"""Lattice object
The methods implemented in this module are internal to the 'lattice' package.
This is necessary to ensure that the 'lattice' package is independent of other
AT packages.
Other Lattice methods are implemented in other AT packages and are available
as soon as the package is imported. The 'tracking' and 'physics' packages are
automatically imported.
As an example, see the at.physics.orbit module
"""
from __future__ import annotations
__all__ = ['Lattice', 'Filter', 'type_filter', 'params_filter', 'lattice_filter',
'elem_generator', 'no_filter']
import sys
import copy
import math
from typing import Optional, Union
if sys.version_info.minor < 9:
from typing import Callable, Iterable, Generator
SupportsIndex = int
else:
from typing import SupportsIndex
from collections.abc import Callable, Iterable, Generator
from warnings import warn
import numpy
from . import elements as elt
from .elements import Element
from .particle_object import Particle
from .utils import AtError, AtWarning, Refpts
from .utils import get_s_pos, get_elements, get_value_refpts, set_value_refpts
# noinspection PyProtectedMember
from .utils import get_uint32_index, get_bool_index, _refcount, Uint32Refpts
from .utils import refpts_iterator, checktype, set_shift, set_tilt, get_geometry
from ..constants import clight, e_mass
_TWO_PI_ERROR = 1.E-4
Filter = Callable[..., Iterable[Element]]
_DEFAULT_PASS = {
False: (
('cavity_pass', elt.RFCavity, 'auto'),
('dipole_pass', elt.Dipole, 'auto'),
('quadrupole_pass', elt.Quadrupole, 'auto'),
('wiggler_pass', elt.Wiggler, 'auto'),
('sextupole_pass', elt.Sextupole, 'auto'),
('octupole_pass', elt.Octupole, 'auto'),
('multipole_pass', elt.Multipole, 'auto'),
('collective_pass', elt.Collective, 'auto'),
('diffusion_pass', elt.QuantumDiffusion, 'auto'),
('energyloss_pass', elt.EnergyLoss, 'auto'),
('simplequantdiff_pass', elt.SimpleQuantDiff, 'auto'),
('simpleradiation_pass', elt.SimpleRadiation, 'auto')
),
True: (
('cavity_pass', elt.RFCavity, 'auto'),
('dipole_pass', elt.Dipole, 'auto'),
('quadrupole_pass', elt.Quadrupole, 'auto'),
('wiggler_pass', elt.Wiggler, 'auto'),
('sextupole_pass', elt.Sextupole, None),
('octupole_pass', elt.Octupole, None),
('multipole_pass', elt.Multipole, None),
('collective_pass', elt.Collective, 'auto'),
('diffusion_pass', elt.QuantumDiffusion, 'auto'),
('energyloss_pass', elt.EnergyLoss, 'auto'),
('simplequantdiff_pass', elt.SimpleQuantDiff, 'auto'),
('simpleradiation_pass', elt.SimpleRadiation, 'auto')
)
}
# Don't warn on floating-point errors
numpy.seterr(divide='ignore', invalid='ignore')
# noinspection PyAttributeOutsideInit
[docs]
class Lattice(list):
"""Lattice object.
An AT lattice is a sequence of AT elements. In addition to :py:class:`list`
methods, :py:class:`Lattice` supports
`extended indexing <https://numpy.org/doc/stable/user/basics.indexing.html
#advanced-indexing>`_ as a numpy :py:obj:`~numpy.ndarray`.
"""
# Attributes displayed:
_disp_attributes = ('name', 'energy', 'particle', 'periodicity',
'harmonic_number', 'beam_current', 'nbunch')
# excluded attributes
_excluded_attributes = ('nbunch', )
# Attributes propagated in copies:
_std_attributes = ('name', '_energy', '_particle', 'periodicity',
'_cell_harmnumber', '_radiation', '_beam_current',
'_fillpattern')
# noinspection PyUnusedLocal
def __init__(self, *args, iterator: Filter = None, scan: bool = False, **kwargs):
"""
Lattice(elements, **params)
Lattice(filter, [filter, ...,] iterator=iter,**params)
Parameters:
elements: iterable of Element objects
iter: function called as :pycode:`iter(params, *args)`. It must
return an iterable of :py:class:`.Element` objects for building
the lattice. It must also fill the *params* dictionary providing
the Lattice attributes.
params: dictionary of lattice parameters. A custom iterator may
add, remove or modify parameters. Finally, the remaining
parameters will be set as Lattice attributes.
Keyword Arguments:
name='': Name of the lattice
energy: Energy of the lattice
periodicity=1: Number of periods
particle='relativistic': circulating particle. May be
'relativistic', 'electron', 'positron', 'proton'
or a Particle object
iterator=None: custom iterator (see below)
*: all other keywords will be set as attributes of
the Lattice object
beam_current: Total current in the beam, used for collective
effects
An iterator ``it`` is called as ``it(params, *args)`` where ``args``
and ``params`` are the arguments of the ``Lattice`` constructor. It
must yield the AT ``Elements`` for building the lattice. It must
also fill its ``params`` dictionary argument, which will be used to
set the ``Lattice`` attributes.
An iterator can be:
- a "generator" which yields elements from scratch.
Examples: a list, or a file iterator,
- a "filter" which runs through an input iterator, processes each
element, possibly adds parameters to the params dictionary
and yields the processed elements.
.. Note::
To reduce the inter-package dependencies, some methods of the
lattice object are defined in other AT packages, in the module where
the underlying function is implemented.
.. Note::
It is possible to define a filling pattern for the beam using the
function ``ring.set_fillingpattern()``. The default configuration
(no arguments) is for single bunch and is the one loaded at lattice
initialization. See function help for details.
Changing ``Lattice.harmonic_number`` will reset the filling pattern
to its default configuration.
The beam current can be changed with
``Lattice.beam_current=current``
The filling pattern and beam current are used by collective effects
passmethods.
