statsmodels.stats.contingency_tables.SquareTable

class statsmodels.stats.contingency_tables.SquareTable(table, shift_zeros=True)

Methods for analyzing a square contingency table.

Parameters:

tablearray_like

A square contingency table, or DataFrame that is converted to a square form.

shift_zerosbool

If True and any cell count is zero, add 0.5 to all values in the table.

Notes

These methods should only be used when the rows and columns of the table have the same categories. If table is provided as a Pandas DataFrame, the row and column indices will be extended to create a square table, inserting zeros where a row or column is missing. Otherwise the table should be provided in a square form, with the (implicit) row and column categories appearing in the same order.

Attributes:

chi2_contribs

Returns the contributions to the chi^2 statistic for independence.

The returned table contains the contribution of each cell to the chi^2 test statistic for the null hypothesis that the rows and columns are independent.

cumulative_log_oddsratios

Returns cumulative log odds ratios.

The cumulative log odds ratios for a contingency table with ordered rows and columns are calculated by collapsing all cells to the left/right and above/below a given point, to obtain a 2x2 table from which a log odds ratio can be calculated.

cumulative_oddsratios

Returns the cumulative odds ratios for a contingency table.

See documentation for cumulative_log_oddsratio.

fittedvalues

Returns fitted cell counts under independence.

The returned cell counts are estimates under a model where the rows and columns of the table are independent.

independence_probabilities

Returns fitted joint probabilities under independence.

The returned table is outer(row, column), where row and column are the estimated marginal distributions of the rows and columns.

local_log_oddsratios

Returns local log odds ratios.

The local log odds ratios are the log odds ratios calculated for contiguous 2x2 sub-tables.

local_oddsratios

Returns local odds ratios.

See documentation for local_log_oddsratios.

marginal_probabilities

Estimate marginal probability distributions for the rows and columns.

rowndarray

Marginal row probabilities

colndarray

Marginal column probabilities

resid_pearson

Returns Pearson residuals.

The Pearson residuals are calculated under a model where the rows and columns of the table are independent.

standardized_resids

Returns standardized residuals under independence.

Methods

from_data(data[, shift_zeros])	Construct a Table object from data.
homogeneity([method])	Compare row and column marginal distributions.
summary([alpha, float_format])	Produce a summary of the analysis.
symmetry([method])	Test for symmetry of a joint distribution.
test_nominal_association()	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.
marginal_probabilities	Estimate marginal probability distributions for the rows and columns.
resid_pearson	Returns Pearson residuals.
standardized_resids	Returns standardized residuals under independence.