def test_register_event():
event = Event()
num_calls = {}
def callback():
num_calls['a'] = 'a'
event.register(callback)
event.notify()
assert event.notify_count == 1
assert num_calls['a'] == 'a'
class CTF(HasAcceleratorMixin):
def __init__(self,
semiangle_cutoff: float = np.inf,
rolloff: float = 0.,
focal_spread: float = 0.,
angular_spread: float = 0.,
gaussian_spread: float = 0.,
energy: float = None,
parameters: Mapping[str, float] = None,
**kwargs):
for key in kwargs.keys():
if ((key not in polar_symbols)
and (key not in polar_aliases.keys())):
raise ValueError('{} not a recognized parameter'.format(key))
self.changed = Event()
self._accelerator = Accelerator(energy=energy)
self._semiangle_cutoff = semiangle_cutoff
self._rolloff = rolloff
self._focal_spread = focal_spread
self._angular_spread = angular_spread
self._gaussian_spread = gaussian_spread
self._parameters = dict(zip(polar_symbols, [0.] * len(polar_symbols)))
if parameters is None:
parameters = {}
parameters.update(kwargs)
self.set_parameters(parameters)
def parametrization_property(key):
def getter(self):
return self._parameters[key]
def setter(self, value):
old = getattr(self, key)
self._parameters[key] = value
self.changed.notify(**{
'notifier': self,
'property_name': key,
'change': old != value
})
return property(getter, setter)
for symbol in polar_symbols:
setattr(self.__class__, symbol, parametrization_property(symbol))
for key, value in polar_aliases.items():
if key != 'defocus':
setattr(self.__class__, key, parametrization_property(value))
@property
def parameters(self):
return self._parameters
@property
def defocus(self) -> float:
return -self._parameters['C10']
@defocus.setter
def defocus(self, value: float):
self.C10 = -value
@property
def semiangle_cutoff(self) -> float:
return self._semiangle_cutoff
@semiangle_cutoff.setter
@watched_property('changed')
def semiangle_cutoff(self, value: float):
self._semiangle_cutoff = value
@property
def rolloff(self) -> float:
return self._rolloff
@rolloff.setter
@watched_property('changed')
def rolloff(self, value: float):
self._rolloff = value
@property
def focal_spread(self) -> float:
return self._focal_spread
@focal_spread.setter
@watched_property('changed')
def focal_spread(self, value: float):
self._focal_spread = value
@property
def angular_spread(self) -> float:
return self._angular_spread
@angular_spread.setter
@watched_property('changed')
def angular_spread(self, value: float):
self._angular_spread = value
@property
def gaussian_spread(self) -> float:
return self._gaussian_spread
@gaussian_spread.setter
@watched_property('changed')
def gaussian_spread(self, value: float):
self._gaussian_spread = value
@watched_method('changed')
def set_parameters(self, parameters):
for symbol, value in parameters.items():
if symbol in self._parameters.keys():
self._parameters[symbol] = value
elif symbol == 'defocus':
self._parameters[polar_aliases[symbol]] = -value
elif symbol in polar_aliases.keys():
self._parameters[polar_aliases[symbol]] = value
else:
raise ValueError(
'{} not a recognized parameter'.format(symbol))
return parameters
def evaluate_aperture(self, alpha) -> np.ndarray:
xp = get_array_module(alpha)
semiangle_cutoff = self.semiangle_cutoff / 1000.
if self.rolloff > 0.:
rolloff = self.rolloff * semiangle_cutoff
array = .5 * (
1 + xp.cos(np.pi *
(alpha - semiangle_cutoff + rolloff) / rolloff))
array[alpha > semiangle_cutoff] = 0.