Examples:
Chaining iterators (taken from ``load_mat``):
.. code-block:: python
Lattice(ringparam_filter, matfile_generator, filename
iterator=params_filter, **params)
``matfile_generator(params, filename)``
opens filename and generates AT elements for each cell of the
Matlab cell array representing the lattice,
``ringparam_filter(params, matfile_generator, *args)``
runs through ``matfile_generator(params, *args)``, looks for
RingParam elements, fills params with their information and
discards them,
``params_filter(params, ringparam_filter, *args)``
runs through ``ringparam_filter(params, *args)``, looks for
energy and periodicity if not yet defined.
"""
if iterator is None:
(arg1,) = args or [[]] # accept 0 or 1 argument
if isinstance(arg1, Lattice):
elems = lattice_filter(kwargs, arg1)
else:
elems = params_filter(kwargs, type_filter, arg1)
else:
elems = iterator(kwargs, *args)
super(Lattice, self).__init__(elems)
# removing excluded attributes
for attr in self._excluded_attributes:
kwargs.pop(attr, None)
# set default values
kwargs.setdefault("name", "")
periodicity = kwargs.setdefault("periodicity", 1)
kwargs.setdefault("particle", kwargs.pop("_particle", Particle()))
kwargs.setdefault("beam_current", kwargs.pop("_beam_current", 0.0))
# dummy initialization in case the harmonic number is not there
kwargs.setdefault("_fillpattern", numpy.ones(1))
# Remove temporary keywords
frequency: Optional[float] = kwargs.pop("_frequency", None)
cell_length: Optional[float] = kwargs.pop("_length", None)
cell_h = kwargs.pop("cell_harmnumber", kwargs.pop("_cell_harmnumber", math.nan))
ring_h = kwargs.pop("harmonic_number", cell_h * periodicity)
energy = kwargs.setdefault("energy", kwargs.pop("_energy", None))
if energy is None:
raise AtError("Lattice energy is not defined")
# set attributes
self.update(kwargs)
# Setting the harmonic number is delayed to have self.beta available
if not (frequency is None or frequency == 0.0):
rev = self.beta * clight / cell_length
self._cell_harmnumber = int(round(frequency / rev))
try:
fp = kwargs.pop("_fillpattern", numpy.ones(1))
self.set_fillpattern(bunches=fp)
except AssertionError:
self.set_fillpattern()
elif not ((ring_h is None) or math.isnan(ring_h)):
self._cell_harmnumber = ring_h / periodicity
def __getitem__(self, key):
try: # Integer
return super(Lattice, self).__getitem__(key.__index__())
except (AttributeError, TypeError):
if isinstance(key, slice): # Slice
rg = range(*key.indices(len(self)))
else: # Array of integers or boolean
rg = get_uint32_index(self, key, endpoint=False)
return Lattice(elem_generator,
(super(Lattice, self).__getitem__(i) for i in rg),
iterator=self.attrs_filter)
def __setitem__(self, key, values):
try: # Integer or slice
super(Lattice, self).__setitem__(key, values)
except TypeError: # Array of integers or boolean
rg = get_uint32_index(self, key, endpoint=False)
for i, v in zip(*numpy.broadcast_arrays(rg, values)):
super(Lattice, self).__setitem__(i, v)
def __delitem__(self, key):
try: # Integer or slice
super(Lattice, self).__delitem__(key)
except TypeError: # Array of integers or boolean
rg = get_uint32_index(self, key, endpoint=False)
for i in reversed(rg):
super(Lattice, self).__delitem__(i)
def __repr__(self):
ks = ', '.join('{0}={1!r}'.format(k, v) for k, v in self.attrs.items())
return 'Lattice({0}, {1})'.format(super(Lattice, self).__repr__(), ks)
def __str__(self):
ks = ', '.join('{0}={1!r}'.format(k, v) for k, v in self.attrs.items())
return 'Lattice(<{0} elements>, {1})'.format(len(self), ks)
def __add__(self, elems):
"""Add elems, an iterable of AT elements, to the lattice"""
return self.concatenate(elems, copy=True)
def __iadd__(self, elems):
self.concatenate(elems, copy=False)
return self
def __mul__(self, n):
return self.repeat(n)
def _addition_filter(self, elems: Iterable[Element], copy_elements=False):
cavities = []
length = 0.0
params = {}
for elem in type_filter(params, elems):
if isinstance(elem, elt.RFCavity):
cavities.append(elem)
elem.Energy = self._energy
elif elem.PassMethod.endswith('RadPass'):
elem.Energy = self._energy
elif hasattr(elem, 'Energy'):
del elem.Energy
elif hasattr(elem, '_turnhistory'):
elem.clear_history(self)
length += getattr(elem, 'Length', 0.0)
if copy_elements:
yield elem.deepcopy()
else:
yield elem
if cavities and not hasattr(self, '_cell_harmnumber'):
cavities.sort(key=lambda el: el.Frequency)
try:
self._cell_harmnumber = cavities[0].HarmNumber
except AttributeError:
length += self.get_s_pos(len(self))[0]
rev = self.beta * clight / length
frequency = cavities[0].Frequency
self._cell_harmnumber = int(round(frequency / rev))
self._radiation |= params.pop('_radiation')
[docs]
def insert(self, idx: SupportsIndex, elem: Element, copy_elements=False):
r"""This method allow to insert an AT element in the lattice.
Parameters:
idx (SupportsIndex): index at which the lement is inserted
elem (Element): AT element to be inserted in the lattice
copy_elements(bool): Default :py:obj:`True`.
If :py:obj:`True` a deep copy of elem
is used.
"""
# scan the new element to update it
elist = list(self._addition_filter([elem], # noqa: F841
copy_elements=copy_elements))
super().insert(idx, elem)
[docs]
def extend(self, elems: Iterable[Element], copy_elements=False):
# noinspection PyUnresolvedReferences
r"""This method adds all the elements of `elems` to the end of the
lattice. The behavior is the same as for a :py:obj:`list`
Equivalent syntaxes:
>>> ring.extend(elems)
>>> ring += elems
Parameters:
elems (Iterable[Element]): Sequence of AT elements to be
appended to the lattice
copy_elements(bool): Default :py:obj:`True`.
