The RcppEnsmallen package brings to R a Header-Only C++ Mathematical Optimization Library for Armadillo. In particular, Ensmallen is a templated C++ mathematical optimization library (by the MLPACK team) that provides a simple set of abstractions for writing an objective function to optimize. After a three month hiatus, the Ensmallen Development Team released a new patch that enabled callbacks for early stopping procedures to receive a lambda function. Outside of that, the group worked on improving automation on new update …