A series of one file per image was laid out end to end: the rotation start came
from the first file and the step from the difference between the first two, so a
series with frames missing came out compressed - one 179.8 degree deposited sweep
of 1108 files out of 1800 was read as 111 degrees, and every frame past the first
gap was analysed at the wrong spindle angle. Indexing then found a lattice that
took 4% of the validation spots, and two other gapped series aborted outright
with "it is not this crystal's lattice".
Every one of these formats writes each image's own start angle in its own header,
so the sweep is fully recoverable. The new reader/SweepLayout places each frame at
the slot its own angle puts it in and leaves a missing frame as a gap - a slot with
no file, which ReadRawImage reports as nothing to read, which every image loop in
the pipeline already passes over. The goniometer's start + increment * image_number
is then the true angle of every image, and the sweep range, the per-10-degree
delta-CC1/2 batches and the sweep-quality ledger all read the rotation the headers
describe. The rotation step is the smallest move between two frames that really are
adjacent, not the first pair.
The three readers shared this code by duplication; it is now written once. The same
place refuses what is not a sweep rather than averaging it into one: headers that
disagree about the detector distance, the beam centre, the wavelength or the
oscillation width, angles that do not sit on a single step (a folder of screening
shots), or two frames claiming the same angle - each naming the frames. A series
that does not turn at all is left exactly as it was.
A directory holding fewer files than its own numbering spans is also reported, with
both counts: that is the signal that a sweep was not unpacked or copied whole, which
otherwise shows up only as a resolution nobody can explain.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nW6FNRP1bBJJ8pfHiByAT
