# statsmodels.stats.contingency_tables.Table2x2¶

class statsmodels.stats.contingency_tables.Table2x2(table, shift_zeros=True)[source]

Analyses that can be performed on a 2x2 contingency table.

Parameters
tablearray_like

A 2x2 contingency table

shift_zerosbool

If true, 0.5 is added to all cells of the table if any cell is equal to zero.

Notes

The inference procedures used here are all based on a sampling model in which the units are independent and identically distributed, with each unit being classified with respect to two categorical variables.

Note that for the risk ratio, the analysis is not symmetric with respect to the rows and columns of the contingency table. The two rows define population subgroups, column 0 is the number of ‘events’, and column 1 is the number of ‘non-events’.

Methods

 from_data(data[, shift_zeros]) Construct a Table object from data. homogeneity([method]) Compare row and column marginal distributions. log_oddsratio_confint([alpha, method]) A confidence level for the log odds ratio. log_oddsratio_pvalue([null]) P-value for a hypothesis test about the log odds ratio. log_riskratio_confint([alpha, method]) A confidence interval for the log risk ratio. log_riskratio_pvalue([null]) p-value for a hypothesis test about the log risk ratio. oddsratio_confint([alpha, method]) A confidence interval for the odds ratio. oddsratio_pvalue([null]) P-value for a hypothesis test about the odds ratio. riskratio_confint([alpha, method]) A confidence interval for the risk ratio. riskratio_pvalue([null]) p-value for a hypothesis test about the risk ratio. summary([alpha, float_format, method]) Summarizes results for a 2x2 table analysis. symmetry([method]) Test for symmetry of a joint distribution. Assess independence for nominal factors. test_ordinal_association([row_scores, …]) Assess independence between two ordinal variables.

Properties

 chi2_contribs Returns the contributions to the chi^2 statistic for independence. cumulative_log_oddsratios Returns cumulative log odds ratios. cumulative_oddsratios Returns the cumulative odds ratios for a contingency table. fittedvalues Returns fitted cell counts under independence. independence_probabilities Returns fitted joint probabilities under independence. local_log_oddsratios Returns local log odds ratios. local_oddsratios Returns local odds ratios. log_oddsratio Returns the log odds ratio for a 2x2 table. log_oddsratio_se Returns the standard error for the log odds ratio. log_riskratio Returns the log of the risk ratio. log_riskratio_se Returns the standard error of the log of the risk ratio. marginal_probabilities Estimate marginal probability distributions for the rows and columns. oddsratio Returns the odds ratio for a 2x2 table. resid_pearson Returns Pearson residuals. riskratio Returns the risk ratio for a 2x2 table. standardized_resids Returns standardized residuals under independence.