Three follow-ups to the converging scale loop, all on sweeps with a stretch the crystal barely
diffracted on:
- The sweep ledger's scale channel (and with it delta-CC1/2's "normal frame" test) and the
space-group search's scale floor measure a frame against the precision-weighted typical frame
G_ref (TypicalFrameScale) instead of the run median: on a sweep that spent most of its turn out
of the beam the median frame is itself a dead one, and every stretch then reads as typical. The
two collapse guards stay on the median on purpose - a frame that collapsed toward zero and was
not quite dropped has its fulls re-fitted with a scale of 1/G, a cubic mean is then theirs, and
the floor read against it dropped three quarters of every live frame's fulls (measured).
- delta-CC1/2's sigma-tau statistic enters each reflection with the information it carries (the
same per-frame factor as the CC1/2 weight), so a dead stretch, whose scaled-up noise flooded the
mean error variance of every mixed reflection and read as harm up to the 25% cap, now costs
about nothing and is left to the ledger.
- The scale loop's step test weighs each frame by its merge weight (its observations at its scale
squared): a dead frame's scale is fitted on noise and wanders by orders of magnitude every
iteration, carries nothing into the merge, is dropped after the loop, and must not hold the loop
open.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nW6FNRP1bBJJ8pfHiByAT
leonarski_fandClaude Fable 5.1
ddc7855900