GDAtools (version 1.0)

conc.ellipse: Adds concentration ellipses to a correspondence analysis graph.

Description

Adds concentration ellipses to the individuals factor map of a correspondence analysis.

Usage

conc.ellipse(resmca, var, sel = 1:length(levels(varb)), col = rainbow(length(sel)), 
axes = c(1, 2), cex = 0.2)

Details

This function has to be used after the cloud of individuals has been drawn.

References

Le Roux B. and Rouanet H., Multiple Correspondence Analysis, SAGE, Series: Quantitative Applications in the Social Sciences, Volume 163, CA:Thousand Oaks (2010).

Le Roux B. and Rouanet H., Geometric Data Analysis: From Correspondence Analysis to Stuctured Data Analysis, Kluwer Academic Publishers, Dordrecht (June 2004).

See Also

plot.speMCA, plot.csMCA, plot.multiMCA, plot.stMCA

Examples

## Performs specific MCA (excluding 'NA' categories) of 'Taste' example data set,
## plots the cloud of categories
## and adds concentration ellipses for gender variable
data(Taste)
mca <- speMCA(Taste[,1:11],excl=c(3,6,9,12,15,18,21,24,27,30,33))
plot(mca,type='i')
conc.ellipse(mca,Taste$Gender)

## Draws a blue concentration ellipse for men only
plot(mca,type='i')
conc.ellipse(mca,Taste$Gender,sel=1,col='blue')