PotentialArray#
- class abtem.potentials.iam.PotentialArray(array, slice_thickness=None, extent=None, sampling=None, exit_planes=None, ensemble_axes_metadata=None, metadata=None)[source]#
Bases:
BasePotential
,FieldArray
The potential array represents slices of the electrostatic potential as an array. All other potentials build potential arrays.
- Parameters:
array (3D np.ndarray) – The array representing the potential slices. The first dimension is the slice index and the last two are the spatial dimensions.
slice_thickness (float) – The thicknesses of potential slices [Å]. If a float, the thickness is the same for all slices. If a sequence, the length must equal the length of the potential array.
extent (one or two float, optional) – Lateral extent of the potential [Å].
sampling (one or two float, optional) – Lateral sampling of the potential [1 / Å].
exit_planes (int or tuple of int, optional) – The exit_planes argument can be used to calculate thickness series. Providing exit_planes as a tuple of int indicates that the tuple contains the slice indices after which an exit plane is desired, and hence during a multislice simulation a measurement is created. If exit_planes is an integer a measurement will be collected every exit_planes number of slices.
ensemble_axes_metadata (list of AxesMetadata) – Axis metadata for each ensemble axis. The axis metadata must be compatible with the shape of the array.
metadata (dict) – A dictionary defining wave function metadata. All items will be added to the metadata of measurements derived from the waves.
- __init__(array, slice_thickness=None, extent=None, sampling=None, exit_planes=None, ensemble_axes_metadata=None, metadata=None)[source]#
Methods
__init__
(array[, slice_thickness, extent, ...])apply_func
(func, **kwargs)- rtype:
TypeVar
(T
, bound= ArrayObject)
apply_transform
(transform[, max_batch])Transform the wave functions by a given transformation.
build
([first_slice, last_slice, chunks, lazy])compute
([progress_bar, profiler, ...])Turn a lazy abTEM object into its in-memory equivalent.
copy
()Make a copy.
copy_to_device
(device)Copy array to specified device.
ensemble_blocks
([chunks])Split the ensemble into an array of smaller ensembles.
ensure_lazy
([chunks])Creates an equivalent lazy version of the array object.
expand_dims
([axis, axis_metadata])Expand the shape of the array object.
from_array_and_metadata
(array, ...)Creates array object from a given array and metadata.
from_zarr
(url[, chunks])Read wave functions from a hdf5 file.
generate_blocks
([chunks])Generate chunks of the ensemble.
generate_ensemble
([keepdims])Generate every member of the ensemble.
generate_slices
([first_slice, last_slice])Generate the slices for the potential.
get_from_metadata
(name[, broadcastable])get_items
(items[, keepdims])Index the array and the corresponding axes metadata.
lazy
([chunks])- rtype:
TypeVar
(T
, bound= ArrayObject)
match_grid
(other[, check_match])Match the grid to another object with a Grid.
max
([axis, keepdims, split_every])Maximum of array object over one or more axes.
mean
([axis, keepdims, split_every])Mean of array object over one or more axes.
min
([axis, keepdims, split_every])Minmimum of array object over one or more axes.
Rechunk to remove chunks across the base dimensions.
project
()Create a 2D array representing a projected image of the potential(s).
rechunk
(chunks, **kwargs)Rechunk dask array.
select_block
(index, chunks)Select a block from the ensemble.
set_ensemble_axes_metadata
(axes_metadata, axis)Sets the axes metadata of an ensemble axis.
show
([project])Show the potential projection.
squeeze
([axis])Remove axes of length one from array object.
std
([axis, keepdims, split_every])Standard deviation of array object over one or more axes.
sum
([axis, keepdims, split_every])Sum of array object over one or more axes.
tile
(repetitions)Tile the potential.
to_cpu
()Move the array to the host memory from an arbitrary source array.
Convert ArrayObject to a xarray DataArray.
to_gpu
([device])Move the array from the host memory to a gpu.
Convert ArrayObject to a Hyperspy signal.
Convert slices of the potential to a stack of images.
to_tiff
(filename, **kwargs)Write data to a tiff file.
to_zarr
(url[, compute, overwrite])Write data to a zarr file.
transmission_function
(energy)Calculate the transmission functions for each slice for a specific energy.
transmit
(waves[, conjugate])Transmit a wave function through a potential slice.
Attributes
Underlying array describing the array object.
List of AxisMetadata.
List of AxisMetadata for the base axes.
Number of base dimensions.
Shape of the base axes of the potential.
The device where the array is stored.
Datatype of array.
List of AxisMetadata of the ensemble axes.
Number of ensemble dimensions.
