ca {dimensio}

Correspondence Analysis

Description

Computes a simple correspondence analysis based on the singular value decomposition.

Usage

ca(object, ...)

## S4 method for signature 'data.frame'
ca(object, rank = NULL, sup_row = NULL, sup_col = NULL)

## S4 method for signature 'matrix'
ca(object, rank = NULL, sup_row = NULL, sup_col = NULL)

Arguments

object

A m \times p numeric matrix or a data.frame.

...

Currently not used.

rank

An integer value specifying the maximal number of components to be kept in the results. If NULL (the default), min(m, p) - 1 components will be returned.

sup_row

A vector specifying the indices of the supplementary rows.

sup_col

A vector specifying the indices of the supplementary columns.

Value

A CA object.

Author(s)

N. Frerebeau

References

Greenacre, M. J. Theory and Applications of Correspondence Analysis. London: Academic Press, 1984.

Greenacre, M. J. Correspondence Analysis in Practice. Seconde edition. Interdisciplinary Statistics Series. Boca Raton: Chapman & Hall/CRC, 2007.

Lebart, L., Piron, M. and Morineau, A. Statistique exploratoire multidimensionnelle: visualisation et inférence en fouille de données. Paris: Dunod, 2006.

See Also

svd()

Other multivariate analysis: mca(), pca(), predict()

Examples

## Data from Lebart et al. 2006, p. 170-172
data("colours")

## The chi square of independence between the two variables
stats::chisq.test(colours)

## Compute correspondence analysis
X <- ca(colours)

## Plot rows
viz_rows(X, labels = TRUE)

## Plot columns
viz_columns(X, labels = TRUE)

## Get row coordinates
head(get_coordinates(X, margin = 1))

## Get column coordinates
head(get_coordinates(X, margin = 2))

## Get row distances to centroid
head(get_distances(X, margin = 1))

## Get row inertias
head(get_inertia(X, margin = 1))

## Get row contributions
head(get_contributions(X, margin = 1))

## Get eigenvalues
get_eigenvalues(X)