Anderson–Darling test for normality with mean and sd estimated from the sample.
Statistic A² = −n − (1/n)·Σ(2i−1)[ln F(z₍ᵢ₎) + ln(1 − F(z₍ₙ₊₁₋ᵢ₎))]; the p-value uses the
D'Agostino & Stephens (1986) approximation on A² = A²(1 + 0.75/n + 2.25/n²) — the same as Minitab.
For A² > 13, pValue is reported as zero (statsmodels convention); this is not an exact probability.
Anderson–Darling test for normality with mean and sd estimated from the sample. Statistic A² = −n − (1/n)·Σ(2i−1)[ln F(z₍ᵢ₎) + ln(1 − F(z₍ₙ₊₁₋ᵢ₎))]; the p-value uses the D'Agostino & Stephens (1986) approximation on A² = A²(1 + 0.75/n + 2.25/n²) — the same as Minitab. For A² > 13, pValue is reported as zero (statsmodels convention); this is not an exact probability.