fullseye

spc_xbar_r — SPC chart op

使い方

Shewhart Xbar-R control chart from subgroup measurements.

subgroups is a 2-D array of shape (m, n)m subgroups of n measurements each, 2 <= n <= 10 (the range chart is only calibrated for small subgroups). For each subgroup j the plotted statistics are the mean Xbar_j and the range R_j = max - min. The centre lines are the grand mean Xbarbar and the mean range Rbar, and with the ISO 8258 constants (A2, D3, D4) for that n::

xbar_ucl = Xbarbar + A2*Rbar   xbar_lcl = Xbarbar - A2*Rbar
r_ucl    = D4*Rbar             r_lcl    = D3*Rbar

Returns a dict (a “table”) with the per-subgroup xbar / r arrays, the six limits and three centre lines, the integer indices out_of_control of subgroups outside either chart, and in_control (True when that list is empty). The constants are fixed by n: for n=5 they are exactly A2=0.577, D3=0.000, D4=2.115 (pinned in the tests).

Raises ValueError: a non-2-D / empty subgroups, a subgroup size outside [2, 10], or non-finite / mislabelled input.

参考(サンプルデータ・文献)

実行できる例(この op を実際に呼ぶ検証済みサンプル)

型が繋がる次の op(table を入力に取れる)

同カテゴリ(chart)


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.