The residual of a spot is the observed reciprocal vector (beam and distance, the tilt where refined,
the module's move where placed) minus the predicted one (orientation, cell lengths), and the two
halves share no parameter block. AutoDiffCostFunction carried all 12 (up to 14) derivatives through
both halves; SpotCost differentiates each half on its own blocks (6-8 and 6 derivatives) and writes
the Jacobian blocks from them. Values and derivatives are the same numbers.
Replaying the dumped placement inputs of four multi-panel stills runs on one thread: identical
held-out residuals, beam, distance, cell and module shifts; single-thread time of the nine fits
(after the previous commit -> now): AGIPD 66.8 -> 37.4 s, MPCCD 111.8 -> 92.1 s, JF4M 79.8 -> 52.3 s,
JF16M 68.4 -> 43.1 s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015CeEGgpKdfkCTJb3YNMJcu
leonarski_fandClaude Opus 5.5
c83b949b69