Running the code from the replication materials with version 1.0.0 of the "intRinsic" package leads to an error in the function twonn(). The issue was caused internally by the function compute_mus(), which returned an object of the wrong class when a distance matrix was passed as an argument. The problem has been fixed in version 1.0.1 of the package (available from both CRAN and GitHub) with which the replication materials can be run successfully.