def read_observable_pressure(self, data_set_name="_pressure"):
"""
Reads back the output of the "pressure" observable. As the pressure can be computed from the number of particles
and the virial, this actually reads back the n_particles and virial observables. The data_set_name serves as a
postfix, where the default value corresponds to the data sets as they are created when using the default
settings of the observable.
:param data_set_name: the data set name postfix, default="_pressure",
yielding "n_particles_pressure" and "virial_pressure", respectively
:return: a tuple which contains an array corresponding to the time as first entry and an array containing the
corresponding pressure per time step
"""
time_n_particles, n_particles = self.read_observable_number_of_particles(
"n_particles{}".format(data_set_name))
time_virial, virial = self.read_observable_virial(
"virial{}".format(data_set_name))
if not _np.array_equal(time_n_particles, time_virial):
raise RuntimeError(
"For Pressure it is required to know the number of particles and the virial. "
"However, these two observables were recorded with different strides."
)
pressure = _np.array([
_calculate_pressure(self.box_volume, self.kbt, n_particles[i],
virial[i])
for i in range(len(time_n_particles))
])
return time_virial, pressure
def _eval_user_callback(self):
if self._n is not None and self._v is not None:
self._user_callback(
_calculate_pressure(box_volume=self._volume,
kbt=self._kbt,
n_particles=self._n,
virial=self._v))
self._n = None
self._v = None
def read_observable_pressure(self, data_set_name="_pressure"):
"""
Reads back the output of the "pressure" observable. As the pressure can be computed from the number of particles
and the virial, this actually reads back the n_particles and virial observables. The data_set_name serves as a
postfix, where the default value corresponds to the data sets as they are created when using the default
settings of the observable.
:param data_set_name: the data set name postfix, default="_pressure",
yielding "n_particles_pressure" and "virial_pressure", respectively
:return: a tuple which contains an array corresponding to the time as first entry and an array containing the
corresponding pressure per time step
"""
time_n_particles, n_particles = self.read_observable_number_of_particles("n_particles{}".format(data_set_name))
time_virial, virial = self.read_observable_virial("virial{}".format(data_set_name))
if not _np.array_equal(time_n_particles, time_virial):
raise RuntimeError("For Pressure it is required to know the number of particles and the virial. "
"However, these two observables were recorded with different strides.")
pressure = _np.array([_calculate_pressure(self.box_volume, self.kbt, n_particles[i], virial[i])
for i in range(len(time_n_particles))])
return time_virial, pressure
def _eval_user_callback(self):
if self._n is not None and self._v is not None:
self._user_callback(_calculate_pressure(box_volume=self._volume, kbt=self._kbt,
n_particles=self._n, virial=self._v))
self._n = None
self._v = None