SSM-AI – Lens Calibration Quickstart (3.5)

Pick Unit and c in minutes. Reproducible and stamped.

3.5 Lens calibration quickstart (2 minutes, reproducible)
Goal. Choose Unit and c so tanh(c*e) is informative (not saturated, not tiny), then freeze them in a manifest for apples-to-apples comparison.

Protocol (declare in manifest).

  1. Sample. Collect recent items’ raw terms (no PII).
  2. Compute provisional contrast.
e_raw := ( SUM alpha_i * P_i - SUM beta_j * N_j )

  1. Set Unit (normalize to dimensionless e).
q := median(|e_raw|)
Unit := max(q, 1e-6)
e := e_raw / Unit

  1. Set c (single gain knob).
# start
c := 1.0

# adjust by distribution of |a| = |tanh(c*e)|
if fraction(|a| > 0.9) > 0.10:  c := 0.7 * c
if fraction(|a| < 0.1) > 0.70:  c := 1.3 * c

  1. Freeze. Stamp Unit, c, alpha/beta in the manifest and reuse across vendors.

Lane mapping (reference).

a_in  := tanh( -c * e_in )
a_out := tanh( +c * e_out )

Chooser & zero-evidence guard (normative).

U_in  := SUM w_i * atanh(a_in_i)
V_out := SUM w_j * atanh(a_out_j)
W_in  := SUM w_i
RSI   := tanh( (V_out - U_in) / max(W_in, eps_w) )   # eps_w = 1e-12
if W_in == 0: RSI := 0; band := "A0"; reason := "insufficient_evidence"

Sanity metrics (log once/day).

saturation_rate := mean( |a| > 0.9 )
dead_zone_rate  := mean( |a| < 0.1 )
drift_watch     := (median_RSI, band_histogram)

QA checklist (pass/fail).
Clamps applied: a_c := clamp(a, -1+eps_a, +1-eps_a) before any atanh.
Unit stability: recomputing Unit shifts bands < 1 step on a holdout slice.
No-evidence path: W_in == 0RSI = 0, band A0, reason recorded.
Determinism: same manifest ⇒ identical a, RSI, band on replay.

One-line takeaway. Normalize with Unit, set a single gain c, verify distribution health, then freeze and stamp—consistent lanes, comparable RSI, reproducible audits.


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