plotnScree.Rd
\name{plotnScree}
\alias{plotnScree}
\title{ Scree Plot According to a nScree Object Class }
\description{
Plot a scree plot adding information about a non graphical \code{nScree} analysis.
}
\usage{
plotnScree(nScree,
legend = TRUE,
ylab = "Eigenvalues",
xlab = "Components",
main = "Non Graphical Solutions to Scree Test"
)
}
\arguments{
\item{nScree}{ Results of a previous \code{nScree} analysis }
\item{legend}{ Logical indicator of the presence or not of a legend }
\item{xlab}{ Label of the x axis (default to \code{"Component"}) }
\item{ylab}{ Label of the y axis (default to \code{"Eigenvalue"}) }
\item{main}{ Main title (default to \code{"Non Graphical Solutions to the Scree Test"}) }
}
\value{
Nothing returned.
}
\references{
Raiche, G., Riopel, M. and Blais, J.-G. (2006). \emph{Non graphical solutions for the Cattell's scree test}.
Paper presented at the International Annual meeting of the Psychometric Society, Montreal.
[\url{http://www.er.uqam.ca/nobel/r17165/RECHERCHE/COMMUNICATIONS/}]
}
\author{
Gilles Raiche \cr
Centre sur les Applications des Modeles de Reponses aux Items (CAMRI) \cr
Universite du Quebec a Montreal\cr
\email{raiche.gilles@uqam.ca}, \url{http://www.er.uqam.ca/nobel/r17165/}
}
\seealso{
\code{\link{plotuScree}},
\code{\link{nScree}},
\code{\link{plotParallel}},
\code{\link{parallel}}
}
\examples{
## INITIALISATION
data(dFactors) # Load the nFactors dataset
attach(dFactors)
vect <- Raiche # Use the second example from Buja and Eyuboglu
# (1992, p. 519, nsubjects not specified by them)
eigenvalues <- vect$eigenvalues # Extract the observed eigenvalues
nsubjects <- vect$nsubjects # Extract the number of subjects
variables <- length(eigenvalues) # Compute the number of variables
rep <- 100 # Number of replications for the parallel analysis
cent <- 0.95 # Centile value of the parallel analysis
## PARALLEL ANALYSIS (qevpea for the centile criterion, mevpea for the mean criterion)
aparallel <- parallel(var = variables,
subject = nsubjects,
rep = rep,
cent = cent)$eigen$qevpea # The 95 centile
## NOMBER OF FACTORS RETAINED ACCORDING TO DIFFERENT RULES
results <- nScree(eig = eigenvalues,
aparallel = aparallel
)
results
## PLOT ACCORDING TO THE nScree CLASS
plotnScree(results)
}
\keyword{ Graphics }