If :py:obj:`True` deep copies of each
element of elems are used
"""
if hasattr(self, '_energy'):
# When unpickling a Lattice, extend is called before the lattice
# is initialized. So skip this.
elems = self._addition_filter(elems, copy_elements=copy_elements)
super().extend(elems)
[docs]
def append(self, elem: Element, copy_elements=False):
# noinspection PyUnresolvedReferences
r"""This method overwrites the inherited method :py:meth:`list.append()`,
its behavior is changed, it accepts only AT lattice elements
:py:obj:`Element` as input argument.
Equivalent syntaxes:
>>> ring.append(elem)
>>> ring += [elem]
Parameters:
elem (Element): AT element to be appended to the lattice
copy_elements(bool): Default :py:obj:`True`.
If :py:obj:`True` a deep copy of elem
is used
"""
self.extend([elem], copy_elements=copy_elements)
[docs]
def repeat(self, n: int, copy_elements: bool = True):
# noinspection SpellCheckingInspection,PyUnresolvedReferences,PyRedeclaration
r"""This method allows to repeat the lattice `n` times.
If `n` does not divide `ring.periodicity`, the new ring
periodicity is set to 1, otherwise it is set to
`ring.periodicity /= n`.
Equivalent syntaxes:
>>> newring = ring.repeat(n)
>>> newring = ring * n
Parameters:
n : number of repetitions
copy_elements: If :py:obj:`True`, deep copies of the lattice are used for
the repetition. Otherwise, the original elements are repeated in the
developed lattice.
Returns:
newring (Lattice): the new repeated lattice
"""
def copy_fun(elem, copy):
if copy:
return elem.deepcopy()
else:
return elem
periodicity = self.periodicity
if n != 0 and periodicity > 1:
nbp = periodicity / n
periodicity = int(round(nbp))
if abs(periodicity - nbp) > _TWO_PI_ERROR:
warn(AtWarning('Non-integer number of cells: {}/{}. Periodi'
'city set to 1'.format(self.periodicity, n)))
periodicity = 1
hdict = dict(periodicity=periodicity)
try:
hdict.update(harmonic_number=self.cell_harmnumber*n*periodicity)
except AttributeError:
pass
elems = (copy_fun(el, copy_elements) for _ in range(n) for el in self)
return Lattice(elem_generator, elems, iterator=self.attrs_filter,
**hdict)
[docs]
def concatenate(self, *lattices: Iterable[Element],
copy_elements=False, copy=False):
# noinspection PyUnresolvedReferences,SpellCheckingInspection,PyRedeclaration
"""Concatenate several `Iterable[Element]` with the lattice
Equivalent syntaxes:
>>> newring = ring.concatenate(r1, r2, r3, copy=True)
>>> newring = ring + r1 + r2 + r3
>>> ring.concatenate(r1, copy=False)
>>> ring += r1
Parameters:
lattices: :py:obj:`Iterables[Element]` to be concatenanted
to the Lattice, several lattices are allowed
(see example)
copy_elements(bool): Default :py:obj:`False`. If :py:obj:`True`
deepcopies of the elements of lattices are used
copy(bool): Default :py:obj:`False`. If :py:obj:`True`
the lattice is modified in place.
Oterwise a new Lattice object is returned
Returns:
lattice(Lattice): concatenated Lattice, if `copy==True` the
new lattice object is returned
otherwise None
"""
if copy:
lattice = Lattice(self)
else:
lattice = self
for lat in lattices:
lattice.extend(lat, copy_elements=copy_elements)
return lattice if copy else None
[docs]
def reverse(self, copy=False):
# noinspection PyUnresolvedReferences
r"""Reverse the order of the lattice and swapt the faces
of elements. Alignment errors are not swapped
Parameters:
copy(bool): Default :py:obj:`False`. If :py:obj:`True`
the lattice is modified in place.
Oterwise a new Lattice object is returned
Returns:
lattice(Lattice): reversed Lattice, if `copy==True` the
new lattice object is returned
otherwise None
Example:
>>> newring = ring.reverse(copy=True)
"""
elems = (el.swap_faces(copy=True) for el in reversed(self))
if copy:
return Lattice(elem_generator, elems, iterator=self.attrs_filter)
else:
reversed_list = list(elems)
self[:] = reversed_list
[docs]
def develop(self, copy_elements: bool = True) -> Lattice:
"""Develop a periodical lattice by repeating its elements
*self.periodicity* times
Parameters:
copy_elements: If :py:obj:`True`, deep copies of the elements are used for
the repetition. Otherwise, the original elements are repeated in the
developed lattice.
Returns:
newlattice: The developed lattice
"""
return self.repeat(self.periodicity, copy_elements=copy_elements)
@property
def attrs(self) -> dict:
"""Dictionary of lattice attributes"""
def extattr(d):
for k in self._disp_attributes:
d.pop(k, None)
yield k, getattr(self, k, None)
vrs = vars(self).copy()
# Standard attributes
res = {k: v for k, v in extattr(vrs) if v is not None}
# Custom attributes
res.update((k, v) for k, v in vrs.items() if not k.startswith('_'))
return res
[docs]
def rotate(self, n: int) -> Lattice:
"""Return a new lattice rotated left by n elements"""
if len(self) == 0:
return self.copy()
n = n % len(self) # works for n<0
return self[n:] + self[:n]
[docs]
def update(self, *args, **kwargs) -> None:
"""
update(**kwargs)
update(mapping, **kwargs)
update(iterable, **kwargs)
Update the lattice attributes with the given values
"""
attrs = dict(*args, **kwargs)
for (key, value) in attrs.items():
setattr(self, key, value)
[docs]
def copy(self) -> Lattice:
"""Returns a shallow copy of the lattice"""
return copy.copy(self)
[docs]
def deepcopy(self) -> Lattice:
"""Returns a deep copy of the lattice"""
return copy.deepcopy(self)
[docs]
def slice_elements(self, refpts: Refpts, slices: int = 1) -> Lattice:
"""Create a new lattice by slicing the elements at refpts
Parameters:
refpts: Element selector
slices: Number of slices in the specified range. Ignored if
size is specified. Default: no slicing
Returns:
newring: New Lattice object
"""
def slice_generator(_):
check = get_bool_index(self, refpts)
for el, ok in zip(self, check):
if ok and (slices > 1):
frac = numpy.ones(slices) / slices
for elem in el.divide(frac):
yield elem
else:
yield el
return Lattice(slice_generator, iterator=self.attrs_filter)
[docs]
def slice(self, size: Optional[float] = None, slices: Optional[int] = 1) \
-> Lattice:
"""Create a new lattice by slicing the range of interest into small
elements
Keyword arguments:
size=None: Length of a slice. Default: computed from the
range and number of points: ``size = (s_max-s_min)/slices``.