array = xp.where(alpha > semiangle_cutoff - rolloff, array,
xp.ones_like(alpha, dtype=xp.float32))
else:
array = xp.array(alpha < semiangle_cutoff).astype(xp.float32)
return array
def evaluate_temporal_envelope(self, alpha: np.ndarray) -> np.ndarray:
xp = get_array_module(alpha)
return xp.exp(-(.5 * xp.pi / self.wavelength * self.focal_spread *
alpha**2)**2).astype(xp.float32)
def evaluate_gaussian_envelope(self, alpha: np.ndarray) -> np.ndarray:
xp = get_array_module(alpha)
return xp.exp(-.5 * self.gaussian_spread**2 * alpha**2 /
self.wavelength**2)
def evaluate_spatial_envelope(self, alpha, phi):
xp = get_array_module(alpha)
p = self.parameters
dchi_dk = 2 * xp.pi / self.wavelength * (
(p['C12'] * xp.cos(2. * (phi - p['phi12'])) + p['C10']) * alpha +
(p['C23'] * xp.cos(3. * (phi - p['phi23'])) +
p['C21'] * xp.cos(1. * (phi - p['phi21']))) * alpha**2 +
(p['C34'] * xp.cos(4. * (phi - p['phi34'])) +
p['C32'] * xp.cos(2. *
(phi - p['phi32'])) + p['C30']) * alpha**3 +
(p['C45'] * xp.cos(5. * (phi - p['phi45'])) +
p['C43'] * xp.cos(3. * (phi - p['phi43'])) +
p['C41'] * xp.cos(1. * (phi - p['phi41']))) * alpha**4 +
(p['C56'] * xp.cos(6. * (phi - p['phi56'])) +
p['C54'] * xp.cos(4. * (phi - p['phi54'])) +
p['C52'] * xp.cos(2. * (phi - p['phi52'])) + p['C50']) * alpha**5)
dchi_dphi = -2 * xp.pi / self.wavelength * (
1 / 2. *
(2. * p['C12'] * xp.sin(2. *
(phi - p['phi12']))) * alpha + 1 / 3. *
(3. * p['C23'] * xp.sin(3. * (phi - p['phi23'])) +
1. * p['C21'] * xp.sin(1. *
(phi - p['phi21']))) * alpha**2 + 1 / 4. *
(4. * p['C34'] * xp.sin(4. * (phi - p['phi34'])) +
2. * p['C32'] * xp.sin(2. *
(phi - p['phi32']))) * alpha**3 + 1 / 5. *
(5. * p['C45'] * xp.sin(5. * (phi - p['phi45'])) +
3. * p['C43'] * xp.sin(3. * (phi - p['phi43'])) +
1. * p['C41'] * xp.sin(1. *
(phi - p['phi41']))) * alpha**4 + 1 / 6. *
(6. * p['C56'] * xp.sin(6. * (phi - p['phi56'])) +
4. * p['C54'] * xp.sin(4. * (phi - p['phi54'])) +
2. * p['C52'] * xp.sin(2. * (phi - p['phi52']))) * alpha**5)
return xp.exp(-xp.sign(self.angular_spread) *
(self.angular_spread / 1000. / 2)**2 *
(dchi_dk**2 + dchi_dphi**2))
def evaluate_chi(self, alpha, phi) -> np.ndarray:
"""
Calculates the polar expansion of the phase error up to 5th order.
See Eq. 2.22 in ref [1].
Parameters
----------
alpha : numpy.ndarray
Angle between the scattered electrons and the optical axis [mrad].
phi : numpy.ndarray
Angle around the optical axis of the scattered electrons [mrad].
wavelength : float
Relativistic wavelength of wavefunction [Å].
parameters : Mapping[str, float]
Mapping from Cnn, phinn coefficients to their corresponding values. See parameter `parameters` in class CTFBase.
Returns
-------
References
----------
.. [1] Kirkland, E. J. (2010). Advanced Computing in Electron Microscopy (2nd ed.). Springer.
