Step reference

Every registered pipeline step, grouped by what it does, with the arrays it reads, the arrays it writes, and the parameters you set in YAML.

For the auto-generated, source-linked docstrings see Analysis steps (API). For how steps fit into a full pipeline file, see the YAML pipeline guide.

The step contract

A step is a stateless function step(run, **kwargs) -> None. The run object is a shared blackboard: a step reads attributes off it, does its work, and writes results back as new attributes. The next step picks those up by name. Nothing is returned; everything flows through run.

So in this reference:

• Reads = the run attributes (and their shapes) a step expects to already exist.
• Writes = the run attributes it sets.
• Parameters = the keys you pass in the YAML step: block. on is almost always the attribute a step operates on.

A step that can't find its input (on missing, or the attribute is None) returns quietly and logs a status message rather than raising. This lets the same pipeline run on a parent that has no detector loaded (batched path) and on each batch that does.

Array shapes

The docs use a consistent vocabulary for array shapes:

Shape	Meaning
(shots, rows, cols)	3D detector, one frame per shot
(shots, pixels)	2D detector after one spatial axis is reduced
(shots,)	per-shot scalar or 1D key (IPM, delay, CCM energy)
(shots,) bool	shot mask (xray, laser, simultaneous)
(n_time_bins, pixels) or (n_time_bins,)	time-binned spectrum
(n_energy, pixels) or (n_energy,)	energy (CCM) binned spectrum
(n_time, n_energy[, pixels])	2D time+energy binned

Detector steps generally accept 2D or 3D and act on the shot axis (axis 0) or the last (dispersion) axis; each entry says which.

Naming conventions

Steps build output names from the input key plus a suffix describing the operation, so a chain reads left to right:

epix                                                  (loaded detector, 3D)
epix_ROI_1                                             (reduce_detector_spatial)
epix_ROI_1_simultaneous_laser                         (union_shots)
epix_ROI_1_simultaneous_laser_time_binned             (reduce_detector_temporal)
epix_ROI_1_simultaneous_laser_time_binned_normalized  (normalize_xes)

Each step's on is the previous step's output name.

All steps

Step	Group	Reads	Writes
load_run_keys	Loading	HDF5	named per-shot keys
load_detector	Loading	HDF5	3D detector
get_run_shot_properties	Loading	lightStatus	xray, laser, simultaneous
droplet_reconstruction	Loading	sparse HDF5	new_key 3D stack
filter_shots	Filtering	mask + key	overwrites mask
filter_detector_adu	Filtering	detector	overwrites on
filter_detector_variance	Filtering	3D detector	overwrites on + _variance_mask
hitfinding	Filtering	3D detector	overwrites on (fewer shots)
union_shots	Filtering	on + masks	new_key
separate_shots	Filtering	on + 2 masks	new_key
common_mode_correction	Detector	3D/2D detector	overwrites on
patch_pixels	Detector	detector	overwrites on
find_rotation_angle	Detector	3D/2D detector	<on>_angle
rotate_detector	Detector	3D/2D detector	overwrites on
apply_roi	Spatial	2D/3D detector	<on>_ROI_n (keeps spatial)
reduce_detector_spatial	Spatial	3D/2D detector	<on>_ROI_n (reduced)
reduce_detector_shots	Spatial	detector	<on>_reduced
time_binning	Binning	timing keys	time_bins, timing_bin_indices
make_ccm_axis	Binning	ccm	ccm_bins, ccm_energies
ccm_binning	Binning	ccm, ccm_bins	ccm_bin_indices
bin_uniques	Binning	scan var	scanvar_indices, scanvar_bins
make_energy_axis	Binning	detector shape	<name>_energy
reduce_detector_temporal	Binning	1D/2D + time indices	<on>_time_binned
reduce_detector_ccm	Binning	1D/2D/3D + ccm indices	<on>_energy_binned
reduce_detector_ccm_temporal	Binning	1D/2D + both indices	<on>_time_energy_binned
normalize_xes	Spectra	1D/2D spectrum	<on>_normalized
subtract_polynomial_background	Spectra	1D/2D spectrum	<on>_bkgsub
purge_keys	Utility	nothing	sets keys to None
combine_runs	Reduction	per-run binned data	results dict