The eden.py default formula S = ||x||²/⟨c,x⟩ was loosely labeled as
"biased optimal-S" throughout. On closer inspection that's imprecise:
the strict per-vector MSE-minimum is S* = ⟨c,x⟩/||c||² (textbook
least-squares; asymptotically → 1 for Lloyd-Max optimal centroids).
The eden.py default is a different formula, satisfying the inner-
product-preserving identity ⟨Sc, x⟩ = ||x||² per vector.
Empirical comparisons unaffected (we tested what eden.py ships).
Just the labeling. Added Terminology note in §4 with worked example
and credit to @amitport for surfacing it.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
