ca {ca}R Documentation

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.
nd 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.

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.

Value

sv Singular values
nd Dimenson of the solution
rownames Row names
rowmass Row masses
rowdist Row chi-square distances to centroid
rowinertia Row inertias
rowcoord Row standard coordinates
rowsup Indices of row supplementary points
colnames Column names
colmass Column masses
coldist Column chi-square distances to centroid
colinertia Column inertias
colcoord Column standard coordinates
colsup Indices of column supplementary points

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.

See Also

svd, plot.ca, plot3d.ca, summary.ca, print.ca

Examples

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

[Package ca version 0.21 Index]