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Hypothesis tests — Lodestar.Stats

Eighteen families of classical hypothesis test, at scipy.stats 1.18.1 parity. Arrays in, a statistic and a p-value out; nothing is fitted, so every entry point is static.

test	what it asks	entry point
Student / Welch t	do two samples have the same mean?	TTest
Mann-Whitney U	the same question, assuming no shape	MannWhitney
Wilcoxon signed-rank	the same, on paired measurements	Wilcoxon
χ²	do counts match an expected distribution, or are two factors independent?	ChiSquare
Fisher exact	the same for a 2×2 table, at any sample size	FisherExact
Kolmogorov-Smirnov	do two samples share a distribution?	KolmogorovSmirnov
one-way ANOVA	do several groups share one mean?	OneWayAnova
Kruskal-Wallis	the same, assuming no shape	KruskalWallis
Shapiro-Wilk	could this sample be normal?	ShapiroWilk
Bonferroni / BH / BY	how many of these results are chance?	MultipleComparisons
Pearson r	are these two variables related, along a line?	Pearson
Spearman rho	the same, along any rising or falling curve	Spearman
Kendall tau	the same, counted pair by pair	KendallTau
Levene	do several groups share one variance?	Levene
Bartlett	the same, assuming each group is normal	Bartlett
Friedman	do several treatments differ on the same subjects?	Friedman
binomial	is this proportion what it was said to be?	Binomial
Anderson-Darling	could this sample be normal?	AndersonDarling

Every family but six returns the same two numbers, TestResult; a t-test also carries its degrees of freedom (TTestResult), a contingency table also carries the table independence would have produced (Chi2ContingencyResult), Kolmogorov-Smirnov also carries where and in which direction the two samples parted furthest (KsResult), a Pearson correlation and a binomial test each carry what their intervals need (PearsonResult, BinomialResult), and Anderson-Darling carries the table its statistic is read against (AndersonResult).

result	carries	returned by
TestResult	a statistic, a p-value	twelve of the eighteen families
TTestResult	+ degrees of freedom, a confidence interval	TTest
Chi2ContingencyResult	+ degrees of freedom, the expected table	ChiSquare.Contingency
KsResult	+ where the gap was reached, and its sign	KolmogorovSmirnov
PearsonResult	+ a confidence interval for the correlation	Pearson
BinomialResult	+ a confidence interval for the proportion	Binomial
AndersonResult	+ the critical values and their significance levels	AndersonDarling

Eight small enums choose what a test asks, and how it answers when the exact and the approximate route disagree.

option	chooses
Alternative	which tail the p-value covers
Variance	whether an independent-samples t-test pools the two variances
Continuity	whether a discrete statistic's normal approximation gets the half-unit correction
ExactMethod	the exact null distribution, its normal approximation, or a choice between them
ZeroMethod	what Wilcoxon does with a pair whose difference is exactly zero
KendallVariant	which normalisation Kendall's tau carries; the p-value is the same either way
Center	which centre Levene's test measures each group's spread around
ProportionInterval	which interval a binomial proportion is reported with

The hypothesis-testing guide says which test answers which question, and the Python equivalence table maps each scipy call to its counterpart here.