A simple R function to compute estimates of effective dimensionality (ED), either from raw data or from a correlation/covariance matrix. The function returns four estimators, both uncorrected and corrected for small-sample bias if enough information is available. Disattenuated estimates can also be computed if desired, by supplying a vector of reliability coefficients.
See: Del Giudice, M. (2020). Effective dimensionality: A tutorial. Multivariate Behavioral Research.