An R Interface to the 'ROPTLIB' Library for Riemannian Manifold Optimization

An R interface to version 0.3 of the 'ROPTLIB' optimization library (see < https://www.math.fsu.edu/~whuang2/> for more information). Optimize real-valued functions over manifolds such as Stiefel, Grassmann, and symmetric positive definite matrices. For details see Martin et al. (2020) . Note that the optional 'ldr' package used in some of this package's examples can be obtained from either the article or from the 'ldr' package < https://cran.r-project.org/package=ldr>.