slices=1: Number of slices in the specified range. Ignored if
size is specified. Default: no slicing
Returns:
newring: New Lattice object
"""
def slice_generator(_, ibeg, iend):
yield from self[:ibeg]
for elem in self[ibeg:iend]:
nslices = int(math.ceil(elem.Length / size))
if nslices > 1:
frac = numpy.ones(nslices) / nslices
for el in elem.divide(frac):
yield el
else:
yield elem
yield from self[iend:]
s_range = self.s_range
if size is None:
smin, smax = s_range
size = (smax - smin) / slices
i_range = self.i_range
return Lattice(slice_generator, i_range[0], i_range[-1],
iterator=self.attrs_filter, s_range=s_range)
[docs]
def attrs_filter(self, params: dict, elem_filter: Filter, *args) \
-> Iterable[Element]:
"""Filter function which duplicates the lattice attributes
Parameters:
params: Dictionary of Lattice attributes
elem_filter: Element filter
*args: Arguments provided to *elem_filter*
"""
for key in self._std_attributes:
try:
params.setdefault(key, getattr(self, key))
except AttributeError:
pass
return elem_filter(params, *args)
@property
def s_range(self) -> Union[None, tuple[float, float]]:
"""Range of interest: (s_min, s_max). :py:obj:`None` means
the full cell."""
try:
return self._s_range
except AttributeError:
self.s_range = None
return self._s_range
# noinspection PyAttributeOutsideInit
@s_range.setter
def s_range(self, value: Optional[tuple[float, float]]):
spos = self.get_s_pos(range(len(self) + 1))
if value is None:
value = (0.0, spos[-1])
ok = numpy.flatnonzero(
numpy.logical_and(spos > value[0], spos < value[1]))
if len(ok) > 0:
i1 = max(ok[0] - 1, 0)
i2 = min(ok[-1] + 1, len(self))
self._i_range = range(i1, i2 + 1)
else:
self._i_range = range(0, 0)
self._s_range = value
@property
def i_range(self) -> Uint32Refpts:
"""Range of elements inside the range of interest"""
try:
i_range = self._i_range
except AttributeError:
self.s_range = None
i_range = self._i_range
return get_uint32_index(self, i_range)
@property
def energy(self) -> float:
"""Lattice energy"""
return self._energy
@energy.setter
def energy(self, energy: float):
# Set the Energy attribute of radiating elements
for elem in self:
if (isinstance(elem, (elt.RFCavity, elt.Wiggler))
or elem.PassMethod.endswith('RadPass')):
elem.Energy = energy
# Set the energy attribute of the Lattice
# Use a numpy scalar to allow division by zero
# self._energy = numpy.array(energy, dtype=float)
self._energy = energy
@property
def cell_length(self) -> float:
"""Cell length (1 cell) [m]
See Also:
:py:meth:`circumference`.
"""
return self.get_s_pos(len(self))[0]
@property
def cell_revolution_frequency(self) -> float:
"""Revolution frequency for 1 cell [Hz]
See Also:
:py:meth:`revolution_frequency`.
"""
beta = self.beta
return beta * clight / self.cell_length
@property
def cell_harmnumber(self) -> float:
"""Harmonic number per cell
See Also:
:py:meth:`harmonic_number`.
"""
try:
return self._cell_harmnumber
except AttributeError:
raise AttributeError('harmonic_number undefined: '
'No cavity found in the lattice') from None
@property
def circumference(self) -> float:
"""Ring circumference (full ring) [m]
See Also:
:py:meth:`cell_length`.
"""
return self.periodicity * self.get_s_pos(len(self))[0]
@property
def revolution_frequency(self) -> float:
"""Revolution frequency (full ring) [Hz]
See Also:
:py:meth:`cell_revolution_frequency`.
"""
beta = self.beta
return beta * clight / self.circumference
@property
def particle(self) -> Particle:
"""Circulating particle"""
return self._particle
@particle.setter
def particle(self, particle: Union[str, Particle]):
if isinstance(particle, Particle):
self._particle = particle
else:
self._particle = Particle(particle)
[docs]
def set_wake_turnhistory(self):
"""Function to reset the shape of the turn history
in collective elements based on the number of slices,
turns and bunches
"""
for e in self:
if e.is_collective:
e.clear_history(ring=self)
[docs]
def set_fillpattern(self, bunches: Union[int, numpy.ndarray] = 1):
"""Function to generate the filling pattern lof the ring.
The filling pattern is computed as:
``bunches/numpy.sum(bunches)``
This function also generates the bunch spatial distribution
accessible with ``Lattice.bunch_spos``
Keyword Arguments:
bunches: integer or array of positive double or bool to define
the bunch distribution.
For scalar input, equidistant bunches are assumed.
``ring.harmonic_number`` has to be a multiple of
``bunches``.
For array input the condition
``len(bunches)==ring.harmonic_number`` is required.
