centering               Centering method This method implements the
                        double centering and U-centering during
                        computing distance covariance.
dcor.test               Permutation test of distance correlation and
                        partial distance correlation
dcor.ttest              Distance correlation T-test It uses the result
                        of U-statistic distance correlation to test
                        independence for high dimensional data
dcov                    Distance covariance
dcov2d                  Fast distance covariance for two bivariate
                        variables
mdcov                   Marginal distance covariance This function
                        implements the method of calculating distance
                        covariance between y and each column in x
pcov                    Projection covariance between two random
                        vectors This function implements the projection
                        correlation in 'Zhu et al.(2017)'
pdcov                   Partial distance covariance
