crosstabs: Crosstabulation of two variables

In s20x: Functions for University of Auckland Course STATS 201/208 Data Analysis

Crosstabulation of two variables

Description

Produces a 2-way table of counts and the corresponding chi-square test of independence or homogeneity.

Usage

crosstabs(formula, data)

Arguments

formula	a symbolic description of the model to be fit: ~ fac1 + fac2; where fac1 and fac2 are vectors to be crosstabulated and treated internally as factors.
data	an optional data frame containing the variables in the model.

Value

Invisibly returns an object of class ct.20x, which is a list containing the following components:

row.props	a matrix of row proportions, i.e. cell counts divided by row marginals.
col.props	a matrix of column proportions, i.e. cell counts divided by column marginals.
whole.props	a matrix of whole-table proportions.
Totals	a matrix containing the cell counts and the marginal totals.
exp	a matrix of expected counts from the chi-square calculation.
chi	a matrix of cell contributions to the chi-square statistic.

Note

This is a legacy teaching helper retained for compatibility with older course material. New code should usually prefer table() and chisq.test() directly, or a purpose-built teaching wrapper.

Examples

##body image data:
data(body.df)
crosstabs(~ ethnicity + married, body.df)

s20x documentation built on July 1, 2026, 9:06 a.m.