(default=1, single bunch configuration).
"""
if isinstance(bunches, int):
if self.harmonic_number % bunches == 0:
fp = numpy.zeros(self.harmonic_number)
fp[::int(self.harmonic_number/bunches)] = 1
else:
raise AtError('Harmonic number has to be a '
'multiple of the scalar input '
'bunches')
elif numpy.isscalar(bunches):
raise AtError('Scalar input for bunches must be '
'an integer')
else:
bunches = bunches.astype(dtype=float, casting='safe',
copy=False)
assert len(bunches) == self.harmonic_number, \
'bunches array input has to be of shape ({0},)' \
.format(self.harmonic_number)
assert numpy.all(bunches >= 0.0), \
'bunches array can contain only positive numbers'
fp = bunches
self._fillpattern = fp/numpy.sum(fp)
self.set_wake_turnhistory()
@property
def fillpattern(self) -> numpy.ndarray:
"""Filling pattern describing the bunch relative
amplitudes such that ``sum(fillpattern)=1``
"""
return self._fillpattern
@fillpattern.setter
def fillpattern(self, value):
"""Filling pattern describing the bunch relative
amplitudes such that ``sum(fillpattern)=1``.
Calls the function ``Lattice.set_fillpattern``.
"""
self.set_fillpattern(value)
@property
def bunch_list(self) -> numpy.ndarray:
"""Indices of filled bunches"""
return numpy.flatnonzero(self._fillpattern)
[docs]
def get_beam_current(self):
return self._beam_current
[docs]
def set_beam_current(self, value, clear_history=True):
self._beam_current = value
if clear_history:
self.set_wake_turnhistory()
beam_current = property(get_beam_current, set_beam_current)
@property
def bunch_currents(self) -> numpy.ndarray:
"""Bunch currents [A]"""
return self.beam_current * \
self._fillpattern[self._fillpattern > 0]
@property
def bunch_spos(self) -> numpy.ndarray:
"""Bunch position around the ring [m]"""
try:
circ = self.beta * clight * \
self.harmonic_number/self.rf_frequency
except AtError:
circ = self.circumference
bs = circ/len(self._fillpattern)
allpos = bs*numpy.arange(len(self._fillpattern))
return allpos[self._fillpattern > 0]
@property
def nbunch(self) -> int:
"""Number of bunches"""
return numpy.count_nonzero(self._fillpattern)
@property
def harmonic_number(self) -> int:
"""Ring harmonic number (full ring)
See Also:
:py:meth:`cell_harmnumber`.
"""
try:
return int(self.periodicity * self._cell_harmnumber)
except AttributeError:
raise AttributeError('harmonic_number undefined: '
'No cavity found in the lattice') from None
@harmonic_number.setter
def harmonic_number(self, value):
cell_h = float(value) / self.periodicity
# check on ring
if value-round(value) != 0:
raise AtError('harmonic number ({}) must be integer'.format(value))
# check on cell
# if cell_h-round(cell_h) != 0:
# raise AtError('harmonic number ({}) must be a multiple of {}'
# .format(value, int(self.periodicity)))
self._cell_harmnumber = cell_h
if len(self._fillpattern) != value:
warn(AtWarning('Harmonic number changed, resetting fillpattern to '
'default (single bunch)'))
self.set_fillpattern()
@property
def gamma(self) -> float:
r"""Relativistic :math:`\gamma` of the particles"""
rest_energy = self.particle.rest_energy
if rest_energy == 0.0:
rest_energy = e_mass
return float(self.energy / rest_energy)
@property
def beta(self) -> float:
r"""Relativistic :math:`\beta` of the particles"""
rest_energy = self.particle.rest_energy
if rest_energy == 0.0:
return 1.0
else:
gamma = float(self.energy / rest_energy)
return math.sqrt(1.0 - 1.0/gamma/gamma)
# noinspection PyPep8Naming
@property
def BRho(self) -> float:
"""Magnetic rigidity [T.m]"""
rest_energy = self.particle.rest_energy
if rest_energy == 0.0:
rest_energy = e_mass
return math.sqrt(self.energy**2 - rest_energy**2)/clight
@property
def is_6d(self) -> bool:
"""True if at least one element modifies the beam momentum
See Also:
:py:meth:`enable_6d`, :py:meth:`disable_6d`.
"""
try:
return self._radiation
except AttributeError:
radiate = False
for elem in self:
if elem.longt_motion:
radiate = True
break
# noinspection PyAttributeOutsideInit
self._radiation = radiate
return radiate
@property
def is_collective(self) -> bool:
""":py:obj:`True` if any element involves collective effects"""
for elem in self:
if elem.is_collective:
return True
return False
@property
def has_cavity(self) -> bool:
""":py:obj:`True` if the lattice contains an active
:py:class:`RFCavity`
"""
for elem in self:
if elem.PassMethod.endswith('CavityPass'):
return True
return False
# noinspection PyShadowingNames
[docs]
def modify_elements(self, elem_modify: Callable,
copy: Optional[bool] = True, **kwargs):
"""Modify selected elements, in-place or in a lattice copy
Parameters:
elem_modify : element selection function.
If ``elem_modify(elem)`` returns :py:obj:`None`, the element is
unchanged. Otherwise, ``elem_modify(elem)`` must return a
dictionary of attribute name and values, to be set to elem.
copy: If True, return a shallow copy of the lattice.
Only the modified elements are copied.