"""
xp = get_array_module(alpha)
p = self.parameters
alpha2 = alpha**2
array = xp.zeros(alpha.shape, dtype=np.float32)
if any([p[symbol] != 0. for symbol in ('C10', 'C12', 'phi12')]):
array += (1 / 2 * alpha2 *
(p['C10'] + p['C12'] * xp.cos(2 * (phi - p['phi12']))))
if any(
[p[symbol] != 0. for symbol in ('C21', 'phi21', 'C23', 'phi23')]):
array += (1 / 3 * alpha2 * alpha *
(p['C21'] * xp.cos(phi - p['phi21']) +
p['C23'] * xp.cos(3 * (phi - p['phi23']))))
if any([
p[symbol] != 0.
for symbol in ('C30', 'C32', 'phi32', 'C34', 'phi34')
]):
array += (1 / 4 * alpha2**2 *
(p['C30'] + p['C32'] * xp.cos(2 * (phi - p['phi32'])) +
p['C34'] * xp.cos(4 * (phi - p['phi34']))))
if any([
p[symbol] != 0.
for symbol in ('C41', 'phi41', 'C43', 'phi43', 'C45', 'phi41')
]):
array += (1 / 5 * alpha2**2 * alpha *
(p['C41'] * xp.cos((phi - p['phi41'])) +
p['C43'] * xp.cos(3 * (phi - p['phi43'])) +
p['C45'] * xp.cos(5 * (phi - p['phi45']))))
if any([
p[symbol] != 0. for symbol in ('C50', 'C52', 'phi52', 'C54',
'phi54', 'C56', 'phi56')
]):
array += (1 / 6 * alpha2**3 *
(p['C50'] + p['C52'] * xp.cos(2 * (phi - p['phi52'])) +
p['C54'] * xp.cos(4 * (phi - p['phi54'])) +
p['C56'] * xp.cos(6 * (phi - p['phi56']))))
array = 2 * xp.pi / self.wavelength * array
return array
def evaluate_aberrations(self, alpha, phi) -> np.ndarray:
xp = get_array_module(alpha)
complex_exponential = get_device_function(xp, 'complex_exponential')
return complex_exponential(-self.evaluate_chi(alpha, phi))
def evaluate(self, alpha, phi):
alpha = np.array(alpha)
phi = np.array(phi)
array = self.evaluate_aberrations(alpha, phi)
if self.semiangle_cutoff < np.inf:
array *= self.evaluate_aperture(alpha)
if self.focal_spread > 0.:
array *= self.evaluate_temporal_envelope(alpha)
if self.angular_spread > 0.:
array *= self.evaluate_spatial_envelope(alpha, phi)
if self.gaussian_spread > 0.:
array *= self.evaluate_gaussian_envelope(alpha)
return array
def show(self,
semiangle_cutoff: float,
ax=None,
phi=0,
n=1000,
title=None,
**kwargs):
import matplotlib.pyplot as plt
alpha = np.linspace(0, semiangle_cutoff, n)
aberrations = self.evaluate_aberrations(alpha, phi)
aperture = self.evaluate_aperture(alpha)
temporal_envelope = self.evaluate_temporal_envelope(alpha)
spatial_envelope = self.evaluate_spatial_envelope(alpha, phi)
gaussian_envelope = self.evaluate_gaussian_envelope(alpha)
envelope = aperture * temporal_envelope * spatial_envelope * gaussian_envelope
if ax is None:
ax = plt.subplot()
ax.plot(alpha * 1000,
aberrations.imag * envelope,
label='CTF',
**kwargs)
if self.semiangle_cutoff < np.inf:
ax.plot(alpha * 1000, aperture, label='Aperture', **kwargs)
if self.focal_spread > 0.:
ax.plot(alpha * 1000,
temporal_envelope,
label='Temporal envelope',
**kwargs)
if self.angular_spread > 0.:
ax.plot(alpha * 1000,
spatial_envelope,
label='Spatial envelope',
**kwargs)
if self.gaussian_spread > 0.:
ax.plot(alpha * 1000,
gaussian_envelope,
label='Gaussian envelope',
**kwargs)
if not np.allclose(envelope, 1.):
ax.plot(alpha * 1000, envelope, label='Product envelope', **kwargs)
ax.set_xlabel('alpha [mrad.]')
if title is not None:
ax.set_title(title)
ax.legend()
def copy(self):
parameters = self.parameters.copy()
return self.__class__(semiangle_cutoff=self.semiangle_cutoff,
rolloff=self.rolloff,
focal_spread=self.focal_spread,
angular_spread=self.angular_spread,
gaussian_spread=self.gaussian_spread,
energy=self.energy,
parameters=parameters)