wassname b80d7778af Add rotation-free S-space adapter cores (antipasto family) ...

Replace antipasto's rotation/Cayley with a bounded 1+ELU gain and split the
S-space idea into four interpretable PiSSA-style cores (frozen U/S/Vh, small
trainable core):

- antipasto: S_eff = S*(1+ELU(coeff*g)). exp-bounded attenuation, linear
  amplification (constant gradient, no runaway). g=0 -> exact identity.
- antipasto_rot: keeps the block-Cayley rotation as a separate variant for
  cost comparison (its per-forward solve is the 72ms vs 36ms gap).
- antipasto_ablate: contractive (I - a c c^T) diag(S), eigenvalues in [0,1],
  cannot blow up. Optional cov_orient (CorDA) basis.
- antipasto_corda: covariance-oriented oblique projector P = Vh C^{-1/2}, the
  data-energy basis rather than the weight-gain basis. 1+ELU gain.

Add scripts/_cost.py + scripts/cost_report.py: one-row-per-variant cost table
(trainable params, peak GPU mem, fwd/bwd ms, added MACs/tok, group_init ms).
Wire all four into the benchmark, smoke test, and __init__ exports.

External review (DeepSeek-v4-pro, docs/reviews/) verified the math; acted on
its one real point (corda g now inits to zeros for exact identity).

Co-Authored-By: Claudypoo <noreply@anthropic.com>

2026-06-14 19:12:27 +08:00

..

papers

tidy, review

2026-04-27 07:03:24 +08:00

refs

Add reference-impl URLs to variant docstrings + V2 external review

2026-04-26 19:27:47 +08:00

reviews

Add rotation-free S-space adapter cores (antipasto family)

2026-06-14 19:12:27 +08:00

developer_guide.md

tidy

2026-04-27 07:12:56 +08:00