ca: Simple correspondence analysis

Description Usage Arguments Details Value References See Also Examples

View source: R/ca.r

Description

Computation of simple correspondence analysis.

Usage

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ca(obj, ...)

## S3 method for class 'matrix'
ca(obj, nd = NA, suprow = NA, supcol = NA, 
   subsetrow = NA, subsetcol = NA, ...)

## S3 method for class 'data.frame'
ca(obj, ...)

## S3 method for class 'table'
ca(obj, ...)

## S3 method for class 'xtabs'
ca(obj, ...)

## S3 method for class 'formula'
ca(formula, data, ...)

Arguments

obj,formula

The function is generic, accepting various forms of the principal argument for specifying a two-way frequency table. Currently accepted forms are matrices, data frames (coerced to frequency tables), objects of class "xtabs" or "table" and one-sided formulae of the form ~ F1 + F2, where F1 and F2 are factors.

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.

data

A data frame against which to preferentially resolve variables in the formula

...

Other arguments passed to the ca.matrix method

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

N

The frequency table

References

Nenadic, O. and Greenacre, M. (2007). Correspondence analysis in R, with two- and three-dimensional graphics: The ca package. Journal of Statistical Software, 20 (3), http://www.jstatsoft.org/v20/i03/

Greenacre, M. (2007). Correspondence Analysis in Practice. Second Edition. London: Chapman & Hall / CRC. Blasius, J. and Greenacre, M. J. (1994), Computation of correspondence analysis, in Correspondence Analysis in the Social Sciences, pp. 53-75, London: Academic Press.

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, pp. 193-218.

See Also

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

Examples

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

# table method
haireye <- margin.table(HairEyeColor, 1:2)
haireye.ca <- ca(haireye)
haireye.ca
plot(haireye.ca)
# some plot options
plot(haireye.ca, lines=TRUE)
plot(haireye.ca, arrows=c(TRUE, FALSE))

 

ca documentation built on Jan. 24, 2020, 9:06 a.m.