Plot the successive eigen values for a scree test

Cattell's scree test is one of most simple ways of testing the number of components or factors in a correlation matrix. Here we plot the eigen values of a correlation matrix as well as the eigen values of a factor analysis.

scree(rx,factors=TRUE,pc=TRUE,main="Scree plot",hline=NULL,add=FALSE)
VSS.scree(rx, main = "scree plot")

Arguments

rx	a correlation matrix or a data matrix. If data, then correlations are found using pairwise deletions.
factors	If true, draw the scree for factors
pc	If true, draw the scree for components
hline	if null, draw a horizontal line at 1, otherwise draw it at hline (make negative to not draw it)
main	Title
add	Should multiple plots be drawn?

Details

Among the many ways to choose the optimal number of factors is the scree test. A better function to show the scree as well as compare it to randomly parallel solutions is found found in fa.parallel

References

http://personality-project.org/r/vss.html

See also

fa.parallel VSS.plot, ICLUST, omega

Examples

scree(attitude)
#VSS.scree(cor(attitude)