save & restore crystal orientation(s)

[prjemian]

• disk storage
• as part of bluesky run

[prjemian]

In a bluesky run using (original) hklpy, orientation is saved in a descriptor document.

[prjemian]

e4cv.operator.configuration._asdict() returns configuration as a dict: https://github.com/prjemian/hklpy2/blob/c26728dd33e3c9b701237dce8e3c0c067dbc1b03/hklpy2/operations/configure.py#L45-L63

Such as (default settings):

In [14]: e4cv.operator.configuration._asdict()
Out[14]: 
{'_header': {'datetime': '2025-01-13 11:58:35.936333',
  'energy_units': 'keV',
  'energy': 12.398419843856837,
  'hklpy2_version': '0.0.25.dev91+gc26728d',
  'python_class': 'SimulatedE4CV',
  'source_type': 'X-ray',
  'wavelength_units': 'angstrom',
  'wavelength': 1.0},
 'name': 'e4cv',
 'geometry': 'E4CV',
 'axes': {'pseudo_axes': ['h', 'k', 'l'],
  'real_axes': ['omega', 'chi', 'phi', 'tth'],
  'axes_xref': {'h': 'h',
   'k': 'k',
   'l': 'l',
   'omega': 'omega',
   'chi': 'chi',
   'phi': 'phi',
   'tth': 'tth'},
  'extra_axes': {}},
 'sample_name': 'sample',
 'samples': {'sample': {'name': 'sample',
   'lattice': {'a': 1,
    'b': 1,
    'c': 1,
    'alpha': 90.0,
    'beta': 90.0,
    'gamma': 90.0},
   'reflections': {},
   'reflections_order': [],
   'U': [[1, 0, 0], [0, 1, 0], [0, 0, 1]],
   'UB': [[1, 0, 0], [0, 1, 0], [0, 0, 1]],
   'digits': 4}},
 'constraints': {'omega': {'label': 'omega',
   'low_limit': -180.0,
   'high_limit': 180.0,
   'class': 'LimitsConstraint'},
  'chi': {'label': 'chi',
   'low_limit': -180.0,
   'high_limit': 180.0,
   'class': 'LimitsConstraint'},
  'phi': {'label': 'phi',
   'low_limit': -180.0,
   'high_limit': 180.0,
   'class': 'LimitsConstraint'},
  'tth': {'label': 'tth',
   'low_limit': -180.0,
   'high_limit': 180.0,
   'class': 'LimitsConstraint'}},
 'solver': {'name': 'hkl_soleil',
  'version': '5.0.0.3512',
  'mode': 'bissector',
  'description': "HklSolver(name='hkl_soleil', version='5.0.0.3512', geometry='E4CV', engine_name='hkl', mode='bissector')",
  'real_axes': ['omega', 'chi', 'phi', 'tth'],
  'engine': 'hkl'}}

[prjemian]

File-based save/restore exists: https://github.com/prjemian/hklpy2/blob/c26728dd33e3c9b701237dce8e3c0c067dbc1b03/hklpy2/operations/configure.py#L65 https://github.com/prjemian/hklpy2/blob/c26728dd33e3c9b701237dce8e3c0c067dbc1b03/hklpy2/operations/configure.py#L91

[prjemian]

Shortcut for e4cv.operator.configuration._asdict() is e4cv.operator._asdict()

[prjemian]

TODO: https://github.com/prjemian/hklpy2/blob/c26728dd33e3c9b701237dce8e3c0c067dbc1b03/hklpy2/operations/configure.py#L50

[prjemian]

In a bluesky run using (original) hklpy, orientation is saved in a descriptor document.

But this happens when (and only when) the diffractometer object is included as a detector in the scan.

Can we automate further? Perhaps recognize when a scan detector or positioner is a child Component of DiffractometerBase. Could this happen in a callback?

[prjemian]

It is not clear how we could have these two things together:

• autodetect the diffractometers involved in the plan
• write the configuration to the start document's metadata

An alternative is to build a preprocessor that knows which diffractometers to report, then have that write the configuration to the start document's metadata of every run.