Diffractometer#

Diffractometers are built as a subclass of DiffractometerBase(), adding a variety of positioners as ophyd Components. In an instance of that subclass, user sets backend_solver by calling solver_factory(). In this call, the user specifies the solver, the geometry, and defines which Components (of the diffractometer) are to be used as pseudos and reals. The backend implements forward(), inverse(), and all related support, for only the pseudos and reals that are identified.

Parts of DiffractometerBase#

A DiffractometerBase object has several parts:

The DiffractometerBase() class should be a thin interface. Most real diffractometer capability should be provided in the Core() class (or one of its attributes, such as solver and sample)

Core-related methods and properties

`forward`(pseudos[, wavelength])	Compute real-space coordinates from pseudos (hkl -> angles).
`inverse`(reals[, wavelength])	Compute pseudo-space coordinates from reals (angles -> hkl).
`position`	Pseudo motor position namedtuple
`pseudo_axis_names`	Names of all the pseudo axes, in order of appearance.
`real_axis_names`	Names of all the real axes, in order of appearance.
`wh`([digits, full])	Concise report of the current diffractometer positions.

Sample-related methods and properties

`add_reflection`(pseudos[, reals, wavelength, ...])	Add a new reflection with this geometry to the selected sample.
`add_sample`(name, a[, b, c, alpha, beta, ...])	Add a new sample.
`sample`	Current sample object.
`samples`	Dictionary of samples.

Related methods and properties from other classes

`assign_axes`(pseudos, reals)	Designate attributes for use by the PseudoPositioner class.
`extra_axis_names`	Ordered list of any extra axis names (such as x, y, z).
`lattice`	Sample crystal lattice.
`refine_lattice`()	Refine the lattice parameters from 3 or more reflections.
`refine_lattice`(*reflections)	Return the sample lattice computed from 3 or more reflections.
`reflections`	Ordered dictionary of orientation reflections.
`set_solver`(name, geometry, **kwargs)	Create an instance of the backend Solver library and geometry.
`U`	Return the matrix, U, crystal orientation on the diffractometer.
`UB`	Return the crystal orientation matrix, UB.