About the calls most fits use

A refinement in rietx usually needs seven calls: read the pattern, read the structure, build the instrument and its background, make a Refinement, fit, and plot. Everything else in the API serves a particular task.

The tiers below count which rietx functions the seven tutorials and three worked examples call, out of ten scripts. They count calls only, so reading a field such as RefinementResult.statistics does not appear, and neither does a result a notebook displays. The API reference lists every name.

This is how the second tutorial makes the first six of the seven calls:

import rietx as rx
from rietx.examples import examples_dir

data = rx.read_pattern(examples_dir() / "FAP.XRA")  # GSAS raw format
structure = rx.Structure.from_cif(examples_dir() / "fluorapatite.cif")
instrument = rx.Instrument.bragg_brentano(radiation="CuKa")
instrument.geometry.axial_sl.value = 0.02  # axial divergence
instrument.geometry.axial_hl.value = 0.02
instrument.background = rx.BackgroundChebyshev.with_terms(6)

ref = rx.Refinement(structure, instrument)
result = ref.fit(data, plan="mccusker_structural", two_theta_limits=(15, 130))

Every fit

Seven or more of the ten scripts make these calls.

Call	Scripts	What it does
rx.Refinement	10	holds the structure and instrument being refined
Refinement.fit	9	runs a plan of stages against a pattern
rx.Structure.from_cif	9	reads phases from a CIF
rx.Instrument.bragg_brentano	8	builds a flat-plate laboratory instrument
rx.BackgroundChebyshev.with_terms	8	builds a Chebyshev background with a given number of terms
RefinementResult.plot	8	draws the observed, calculated and difference curves
rx.read_pattern	7	reads a pattern file in any supported format

Often

Three or four of the ten make these calls.

Call	Scripts	What it does
RefinementResult.parameter	4	returns one refined parameter with its esd
PatternData.plot	4	draws a pattern before any fit
rx.diagnose	3	checks a raw pattern before a fit for humps, air scatter and lines from a stray wavelength
Refinement.summary	3	says whether a fit is finished, and why
Refinement.predict	3	calculates the pattern from the current models without refining
Refinement.checkout	3	returns the model to an earlier node of its history

For a particular task

Two of the ten scripts make each of these calls, or one does.

Task	Calls
Holding and tying parameters	Refinement.hold, Refinement.set_values, Refinement.tie_equal
Reading the history	RefinementTree.summary
Reading the report	Refinement.report, rx.build_report
Working in a project	rx.Project.create, Project.save, Project.fit
Choosing a background	rx.auto_background
A capillary instrument	rx.Instrument.debye_scherrer
An unknown cell	rx.pick_peaks, rx.fit_peaks, rx.index_pattern
Calibrating the instrument	rx.save_instrument_profile, rx.load_instrument_profile
A series of patterns	rx.refine_sequential
Exporting and drawing	Refinement.fitted_structure, Refinement.write_cif, rietx.viz.render_structure, rietx.viz.write_html