Shape of the ensemble axes of the underlying array.
The "exit planes" of the potential.
The "exit thicknesses" of the potential.
Extent of grid for each dimension in Ångstrom.
Number of grid points for each dimension.
Simulation grid.
True if array is complex.
True if array is lazy.
Metadata stored as a dictionary.
Number of frozen phonons in the ensemble of potentials.
Number of exit planes.
Number of projected potential slices.
Reciprocal-space sampling in reciprocal Ångstrom.
Grid sampling for each dimension in Ångstrom per grid point.
Shape of the underlying array.
The entrance and exit thicknesses of each slice [Å].
Slice thicknesses for each slice.
Thickness of the potential [Å].
- apply_transform(transform, max_batch='auto')#
Transform the wave functions by a given transformation.
- Parameters:
transform (ArrayObjectTransform) – The array object transformation to apply.
max_batch (int, optional) – The number of wave functions in each chunk of the Dask array. If ‘auto’ (default), the batch size is automatically chosen based on the abtem user configuration settings “dask.chunk-size” and “dask.chunk-size-gpu”.
- Returns:
transformed_array_object – The transformed array object.
- Return type:
- property array: ndarray | Array#
Underlying array describing the array object.
- property axes_metadata: AxesMetadataList#
List of AxisMetadata.
- property base_axes_metadata#
List of AxisMetadata for the base axes.
- property base_dims#
Number of base dimensions.
- property base_shape#
Shape of the base axes of the potential.
- compute(progress_bar=None, profiler=False, resource_profiler=False, **kwargs)#
Turn a lazy abTEM object into its in-memory equivalent.
- Parameters:
progress_bar (bool) – Display a progress bar in the terminal or notebook during computation. The progress bar is only displayed with a local scheduler.
profiler (bool) – Return Profiler class used to profile Dask’s execution at the task level. Only execution with a local is profiled.
resource_profiler (bool) – Return ResourceProfiler class is used to profile Dask’s execution at the resource level.
kwargs – Additional keyword arguments passes to dask.compute.
- copy()#
Make a copy.
- copy_to_device(device)#
Copy array to specified device.
- Parameters:
device (str) –
- Returns:
object_on_device
- Return type:
T
- property device: str#
The device where the array is stored.
- property dtype: base#
Datatype of array.
- property ensemble_axes_metadata#
List of AxisMetadata of the ensemble axes.
- 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_dims#
Number of ensemble dimensions.
- property ensemble_shape: tuple[int, ...]#
Shape of the ensemble axes of the underlying array.
- ensure_lazy(chunks='auto')#
Creates an equivalent lazy version of the array object.
- Parameters:
chunks (int or tuple or str) – How to chunk the array. See dask.array.from_array.
- Returns:
lazy_array_object – Lazy version of the array object.
- Return type:
ArrayObject or subclass of ArrayObject
- property exit_planes: tuple[int, ...]#
The “exit planes” of the potential. The indices of slices where a measurement is returned.
- property exit_thicknesses: tuple[float]#
The “exit thicknesses” of the potential. The thicknesses in the potential where a measurement is returned.
- expand_dims(axis=None, axis_metadata=None)#
Expand the shape of the array object.
- Parameters:
axis (int or tuple of ints) – Position in the expanded axes where the new axis (or axes) is placed.
axis_metadata (AxisMetadata or List of AxisMetadata, optional) – The axis metadata describing the expanded axes. Default is UnknownAxis.
- Returns:
expanded – View of array object with the number of dimensions increased.
- Return type:
ArrayObject or subclass of ArrayObject
- property extent: tuple[float] | tuple[float, float] | tuple[float, ...]#
Extent of grid for each dimension in Ångstrom.
- classmethod from_array_and_metadata(array, axes_metadata, metadata)#
Creates array object from a given array and metadata.
- Parameters:
array (array) – Complex array defining one or more 2D wave functions. The second-to-last and last dimensions are the wave function y- and x-axis, respectively.
axes_metadata (list of AxesMetadata) – Axis metadata for each axis. The axis metadata must be compatible with the shape of the array. The last two axes must be RealSpaceAxis.
metadata (
dict
) – A dictionary defining wave function metadata. All items will be added to the metadata of measurements derived from the waves. The metadata must contain the electron energy [eV].
- Returns:
wave_functions – The created wave functions.
- Return type:
- classmethod from_zarr(url, chunks='auto')#
Read wave functions from a hdf5 file.
- Return type:
TypeVar
(T
, bound= ArrayObject)
- urlstr
Location of the data, typically a path to a local file. A URL can also include a protocol specifier like s3:// for remote data.
