eigenBootParallel {nFactors}R Documentation

Bootstrapping of the Eigenvalues From a Data Frame

Description

The eigenBootParallel function samples observations from a data.frame to produces correlation or covariance matrix from which eigenvalues are computed. The function returns statistics about these bootstrapped eigenvalues. Their means or their quantile could be used later to replace the eigenvalues inputed to a parallel analysis. The eigenBootParallel can also computes random eigenvalues from empirical data by columns permutation (Buja and Eyuboglu, 1992).

Usage

 eigenBootParallel(x, quantile=0.95, nboot=30, option="permutation",
                   cor=TRUE, model="components", ...)
 

Arguments

x data.frame: data from which a correlation matrix will be obtained
quantile numeric: eigenvalues quantile that will be reported
nboot numeric: number of bootstrap samples
option character: "permutation" or "bootstrap"
cor logical: if TRUE computes eigenvalues from a correlation matrix, else from a covariance matrix (eigenComputes)
model character: bootstraps from a principal component analysis ("components") or from a factor analysis ("factors")
... variable: additionnal parameters to give to the cor or cov functions

Value

values data.frame: mean, median, quantile, standard deviation, minimum and maximum of bootstrapped eigenvalues

Author(s)

Gilles Raiche
Centre sur les Applications des Modeles de Reponses aux Items (CAMRI)
Universite du Quebec a Montreal
raiche.gilles@uqam.ca, http://www.er.uqam.ca/nobel/r17165/

References

Buja, A. and Eyuboglu, N. (1992). Remarks on parallel analysis. Multivariate Behavioral Research, 27(4), 509-540.

Zwick, W. R. and Velicer, W. F. (1986). Comparison of five rules for determining the number of components to retain. Psychological bulletin, 99, 432-442.

See Also

principalComponents, iterativePrincipalAxis, rRecovery

Examples

# .......................................................
# Example from the iris data
 eigenvalues <- eigenComputes(x=iris[,-5])
 
# Permutation parallel analysis distribution
 aparallel   <- eigenBootParallel(x=iris[,-5], quantile=0.95)$quantile

# Number of components to retain
 results     <- nScree(x = eigenvalues, aparallel = aparallel)
 results$Components
 plotnScree(results)
# ......................................................

# ......................................................
# Bootstrap distributions stude of the eigenvalues from iris data
# with different correlation methods
 eigenBootParallel(x=iris[,-5],quantile=0.05,
                   option="bootstrap",method="pearson")
 eigenBootParallel(x=iris[,-5],quantile=0.05,
                   option="bootstrap",method="spearman")
 eigenBootParallel(x=iris[,-5],quantile=0.05,
                   option="bootstrap",method="kendall")
 

[Package nFactors version 2.3.1 Index]