📦 WP-091d — refine(data): one rotated-box shape check¶
Research log · Phase 9 — Inference and generalization
WP-091d — one letter, and what it costs to change one¶
091c declined this merge and said why: the two validators' messages are matched by two test files, so removing the duplicate changes what an error says, and a refactor contracted to leave every existing test passing cannot also do that. Done as its own package the visibility is the point rather than the obstacle. _check_rboxes is deleted, rotated_iou guards through _check_2d, and tests/eval/test_dota_eval.py's match=r"must be \(K, 5\)" becomes r"boxes_a must be \(N, 5\)" — a stricter regex than the one it replaces, since it now pins the argument name as well as the shape. The other pinned message, in tests/data/test_rotated_geom.py, never moved: it was already the surviving spelling.
The letter itself was the only real question. rotated_iou's signature does distinguish the two operands — boxes_a is (M, 5), boxes_b is (N, 5), and the result is (M, N), so the distinction is load-bearing in the docstring. It is not load-bearing in the guard: each operand has to satisfy one and the same predicate, and a rejection message that spelled one of them K named a difference the check never tested. N reads as "some row count" in every message the module raises, which is what a shape rejection is actually saying.
What made the merge safe is narrow and worth stating, because the neighbouring lookalike fails it. The two conditions were character-identical — ndim != 2 or shape[1] != 5 — so nothing but the string changed. losses/probiou.py's guard passes arbitrary leading dimensions, and folding that one in would tighten a live contract rather than dedupe a message; that is 091e, and it is a different package for that reason and not for tidiness.