If False, the modification is done in-place
Returns:
newring: New lattice if copy is :py:obj:`True`, :py:obj:`None`
if copy is :py:obj:`False`
Keyword Arguments:
"""
def lattice_modify(**kws):
"""Modifies the Lattice with elements modified by elem_modify"""
radiate = False
for elem in self:
attrs = elem_modify(elem)
if attrs is not None:
elem.update(attrs)
if elem.longt_motion:
radiate = True
self._radiation = radiate
self.update(kws)
def lattice_copy(params):
"""Custom iterator for the creation of a new lattice"""
radiate = False
for elem in self:
attrs = elem_modify(elem)
if attrs is not None:
elem = elem.copy()
elem.update(attrs)
if elem.longt_motion:
radiate = True
yield elem
params['_radiation'] = radiate
if copy:
return Lattice(lattice_copy, iterator=self.attrs_filter, **kwargs)
else:
lattice_modify(**kwargs)
def _set_6d(self, enable: bool, *args, **kwargs):
"""Set the lattice radiation state"""
def lattice_modify():
"""Modifies the Lattice in place"""
radiate = False
for elem in self:
new_pass = getpass(elem)
if new_pass:
elem.set_longt_motion(enable, new_pass=new_pass, **vargs)
if elem.longt_motion:
radiate = True
self._radiation = radiate
self.update(kwargs)
def lattice_copy(params):
"""Custom iterator for the creation of a new lattice"""
radiate = False
for elem in self:
new_pass = getpass(elem)
if new_pass:
elem = elem.set_longt_motion(enable, new_pass=new_pass,
copy=True, **vargs)
if elem.longt_motion:
radiate = True
yield elem
params['_radiation'] = radiate
cp = kwargs.pop('copy', False)
if len(args) > 0:
def getpass(elem):
return 'auto' if isinstance(elem, args) else None
if not all(issubclass(cl, elt.LongtMotion) for cl in args):
raise TypeError("All arguments must be subclasses of"
" 'LongtMotion'")
if len(kwargs) > 0:
raise AtError('No keyword is allowed in this mode')
else:
def getpass(elem):
for eltype, psm in pass_table:
if isinstance(elem, eltype):
return psm
return None
def passm(key, eltype, def_pass):
if allset:
def_pass = all_pass
return eltype, kwargs.pop(key, def_pass)
# Look for global defaults
try:
all_pass = kwargs.pop('all_pass')
except KeyError:
allset = False
else:
allset = True
# Build table of PassMethods
pass_table = [passm(*defs) for defs in _DEFAULT_PASS[enable]]
vargs = dict(energy=self.energy) if enable else {}
if cp:
return Lattice(lattice_copy, iterator=self.attrs_filter, **kwargs)
else:
lattice_modify()
# noinspection PyShadowingNames,PyIncorrectDocstring
[docs]
def enable_6d(self, *args, **kwargs) -> Optional[Lattice]:
# noinspection PyUnresolvedReferences
r"""
enable_6d(elem_class[, elem_class]..., copy=False)
enable_6d(cavity_pass='auto'[, dipole_pass='auto']..., copy=False)
Turn longitudinal motion on. By default, turn on
radiation in dipoles and quadrupoles, turn on RF cavities, activates
collective effects and other elements acting on momentum.
Modify the lattice in-place or creates a new lattice, depending on the
``copy`` keyword argument.
**Syntax using positional arguments:**
Parameters:
elem_class: :py:class:`.LongtMotion` subclass.
Longitudinal motion is turned on for elements which are
instances of any given ``elem_class``.
In adition to single element classes, a few grouping classes are
available:
* :py:class:`.LongtMotion`: all elements possibly acting on
momentum,
* :py:class:`.Radiative`: default radiative elements:
:py:class:`.Dipole`, :py:class:`.Quadrupole`,
:py:class:`.Wiggler`,
* :py:class:`.Collective`: all elements dealing with collective
effects.
The default PassMethod conversion is used, as with the ``'auto'``
keyword value..
**No keyword except** ``copy`` **is allowed in this syntax.**
**Syntax using keyword arguments:**
Keyword arguments:
all_pass: PassMethod overloading the default
values for all elements (:py:obj:`None` or 'auto')
cavity_pass='auto': PassMethod set on cavities
dipole_pass='auto': PassMethod set on dipoles
quadrupole_pass='auto': PassMethod set on quadrupoles
wiggler_pass='auto': PassMethod set on wigglers
sextupole_pass=None: PassMethod set on sextupoles
octupole_pass=None: PassMethod set on octupoles
multipole_pass=None : PassMethod set on higher order
multipoles
collective_pass='auto': PassMethod set on collective effect
elements (:py:class:`.WakeElement`,...)
diffusion_pass='auto': PassMethod set on
:py:class:`.QuantumDiffusion`
copy=False: If :py:obj:`False`, the modification is done in-place,
If ``True``, return a shallow copy of the lattice. Only the
radiating elements are copied with PassMethod modified.
.. Caution::
a shallow copy means that all non-modified elements are shared
with the original lattice. Any further modification will
affect both lattices.
For PassMethod names, the convention is:
* :py:obj:`None`: No change
* 'auto': Use the default conversion (replace \*Pass by
\*RadPass)
* anything else: set as the new PassMethod
Examples:
>>> ring.enable_6d()
Modify `ring` in-place, turn cavities ON, turn synchrotron
radiation ON in Dipoles and Quadrupoles, turn collective effects
ON.
>>> ring.enable_6d(at.RFCavity, at.Radiative)
Modify `ring` in-place, turn cavities ON, turn synchrotron
radiation ON in dipoles and quadupoles.
>>> newring = ring.enable_6d(at.Collective, copy=True)
Returns a new lattice with collective effects turned ON and nothing
else changed
>>> newring = ring.enable_6d(all_pass=None, collective_pass='auto',
... copy=True)
Same as the previous example, using the keyword syntax.
See Also:
:py:meth:`disable_6d`, :py:attr:`is_6d`.
"""
return self._set_6d(True, *args, **kwargs)
# noinspection PyShadowingNames,PyIncorrectDocstring
[docs]
def disable_6d(self, *args, **kwargs) -> Optional[Lattice]:
# noinspection PyUnresolvedReferences
r"""
disable_6d(elem_class[, elem_class]... , copy=False)
disable_6d(cavity_pass='auto'[, dipole_pass='auto']..., copy=False)
Turn longitudinal motion off. By default, remove all longitudinal
motion.