- chunkstuple of ints or tuples of ints
Passed to dask.array.from_array(), allows setting the chunks on initialisation, if the chunking scheme in the on-disc dataset is not optimal for the calculations to follow.
- generate_blocks(chunks=1)#
Generate chunks of the ensemble.
- Parameters:
chunks (iterable of tuples) – Block sizes along each dimension.
- generate_ensemble(keepdims=False)#
Generate every member of the ensemble.
- Parameters:
keepdims (bool, opptional) – If True, all ensemble axes are left in the result as dimensions with size one. Default is False.
- Yields:
ArrayObject or subclass of ArrayObject – Member of the ensemble.
- generate_slices(first_slice=0, last_slice=None)#
Generate the slices for the potential.
- Parameters:
first_slice (int, optional) – Index of the first slice of the generated potential.
last_slice (int, optional) – Index of the last slice of the generated potential.
- Yields:
slices (generator of np.ndarray) – Generator for the array of slices.
- get_items(items, keepdims=False)#
Index the array and the corresponding axes metadata. Only ensemble axes can be indexed.
- Parameters:
items (int or tuple of int or slice) – The array is indexed according to this.
keepdims (bool, optional) – If True, all ensemble axes are left in the result as dimensions with size one. Default is False.
- Returns:
indexed_array – The indexed array object.
- Return type:
ArrayObject or subclass of ArrayObject
- property gpts: tuple[int] | tuple[int, int] | tuple[int, ...]#
Number of grid points for each dimension.
- property grid: Grid#
Simulation grid.
- property is_complex: bool#
True if array is complex.
- property is_lazy: bool#
True if array is lazy.
- match_grid(other, check_match=False)#
Match the grid to another object with a Grid.
- max(axis=None, keepdims=False, split_every=2)#
Maximum of array object over one or more axes. Only ensemble axes can be reduced.
- Parameters:
axis (int or tuple of ints, optional) – Axis or axes along which a maxima are calculated. The default is to compute the mean of the flattened array. If this is a tuple of ints, the maxima are calculated over multiple axes. The indicated axes must be ensemble axes.
keepdims (bool, optional) – If True, the reduced axes are left in the result as dimensions with size one. Default is False.
split_every (int) – Only used for lazy arrays. See dask.array.reductions.
- Returns:
reduced_array – The reduced array object.
- Return type:
ArrayObject or subclass of ArrayObject
- mean(axis=None, keepdims=False, split_every=2)#
Mean of array object over one or more axes. Only ensemble axes can be reduced.
- Parameters:
axis (int or tuple of ints, optional) – Axis or axes along which a means are calculated. The default is to compute the mean of the flattened array. If this is a tuple of ints, the mean is calculated over multiple axes. The indicated axes must be ensemble axes.
keepdims (bool, optional) – If True, the reduced axes are left in the result as dimensions with size one. Default is False.
split_every (int) – Only used for lazy arrays. See dask.array.reductions.
- Returns:
reduced_array – The reduced array object.
- Return type:
ArrayObject or subclass of ArrayObject
- property metadata#
Metadata stored as a dictionary.
- min(axis=None, keepdims=False, split_every=2)#
Minmimum of array object over one or more axes. Only ensemble axes can be reduced.
- Parameters:
axis (int or tuple of ints, optional) – Axis or axes along which a minima are calculated. The default is to compute the mean of the flattened array. If this is a tuple of ints, the minima are calculated over multiple axes. The indicated axes must be ensemble axes.
keepdims (bool, optional) – If True, the reduced axes are left in the result as dimensions with size one. Default is False.
split_every (int) – Only used for lazy arrays. See dask.array.reductions.
- Returns:
reduced_array – The reduced array object.
- Return type:
ArrayObject or subclass of ArrayObject
- no_base_chunks()#
Rechunk to remove chunks across the base dimensions.
- property num_configurations#
Number of frozen phonons in the ensemble of potentials.
- property num_exit_planes: int#
Number of exit planes.
- property num_slices: int#
Number of projected potential slices.
- project()#
Create a 2D array representing a projected image of the potential(s).
- Returns:
images – One or more images of the projected potential(s).
- Return type:
- rechunk(chunks, **kwargs)#
Rechunk dask array.
- chunksint or tuple or str
How to rechunk the array. See dask.array.rechunk.
- kwargs :
Additional keyword arguments passes to dask.array.rechunk.
- property reciprocal_space_sampling: tuple[float] | tuple[float, float] | tuple[float, ...]#
Reciprocal-space sampling in reciprocal Ångstrom.
- property sampling: tuple[float] | tuple[float, float] | tuple[float, ...]#
Grid sampling for each dimension in Ångstrom per grid point.
