ca: Simple correspondence analysis

Description

Computation of simple correspondence analysis.

Usage

ca(obj, nd = NA, suprow = NA, supcol = NA, subsetrow = NA, subsetcol = NA)

Arguments

obj

A two-way table of non-negative data, usually frequencies.

Number of dimensions to be included in the output; if NA the maximum possible dimensions are included.

suprow

Indices of supplementary rows.

supcol

Indices of supplementary columns.

subsetrow

Row indices of subset.

subsetcol

Column indices of subset.

Value

svSingular values
ndDimenson of the solution
rownamesRow names
rowmassRow masses
rowdistRow chi-square distances to centroid
rowinertiaRow inertias
rowcoordRow standard coordinates
rowsupIndices of row supplementary points
colnamesColumn names
colmassColumn masses
coldistColumn chi-square distances to centroid
colinertiaColumn inertias
colcoordColumn standard coordinates
colsupIndices of column supplementary points

Details

The function ca computes a simple correspondence analysis based on the singular value decomposition. The options suprow and supcol allow supplementary (passive) rows and columns to be specified. Using the options subsetrow and/or subsetcol result in a subset CA being performed.

References

Blasius, J. and Greenacre, M. J. (1994), Computation of correspondence analysis, in ``Correspondence Analysis in the Social Sciences'', pp. 53-75, Academic Press, London. Greenacre, M.J. and Pardo, R. (2006), Subset correspondence analysis: visualizing relationships among a selected set of response categories from a questionnaire survey. Sociological Methods and Research, 35, forthcoming.

Examples

Run this code

data(author)
ca(author)
plot(ca(author))

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