GNU R for Estimation of Covariance and Correlation -- corpcor
GNU R package which implements a James-Stein-type shrinkage estimator for the
covariance matrix, with separate shrinkage for variances and correlations. The
approach is both computationally as well as statistically very efficient, it is
applicable to "small n, large p" data, and always returns a positive definite
and well-conditioned covariance matrix. In addition to inferring the
covariance matrix the package also provides shrinkage estimators for partial
correlations and partial variances. The inverse of the covariance and
correlation matrix can be efficiently computed, as well as any arbitrary power
of the shrinkage correlation matrix. Furthermore, functions are available for
fast singular value decomposition, for computing the pseudoinverse, and for
checking the rank and positive definiteness of a matrix.