- 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.
- set_ensemble_axes_metadata(axes_metadata, axis)#
Sets the axes metadata of an ensemble axis.
- Parameters:
axes_metadata (AxisMetadata) – The new axis metadata.
axis (int) – The axis to set.
- property shape: tuple[int, ...]#
Shape of the underlying array.
- show(project=True, **kwargs)#
Show the potential projection. This requires building all potential slices.
- Parameters:
project (bool, optional) – Show the projected potential (True, default) or show all potential slices. It is recommended to index a subset of the potential slices when this keyword set to False.
kwargs – Additional keyword arguments for the show method of
Images
.
- property slice_limits: list[tuple[float, float]]#
The entrance and exit thicknesses of each slice [Å].
- property slice_thickness: tuple[float, ...]#
Slice thicknesses for each slice.
- squeeze(axis=None)#
Remove axes of length one from array object.
- Parameters:
axis (int or tuple of ints, optional) – Selects a subset of the entries of length one in the shape.
- Returns:
squeezed – The input array object, but with all or a subset of the dimensions of length 1 removed.
- Return type:
ArrayObject or subclass of ArrayObject
- std(axis=None, keepdims=False, split_every=2)#
Standard deviation of array object over one or more axes. Only ensemble axes can be reduced.
- Parameters:
axis (int or tuple of ints, optional) – Axis or axes along which a standard deviations are calculated. The default is to compute the mean of the flattened array. If this is a tuple of ints, the standard deviations are calculated over multiple axes. The indicated axes must be ensemble axes.
keepdims (bool, optional) – If True, the reduced axes are left in the result as dimensions with size one. Default is False.
split_every (int) – Only used for lazy arrays. See dask.array.reductions.
- Returns:
reduced_array – The reduced array object.
- Return type:
ArrayObject or subclass of ArrayObject
- sum(axis=None, keepdims=False, split_every=2)#
Sum of array object over one or more axes. Only ensemble axes can be reduced.
- Parameters:
axis (int or tuple of ints, optional) – Axis or axes along which a sums are performed. The default is to compute the mean of the flattened array. If this is a tuple of ints, the sum is performed over multiple axes. The indicated axes must be ensemble axes.
keepdims (bool, optional) – If True, the reduced axes are left in the result as dimensions with size one. Default is False.
split_every (int) – Only used for lazy arrays. See dask.array.reductions.
- Returns:
reduced_array – The reduced array object.
- Return type:
ArrayObject or subclass of ArrayObject
- property thickness: float#
Thickness of the potential [Å].
- tile(repetitions)#
Tile the potential.
- Parameters:
repetitions (two or three int) – The number of repetitions of the potential along each axis. NOTE: if three integers are given, the first represents the number of repetitions along the z-axis.
- Returns:
The tiled potential.
- Return type:
PotentialArray object
- to_cpu()#
Move the array to the host memory from an arbitrary source array.
- Return type:
TypeVar
(T
, bound= ArrayObject)
- to_data_array()#
Convert ArrayObject to a xarray DataArray.
- to_gpu(device='gpu')#
Move the array from the host memory to a gpu.
- Return type:
TypeVar
(T
, bound= ArrayObject)
- to_hyperspy()#
Convert ArrayObject to a Hyperspy signal.
- to_images()#
Convert slices of the potential to a stack of images.
- to_tiff(filename, **kwargs)#
Write data to a tiff file.
- Parameters:
filename (str) – The filename of the file to write.
kwargs – Keyword arguments passed to tifffile.imwrite.
- to_zarr(url, compute=True, overwrite=False, **kwargs)#
Write data to a zarr file.
- Parameters:
url (str) – Location of the data, typically a path to a local file. A URL can also include a protocol specifier like s3:// for remote data.
compute (bool) – If true compute immediately; return dask.delayed.Delayed otherwise.
overwrite (bool) – If given array already exists, overwrite=False will cause an error, where overwrite=True will replace the existing data.
kwargs – Keyword arguments passed to dask.array.to_zarr.
- transmission_function(energy)[source]#
Calculate the transmission functions for each slice for a specific energy.
- Parameters:
energy (float) – Electron energy [eV].
- Returns:
transmissionfunction – Transmission functions for each slice.
- Return type:
- transmit(waves, conjugate=False)[source]#
Transmit a wave function through a potential slice.
- Parameters:
waves (Waves) – Waves object to transmit.
conjugate (bool, optional) – If True, use the conjugate of the transmission function. Default is False.
- Returns:
transmission_function – Transmission function for the wave function through the potential slice.
- Return type: