spc_capability — SPC capability op

• データ種: signal → table

• 呼び出し: import fullseye as fs; fs.ledger.spc_capability(signal, lsl, usl, sigma=None) (実装を直接呼ぶなら import spc; spc.spc_capability(signal, lsl, usl, sigma=None)、台帳から引くなら opsspc.get("spc_capability"))

使い方

Process capability indices Cp and Cpk from measurements and spec limits.

`signal is a 1-D series of individual measurements; lsl / usl` are the

lower / upper specification limits (`lsl < usl). With the sample mean mu`

and standard deviation `sigma (sample std, ddof=1`, unless one is passed

in explicitly)::

Cp = (USL - LSL) / (6 sigma)

Cpk = min(USL - mu, mu - LSL) / (3 sigma)

Returns a dict with `mean / std / cp / cpk` and the echoed spec

limits and midpoint. `Cpk <= Cp` always, with equality exactly when the

process is centred (`mu` at the spec midpoint) — pinned in the tests.

Raises `ValueError`: a non-1-D / empty *signal*, fewer than two points

(no spread to estimate), `lsl >= usl`, non-finite limits, or a non-positive

standard deviation (a constant series has no capability to report).

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• poc_spc — py -3.11 examples/poc_spc.py

型が繋がる次の op(table を入力に取れる)

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同カテゴリ(capability)

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*Provenance: spc.py — SPC operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.