Bartlett's (1951) test of sphericity tests whether a matrix (of correlations)
is significantly different from an identity matrix. The test provides
probability that the correlation matrix has significant correlations among at
least some of the variables in a dataset, a prerequisite for factor analysis
to work. In other words, before starting with factor analysis, one needs to
check whether Bartlett<U+2019>s test of sphericity is significant.
Usage
check_sphericity(x, ...)
Arguments
x
A dataframe.
...
Arguments passed to or from other methods.
Value
A list of indices related to sphericity.
Details
This function is strongly inspired by the cortest.bartlett
function in the psych package (Revelle, 2016). All credit goes to its
author.
References
Revelle, W. (2016). How To: Use the psych package for Factor Analysis
and data reduction.
Bartlett, M. S. (1951). The effect of standardization on a Chi-square
approximation in factor analysis. Biometrika, 38(3/4), 337-344.