= self.int_maxval[typ] and
data.itemsize > self.int_itemsize[typ]):
# Convert to smaller type
stored_as = typ
data = data.astype(self.int_dtype[typ])
elif data.dtype == np.float32 or data.dtype == np.float64:
all_identical = bool(data.min() == data.max())
if all_identical:
data = float(data.flat[0]) # Convert to standard float
elif data.dtype == np.float64 and self.singleprecision:
# Downconvert double to single precision
stored_as = 'float32'
data = data.astype(np.float32)
fn = os.path.join(framedir, name + '.ulm')
with ulmopen(fn, 'w') as fd:
fd.write(shape=shape,
dtype=dtype,
stored_as=stored_as,
all_identical=all_identical,
data=data)
def read_small(self, framedir):
"Read small data."
with ulmopen(os.path.join(framedir, 'smalldata.ulm'), 'r') as fd:
return fd.asdict()
def read(self, framedir, name):
"Read data from separate file."
fn = os.path.join(framedir, name + '.ulm')
with ulmopen(fn, 'r') as fd:
if fd.all_identical:
# Only a single data value
data = np.zeros(fd.shape,
dtype=getattr(np, fd.dtype)) + fd.data
elif fd.dtype == fd.stored_as:
# Easy, the array can be returned as-is.
data = fd.data
else:
# Cast the data back
data = fd.data.astype(getattr(np, fd.dtype))
return data
def read_info(self, framedir, name, split=None):
"""Read information about file contents without reading the data.
Information is a dictionary containing as aminimum the shape and
type.
"""
fn = os.path.join(framedir, name + '.ulm')
if split is None or os.path.exists(fn):
with ulmopen(fn, 'r') as fd:
info = dict()
info['shape'] = fd.shape
info['type'] = fd.dtype
info['stored_as'] = fd.stored_as
info['identical'] = fd.all_identical
return info
else:
info = dict()
for i in range(split):
fn = os.path.join(framedir, name + '_' + str(i) + '.ulm')
with ulmopen(fn, 'r') as fd:
if i == 0:
info['shape'] = list(fd.shape)
info['type'] = fd.dtype
info['stored_as'] = fd.stored_as
info['identical'] = fd.all_identical
else:
info['shape'][0] += fd.shape[0]
assert info['type'] == fd.dtype
info['identical'] = info['identical'] and fd.all_identical
info['shape'] = tuple(info['shape'])
return info
def set_fragments(self, nfrag):
self.nfrag = nfrag
def read_split(self, framedir, name):
"""Read data from multiple files.
Falls back to reading from single file if that is how data is stored.
Returns the data and an object indicating if the data was really
read from split files. The latter object is False if not
read from split files, but is an array of the segment length if
split files were used.
"""
data = []
if os.path.exists(os.path.join(framedir, name + '.ulm')):
# Not stored in split form!
return (self.read(framedir, name), False)
for i in range(self.nfrag):
suf = '_%d' % (i,)
data.append(self.read(framedir, name + suf))
seglengths = [len(d) for d in data]
return (np.concatenate(data), seglengths)
def close(self, log=None):
"""Close anything that needs to be closed by the backend.
The default backend does nothing here.
"""
pass
[docs]def read_bundletrajectory(filename, index=-1):
"""Reads one or more atoms objects from a BundleTrajectory.
Arguments:
filename: str
The name of the bundle (really a directory!)
index: int
An integer specifying which frame to read, or an index object
for reading multiple frames. Default: -1 (reads the last
frame).
"""
traj = BundleTrajectory(filename, mode='r')
for i in range(*index.indices(len(traj))):
yield traj[i]
[docs]def write_bundletrajectory(filename, images, append=False):
"""Write image(s) to a BundleTrajectory.
Write also energy, forces, and stress if they are already
calculated.
"""
if append:
mode = 'a'
else:
mode = 'w'
traj = BundleTrajectory(filename, mode=mode)
if hasattr(images, 'get_positions'):
images = [images]
for atoms in images:
# Avoid potentially expensive calculations:
calc = atoms.calc
if hasattr(calc, 'calculation_required'):
for quantity in ('energy', 'forces', 'stress', 'magmoms'):
traj.select_data(quantity,
not calc.calculation_required(atoms,
[quantity]))
traj.write(atoms)
traj.close()
def print_bundletrajectory_info(filename):
"""Prints information about a BundleTrajectory.
Mainly intended to be called from a command line tool.
"""
if not BundleTrajectory.is_bundle(filename):
raise ValueError('Not a BundleTrajectory!')
if BundleTrajectory.is_empty_bundle(filename):
print(filename, 'is an empty BundleTrajectory.')
return
# Read the metadata
fn = os.path.join(filename, 'metadata.json')
with open(fn, 'r') as fd:
metadata = jsonio.decode(fd.read())
print('Metadata information of BundleTrajectory "%s":' % (filename,))
for k, v in metadata.items():
if k != 'datatypes':
print(" %s: %s" % (k, v))
with open(os.path.join(filename, 'frames'), 'rb') as fd:
nframes = int(fd.read())
print('Number of frames: %i' % (nframes,))
print('Data types:')
for k, v in metadata['datatypes'].items():
if v == 'once':
print(' %s: First frame only.' % (k,))
elif v:
print(' %s: All frames.' % (k,))
# Look at first frame
if metadata['backend'] == 'ulm':
backend = UlmBundleBackend(True, False)
else:
raise NotImplementedError('Backend %s not supported.'
% (metadata['backend'],))
frame = os.path.join(filename, 'F0')
small = backend.read_small(frame)
print('Contents of first frame:')
for k, v in small.items():
if k == 'constraints':
if v:
print(' {} constraints are present'.format(len(v)))
else:
print(' Constraints are absent.')
elif k == 'pbc':
print(' Periodic boundary conditions: %s' % (str(v),))
elif k == 'natoms':
print(' Number of atoms: %i' % (v,))
elif hasattr(v, 'shape'):
print(' %s: shape = %s, type = %s' %
(k, str(v.shape), str(v.dtype)))
if k == 'cell':
print(' [[%12.6f, %12.6f, %12.6f],' % tuple(v[0]))
print(' [%12.6f, %12.6f, %12.6f],' % tuple(v[1]))
print(' [%12.6f, %12.6f, %12.6f]]' % tuple(v[2]))
else:
print(' %s: %s' % (k, str(v)))
# Read info from separate files.
if metadata['subtype'] == 'split':
nsplit = small['fragments']
else:
nsplit = False
for k, v in metadata['datatypes'].items():
if v and k not in small:
info = backend.read_info(frame, k, nsplit)
infoline = ' %s: ' % (k,)
for k, v in info.items():
infoline += '%s = %s, ' % (k, str(v))
infoline = infoline[:-2] + '.' # Fix punctuation.
print(infoline)
class PickleBundleBackend:
# Leave placeholder class so importing asap3 won't crash.
pass
def main():
import optparse
parser = optparse.OptionParser(
usage='python -m ase.io.bundletrajectory '
'a.bundle [b.bundle ...]',
description='Print information about '
'the contents of one or more bundletrajectories.')
opts, args = parser.parse_args()
for name in args:
print_bundletrajectory_info(name)
if __name__ == '__main__':
main()