gum_expanded — SPC uncertainty op

• Data kinds: table → table

• Call: import fullseye as fs; fs.ledger.gum_expanded(table, u='u', sensitivity='sensitivity', dof='dof', level=0.95, correlation=None, estimate=None, lower_bound=None, upper_bound=None) (to call the implementation directly, import spc; spc.gum_expanded(table, u='u', sensitivity='sensitivity', dof='dof', level=0.95, correlation=None, estimate=None, lower_bound=None, upper_bound=None); from the registry, opsspc.get("gum_expanded"))

Usage

Welch-Satterthwaite effective degrees of freedom, coverage factor k and expanded uncertainty U (`table`).

> The detailed description below is the original text — the summary and the headings are translated.

nu_eff = u_c^4 / sum_i (c_i u_i)^4 / nu_i U = k u_c, k = t_{p}(nu_eff)

★門にできる厳密な性質が 3 つある:

• 成分が 1 つだけなら `nu_eff == nu`(厳密)。

• `nu_eff >= min_i nu_i` が常に成り立つ。証明は

`sum u_i^4/nu_i <= (1/nu_min) sum u_i^4 <= (1/nu_min)(sum u_i^2)^2`。

有効自由度が最小の成分より小さくなったら計算が壊れている。

• すべての自由度が無限大なら `k` は正規分布の分位点へ収束する

(95 % で 1.959964)。

無限自由度(既知の定数など)は `numpy.inf` を入れる。

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_measurement_system_analysis — py -3.11 examples/poc_measurement_system_analysis.py

Ops the type connects to (they accept table as input)

msa_anova_table · msa_gauge_rr · msa_bias_linearity · msa_attribute_agreement · gum_standard_uncertainty · gum_propagate · gum_monte_carlo · gum_validate

Same category (uncertainty)

gum_standard_uncertainty · gum_propagate · gum_monte_carlo · gum_validate


*Provenance: spc.py — SPC operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

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