Zernike#

class abtem.transfer.Zernike(center_hole_cutoff, phase_shift, semiangle_cutoff, energy=None, extent=None, gpts=None, sampling=None)[source]#

Bases: abtem.transfer.BaseAperture

Zernike aperture.

Parameters

center_hole_cutoff (float) – Cutoff semiangle of aperture hole [mrad].
phase_shift (float) – Phase shift of Zernike film [rad]
semiangle_cutoff (float) – The cutoff semiangle of the aperture [mrad].
energy (float, optional) – Electron energy [eV]. If not provided, inferred from the wave functions.
extent (float or two float, optional) – Lateral extent of wave functions [Å] in x and y directions. If a single float is given, both are set equal.
gpts (two ints, optional) – Number of grid points describing the wave functions.
sampling (two float, optional) – Lateral sampling of wave functions [1 / Å]. If ‘gpts’ is also given, will be ignored.

__init__(center_hole_cutoff, phase_shift, semiangle_cutoff, energy=None, extent=None, gpts=None, sampling=None)[source]#

Methods

`__init__`(center_hole_cutoff, phase_shift, ...)
`apply`(waves)	Apply the transform to the given waves.
`copy`()	Make a copy.
`ensemble_blocks`([chunks])	Split the ensemble into an array of smaller ensembles.
`generate_blocks`([chunks])	Generate chunks of the ensemble.
`match_grid`(other[, check_match])	Match the grid to another object with a Grid.
`select_block`(index, chunks)	Select a block from the ensemble.
`show`(**kwargs)
`to_diffraction_patterns`([max_angle, gpts])

Attributes

`accelerator`	Accelerator object describing the acceleration energy.
`angular_sampling`	The sampling in scattering angles of the transfer function [mrad].
`axes_metadata`	List of AxisMetadata.
`base_axes_metadata`	List of AxisMetadata of the base axes.
`base_shape`	Shape of the base axes.
`center_hole_cutoff`	Cutoff semiangle of aperture hole.
`distributions`
`energy`	Electron acceleration energy in electron volts.
`ensemble_axes_metadata`	Axes metadata describing the ensemble axes added to the waves when applying the transform.
`ensemble_shape`	The shape of the ensemble axes added to the waves when applying the transform.
`extent`	Extent of grid for each dimension in Ångstrom.
`gpts`	Number of grid points for each dimension.
`grid`	Simulation grid.
`in_place`	The array representing the waves may be modified in-place.
`metadata`	Metadata added to the waves when applying the transform.
`nyquist_sampling`	Nyquist sampling corresponding to the semiangle cutoff of the aperture [Å].
`phase_shift`	Phase shift of Zernike film.
`reciprocal_space_sampling`	Reciprocal-space sampling in reciprocal Ångstrom.
`sampling`	Grid sampling for each dimension in Ångstrom per grid point.
`semiangle_cutoff`	Semiangle cutoff of the aperture [mrad].
`shape`	Shape of the ensemble.
`wavelength`	Relativistic wavelength in Ångstrom.

property accelerator: abtem.core.energy.Accelerator#

Accelerator object describing the acceleration energy.

Return type: Accelerator

property angular_sampling: tuple[float, float]#

The sampling in scattering angles of the transfer function [mrad].

Return type: tuple[float, float]

apply(waves)#

Apply the transform to the given waves.

Parameters: array_object (ArrayObject) – The array object to transform.
Returns: transformed_array_object
Return type: ArrayObject

property axes_metadata: abtem.core.axes.AxesMetadataList#

List of AxisMetadata.

Return type: AxesMetadataList

property base_axes_metadata: list[abtem.core.axes.AxisMetadata]#

List of AxisMetadata of the base axes.

Return type: list[AxisMetadata]

property base_shape: tuple[int, ...]#

Shape of the base axes.

Return type: tuple[int, ...]

property center_hole_cutoff: float#

Cutoff semiangle of aperture hole.

Return type: float

copy()#: Make a copy.

property energy#: Electron acceleration energy in electron volts.

property ensemble_axes_metadata: list[abtem.core.axes.AxisMetadata]#

Axes metadata describing the ensemble axes added to the waves when applying the transform.

Return type: list[AxisMetadata]

ensemble_blocks(chunks=None)#

Split the ensemble into an array of smaller ensembles.

Parameters: chunks (iterable of tuples) – Block sizes along each dimension.
Return type: Array

property ensemble_shape#: The shape of the ensemble axes added to the waves when applying the transform.

property extent: tuple[float] | tuple[float, float] | tuple[float, ...]#

Extent of grid for each dimension in Ångstrom.

Return type: tuple[float] | tuple[float, float] | tuple[float, …]

generate_blocks(chunks=1)#

Generate chunks of the ensemble.

Parameters: chunks (iterable of tuples) – Block sizes along each dimension.

property gpts: tuple[int] | tuple[int, int] | tuple[int, ...]#

Number of grid points for each dimension.

Return type: tuple[int] | tuple[int, int] | tuple[int, …]

property grid: abtem.core.grid.Grid#

Simulation grid.

Return type: Grid

property in_place: bool#

The array representing the waves may be modified in-place.

Return type: bool

match_grid(other, check_match=False)#: Match the grid to another object with a Grid.

property metadata#: Metadata added to the waves when applying the transform.

property nyquist_sampling: float#

Nyquist sampling corresponding to the semiangle cutoff of the aperture [Å].

Return type: float

property phase_shift: float#

Phase shift of Zernike film.

Return type: float

property reciprocal_space_sampling: tuple[float] | tuple[float, float] | tuple[float, ...]#

Reciprocal-space sampling in reciprocal Ångstrom.

Return type: tuple[float] | tuple[float, float] | tuple[float, …]

property sampling: tuple[float] | tuple[float, float] | tuple[float, ...]#

Grid sampling for each dimension in Ångstrom per grid point.

Return type: tuple[float] | tuple[float, float] | tuple[float, …]

select_block(index, chunks)#

Select a block from the ensemble.

Parameters

index (tuple of ints) – Index of selected block.
chunks (iterable of tuples) – Block sizes along each dimension.

property semiangle_cutoff#: Semiangle cutoff of the aperture [mrad].

property shape#: Shape of the ensemble.

property wavelength#: Relativistic wavelength in Ångstrom.