2.2.1. prismatique.cbed.blank_unprocessed_pattern_signal

blank_unprocessed_pattern_signal(sample_specification, skip_validation_and_conversion=False)

Generate a blank unprocessed CBED pattern as a hyperspy signal.

This Python function may help users determine what postprocessing sequence they require to obtain postprocessed CBED intensity patterns with the desired pixel sizes, number of pixels, etc. For a discussion on postprocessing CBED patterns, see the documentation for the class prismatique.cbed.Params.

Parameters:

sample_specificationprismatique.sample.ModelParams | prismatique.sample.PotentialSliceSubsetIDs | prismatique.sample.SMatrixSubsetIDs | prismatique.sample.PotentialSliceAndSMatrixSubsetIDs

The simulation parameters specifying the sample model.

If sample_specification is of the type prismatique.sample.ModelParams, then sample_specifications specifies sample model parameters that are used to construct the model from scratch, i.e. the potential slices for each frozen phonon configuration subset are calculated from said model parameters. See the documentation for the classes prismatique.discretization.Params and prismatique.thermal.Params for discussions on potential slices and frozen phonon configuration subsets respectively. Note that of parameters stored in sample_specification, only the following are used:

• sample_specification

  • atomic_coords_filename

  • unit_cell_tiling

  • discretization_params

    • interpolation_factors

Otherwise, if sample_specification is an instance of the class prismatique.sample.PotentialSliceSubsetIDs, the class prismatique.sample.SMatrixSubsetIDs, or the class prismatique.sample.PotentialSliceAndSMatrixSubsetIDs, then sample_specification specifies a set of files, where each file stores either the pre-calculated potential slices or \(S\)-matrices for a frozen phonon configuration subset. See the documentation for the aforementioned classes for further discussions on specifying pre-calculated objects. See the documentation for the subpackage prismatique.stem for a discussion on \(S\)-matrices.

skip_validation_and_conversionbool, optional

If skip_validation_and_conversion is set to False, then validations and conversions are performed on the above parameters.

Otherwise, if skip_validation_and_conversion is set to True, no validations and conversions are performed on the above parameters. This option is desired primarily when the user wants to avoid potentially expensive validation and/or conversion operations.

Returns:

pattern_signalhyperspy._signals.signal2d.Signal2D

The blank unprocessed pattern, represented as a hyperspy signal. The convention used in prismatique is that, when converted to a hyperspy signal, the CBED pattern is visualized with the \(k_x\)-axis being the horizontal axis, increasing from left to right, and the \(k_y\)-axis being the vertical axis, increasing from bottom to top, both expressed in units of \(1/Å\).