ZHANG, Ruda July 20, 2021:  More on matrix manifolds, Riemannian center of mass, matrix exponential. [cfb964f]
ZHANG, Ruda March 09, 2021:  Defind mode, median; more on Gaussian rv, probabilistic models on matrix manifolds. [7c5a23c]
ZHANG, Ruda March 07, 2021:  More on probabilistic models on matrix manifolds. [97edf7f]
ZHANG, Ruda March 07, 2021:  Add statistics on manifold. [246fcda]