Modify the lattice in-place or creates a new lattice, depending on the
``copy`` keyword argument.
**Syntax using positional arguments:**
Parameters:
elem_class: :py:class:`.LongtMotion` subclass.
Longitudinal motion is turned off for elements which are
instances of any given ``elem_class``.
In adition to single element classes, a few grouping classes are
available:
* :py:class:`.LongtMotion`: all elements possibly acting on
momentum,
* :py:class:`.Radiative`: default radiative elements:
:py:class:`.Dipole`, :py:class:`.Quadrupole`,
:py:class:`.Wiggler`,
* :py:class:`.Collective`: all elements dealing with collective
effects.
The default PassMethod conversion is used, as with the ``'auto'``
keyword value.
**No keyword except** ``copy`` **is allowed in this syntax.**
**Syntax using keyword arguments:**
Keyword arguments:
all_pass: PassMethod overloading the default
values for all elements (:py:obj:`None` or 'auto')
cavity_pass='auto': PassMethod set on cavities
dipole_pass='auto': PassMethod set on dipoles
quadrupole_pass=auto: PassMethod set on quadrupoles
wiggler_pass='auto': PassMethod set on wigglers
sextupole_pass='auto': PassMethod set on sextupoles
octupole_pass='auto': PassMethod set on octupoles
multipole_pass='auto': PassMethod set on higher order
multipoles
collective_pass='auto': PassMethod set on collective effect
elements (:py:class:`.WakeElement`,...)
diffusion_pass='auto': PassMethod set on
:py:class:`.QuantumDiffusion`
copy=False: If :py:obj:`False`, the modification is done in-place,
If ``True``, return a shallow copy of the lattice. Only the
radiating elements are copied with PassMethod modified.
.. Caution::
a shallow copy means that all non-modified elements are shared
with the original lattice. Any further modification will
affect both lattices.
For PassMethod names, the convention is:
* :py:obj:`None`: no change
* 'auto': Use the default conversion (replace \*RadPass by
\*Pass)
* anything else: set as the new PassMethod
Examples:
>>> ring.disable_6d()
Modify `ring` in-place, turn OFF everything affecting the
longitudinal momentum.
>>> ring.disable_6d(at.RFCavity)
Turn cavities OFF (nothing else modified).
>>> ring.disable_6d(all_pass=None, cavity_pass='auto')
Same as the previous example, but using the keyword syntax.
>>> newring = ring.disable_6d(cavity_pass=None, copy=True)
Return a new Lattice (shallow copy of `ring`) with everything
turned OFF except RF cavities.
>>> newring = ring.disable_6d(all_pass=None,
... sextupole_pass='DriftPass', copy=True)
Return a new Lattice (shallow copy of `ring`) with sextupoles
turned into Drifts (turned off) and everything else unchangedd.
See Also:
:py:meth:`enable_6d`, :py:attr:`is_6d`.
"""
return self._set_6d(False, *args, **kwargs)
[docs]
def sbreak(self, break_s, break_elems=None, **kwargs):
"""Insert elements at selected locations in the lattice
Parameters:
break_s: location or array of locations of breakpoints
break_elems: elements to be inserted at breakpoints (array of
elements as long as break_s or single element
duplicated as necessary). Default: Marker('sbreak')
Returns:
newring: A new lattice with new elements inserted at breakpoints
"""
def sbreak_iterator(_, itmk):
"""Iterate over elements and breaks where necessary"""
def next_mk():
"""Extract the next element to insert"""
try:
return next(itmk)
except StopIteration:
return sys.float_info.max, None
s_end = 0.0
# get the 1st insertion
smk, mk = next_mk()
# skip all insertions at negative break_s, if any
while smk < s_end:
smk, mk = next_mk()
for elem in self:
s_end += elem.Length
# loop over all insertions within the element
while smk < s_end:
frac = (s_end - smk) / elem.Length
if frac < 1.0: # breakpoint is within the element
el0, elem = elem.divide([1.0 - frac, frac])
yield el0
yield mk
smk, mk = next_mk()
yield elem
# set default insertion
if break_elems is None:
break_elems = elt.Marker('sbreak')
break_elems = numpy.reshape(break_elems, -1)
# Check element lengths
if not all(e.Length == 0 for e in break_elems):
warn(AtWarning(
"Inserting elements with length!=0 may change the lattice"))
# broadcast break_s and break_elems to arrays of same size
# and create an iterator over the elements to be inserted
iter_mk = zip(*numpy.broadcast_arrays(break_s, break_elems))
return Lattice(sbreak_iterator, iter_mk,
iterator=self.attrs_filter, **kwargs)
[docs]
def reduce(self, **kwargs) -> Lattice:
"""Removes all elements with an ``IdentityPass`` PassMethod and merges
compatible consecutive elements.
The "reduced" lattice has the same optics as the original one, but
fewer elements. Compatible elements must have the same ``PolynomA``,
``PolynomB`` and bending radius, so that the optics is preserved. But
magnet misalignments are not preserved, so this method should be
applied to lattices without errors.
Keyword Args:
keep (Refpts): Keep the selected elements, even with
``IdentityPass`` PassMethod. Default: keep :py:class:`.Monitor`
and :py:class:`.RFCavity` elements
"""
def reduce_filter(_, itelem):
try:
elem = next(itelem).copy()
except StopIteration:
return
for nxt in itelem:
try:
elem.merge(nxt)
except TypeError:
yield elem
elem = nxt.copy()
yield elem
kp = get_bool_index(self, lambda el: el.PassMethod != 'IdentityPass')
try:
keep = get_bool_index(self, kwargs.pop('keep'))
except KeyError:
keep = get_bool_index(self, checktype((elt.Monitor, elt.RFCavity)))
return Lattice(reduce_filter, self.select(kp | keep),
iterator=self.attrs_filter, **kwargs)
[docs]
def replace(self, refpts: Refpts, **kwargs) -> Lattice:
"""Return a shallow copy of the lattice replacing the selected
elements by a deep copy
Parameters:
refpts: element selector
"""
check = get_bool_index(self, refpts)
elems = (el.deepcopy() if ok else el for el, ok in zip(self, check))
return Lattice(elem_generator, elems,
iterator=self.attrs_filter, **kwargs)
# Obsolete methods kept for compatibility
[docs]
def radiation_on(self, *args, **kwargs) -> Optional[Lattice]:
"""Obsolete. Turn longitudinal motion on
The function name is misleading, since the function deals with
longitudinal motion in general.
