upxo.pxtal.twinned_simple_3d.steps.steps_orientation_assignment module

Orientation Assignment – Part J of the Twinned FCC walkthrough.

Assigns a crystal orientation (quaternion) to every grain in the host-allocated base structure, using EBSD-derived pools (parent-grain quaternions for hosts, a fallback pool – random by default – for non-hosts), resolving twin-pair conflicts per the selected mode. optimize_mapping() below runs many mode/seed combinations and scores each against a real EBSD pole-figure reference, keeping the best-matching assignment instead of a single, unscored run.

upxo.pxtal.twinned_simple_3d.steps.steps_orientation_assignment.assign_orientations(base, rg, parent_info, csl_label='S3  (twin)', ori_mode='conflict_free', rng_seed=42, connectivity=6, n_fallback=500, fallback_tc_info=None, fallback_apply_symmetry=None, mdf_n_bins=65, mdf_angle_max=65.0, pair_similarity_deg=10.0, max_retries=50, mrf_max_sweeps=20, mrf_eps_convergence=0.3, mrf_eps_quality=1.5, mrf_init_mode='mdf_analytical', mrf_kde_threshold=None, mrf_bilateral_symmetry=False, mrf_sa_t_start=5.0, mrf_sa_t_end=0.05)[source]

Runs one full orientation assignment. ori_mode=’conflict_free’ is the simplest/fastest mode – the mrf_*/pair_similarity_deg/ max_retries parameters only matter for the other modes (‘paired_pool’, ‘mdf_conditioned_pairs’, ‘mdf_analytical’, ‘mrf_gibbs’, ‘mrf_map’), but are always accepted regardless of which mode is active.

Returns:

  • OrientationAssigner3D (assigner – assigner.n_conflicts and its)

  • assigned quaternions/grain-orientation maps are the results; pass

  • this straight into steps_twin_generation’s functions.

upxo.pxtal.twinned_simple_3d.steps.steps_orientation_assignment.optimize_mapping(base, rg, parent_info, csl_label='S3  (twin)', selected=(('conflict_free', 5), ('paired_pool', 5)), base_seed=42, pole_family='100', resolution='Medium', unit_normalize=True, connectivity=6, n_fallback=500, fallback_tc_info=None, fallback_apply_symmetry=None, mdf_n_bins=65, mdf_angle_max=65.0, pair_similarity_deg=10.0, max_retries=50, mrf_max_sweeps=20, mrf_eps_convergence=0.3, mrf_eps_quality=1.5, mrf_init_mode='mdf_analytical', mrf_kde_threshold=None, mrf_bilateral_symmetry=False, mrf_sa_t_start=5.0, mrf_sa_t_end=0.05)[source]

Sweeps orientation-assignment mode/seed combinations, scoring each run’s synthetic host-grain pole figure against the real EBSD “pure parents” reference for csl_label (grains that, in the EBSD data, always host this CSL type’s twin and are never one themselves), via the interquartile range (IQR) of their cell-by-cell MUD-grid difference – smaller IQR means a tighter match. unit_normalize=True (default) compares pattern shape rather than absolute texture strength.

selected: an iterable of (mode, n_iterations) pairs. Available modes: ‘conflict_free’, ‘paired_pool’, ‘mdf_conditioned_pairs’, ‘mdf_analytical’, ‘mrf_gibbs’, ‘mrf_map’ – the last two are substantially slower and excluded from the default selection.

Every successful run is scored; the 10 lowest-IQR runs (across every swept mode) are re-run once more so their full OrientationAssigner3D objects are available for inspection – cheap relative to the full sweep, and avoids holding every single run’s assigner in memory at once.

Returns:

  • (records, top10) (records is every run’s score dict (‘mode’, ‘seed’,)

  • ’iqr’, ‘min’, ‘max’, ‘q25’, ‘q75’, ‘n_host’); top10 is the 10

  • lowest-IQR runs, each {**record, ‘assigner’ (OrientationAssigner3D},)

  • ranked ascending (index 0 = best match) – top10[0][‘assigner’] is

  • the recommended assignment to carry into Twin Generation.

upxo.pxtal.twinned_simple_3d.steps.steps_orientation_assignment.plot_optimize_mapping_distribution(records)[source]

Boxplot of IQR by mode across every run in records (from optimize_mapping()) – lower IQR means a tighter EBSD match; compares modes and run-to-run variability within a mode at a glance.

Return type:

(fig, ax)