For this reason **the method is obsolete** and replaced by
:py:meth:`.enable_6d`
See Also:
:py:meth:`.enable_6d`
"""
kwargs.update(
zip(('cavity_pass', 'dipole_pass', 'quadrupole_pass'), args))
return self._set_6d(True, **kwargs)
[docs]
def radiation_off(self, *args, **kwargs) -> Optional[Lattice]:
"""Obsolete. Turn longitudinal motion off
The function name is misleading, since the function deals with
longitudinal motion in general.
For this reason **the method is obsolete** and replaced by
:py:meth:`.disable_6d`
See Also:
:py:meth:`disable_6d`
"""
kwargs.update(
zip(('cavity_pass', 'dipole_pass', 'quadrupole_pass'), args))
return self._set_6d(False, **kwargs)
@property
def radiation(self) -> bool:
"""Obsolete (see :py:attr:`is_6d` instead)
:meta private:
"""
try:
return self._radiation
except AttributeError:
radiate = False
for elem in self:
if elem.longt_motion:
radiate = True
break
# noinspection PyAttributeOutsideInit
self._radiation = radiate
return radiate
[docs]
def lattice_filter(params, lattice):
"""Copy lattice parameters and run through all lattice elements
Parameters:
params: Dictionary of Lattice attributes
lattice: Input ``Lattice``
Yields:
lattice ``Elements``
"""
return lattice.attrs_filter(params, elem_generator, lattice)
# noinspection PyUnusedLocal
[docs]
def elem_generator(params, elems: Iterable[Element]) -> Iterable[Element]:
"""Run through all elements without any check
Parameters:
params: Dictionary of Lattice attributes
elems: Iterable of lattice ``Elements``
Yields:
lattice ``Elements``
"""
return elems
no_filter: Filter = elem_generator # provided for backward compatibility
[docs]
def type_filter(params, elems: Iterable[Element]) -> Generator[Element, None, None]:
"""Run through all elements and check element validity.
Analyse elements for radiation state
Parameters:
params: Dictionary of Lattice attributes
elems: Iterable of lattice ``Elements``
Yields:
lattice ``Elements``
"""
radiate = False
for idx, elem in enumerate(elems):
if isinstance(elem, Element):
if elem.longt_motion:
radiate = True
yield elem
else:
warn(AtWarning('item {0} ({1}) is not an AT element: '
'ignored'.format(idx, elem)))
params['_radiation'] = radiate
[docs]
def params_filter(params, elem_filter: Filter, *args) -> Generator[Element, None, None]:
"""Run through all elements, looking for energy and periodicity.
Remove the Energy attribute of non-radiating elements
Parameters:
params: Dictionary of Lattice attributes
elem_filter: Next ``Elements`` filter
args: Arguments forwarded to **elem_filter**
Yields:
lattice ``Elements``
The following keys in ``params`` are set:
* ``_length``
* ``periodicity``
* ``energy`` (optional)
* ``_frequency`` (optional)
* ``harmonic_number`` (optional)
energy is taken from:
1) The params dictionary
2) Cavity elements
3) Any other element
periodicity is taken from:
1) The params dictionary
2) Sum of the bending angles of magnets
"""
el_energies = []
thetas = []
cavities = []
cell_length = 0
for elem in elem_filter(params, *args):
if isinstance(elem, elt.RFCavity):
cavities.append(elem)
elif hasattr(elem, 'Energy'):
el_energies.append(elem.Energy)
del elem.Energy
if isinstance(elem, elt.Dipole):
thetas.append(elem.BendingAngle)
cell_length += getattr(elem, 'Length', 0.0)
yield elem
params['_length'] = cell_length
cav_energies = [el.Energy for el in cavities if hasattr(el, 'Energy')]
if cavities:
cavities.sort(key=lambda el: el.Frequency)
c0 = cavities[0]
params.setdefault('harmonic_number',
getattr(c0, 'HarmNumber', math.nan))
# params['_harmnumber'] = getattr(c0, 'HarmNumber', math.nan)
params['_frequency'] = getattr(c0, 'Frequency', None)
if 'energy' not in params:
energies = cav_energies or el_energies
if energies:
# Guess energy from the Energy attribute of the elements
energy = params.setdefault('energy', max(energies))
if min(energies) < max(energies):
warn(AtWarning('Inconsistent energy values, '
'"energy" set to {0}'.format(energy)))
if 'periodicity' not in params:
# Guess periodicity from the bending angles of the lattice
try:
nbp = 2.0 * numpy.pi / sum(thetas)
except ZeroDivisionError:
periodicity = 1
warn(AtWarning('No bending in the cell, set "Periodicity" to 1'))
else:
periodicity = int(round(nbp))
if abs(periodicity - nbp) > _TWO_PI_ERROR:
warn(AtWarning('Non-integer number of cells: '
'{0} -> {1}'.format(nbp, periodicity)))
params['periodicity'] = periodicity
Lattice.get_uint32_index = get_uint32_index
Lattice.get_bool_index = get_bool_index
Lattice.refcount = _refcount
Lattice.set_shift = set_shift
Lattice.set_tilt = set_tilt
Lattice.get_elements = get_elements
Lattice.get_s_pos = get_s_pos
Lattice.select = refpts_iterator
Lattice.get_value_refpts = get_value_refpts
Lattice.set_value_refpts = set_value_refpts
Lattice.get_geometry = get_geometry
