The Matrix Means Toolbox includes the following files:|
alm.m - Computes the Ando-Li-Mathias mean of k matrices 
cheap.m - Computes the cheap mean of k matrices 
dist.m - Computes the Riemannian and Euclidean distance between A and B
explog.m - Computes the explog mean of k matrices 
karcher.m - Computes the Karcher mean of k matrices using a Richardson-like iteration 
mean2.m - Computes the geometric mean of two matrices with three algorithms 
nbmp.m - Computes the Nakamura/Bini-Meini-Poloni mean of k matrices [5,7]
random.m - Generates k random positive definite matrices
sharp.m - Computes $A\#_t B$
 T. Ando, C.-K. Li and R. Mathias, Geometric means, Linear Algebra Appl., 385-1 (2004) pp. 305-334.
 V. Arsigny, P. Fillard, X. Pennec and N. Ayache, Geometric means in a novel vector space structure on symmetric positive-definite matrices, SIAM J. Matrix Anal. Appl., 29-1 (2006/07), pp. 328-347.
 D. A. Bini and B. Iannazzo, A note on computing matrix geometric means, Advances Comp. Math., 35-2/4 (2010), pp. 175-192.
 D. A. Bini and B. Iannazzo, Computing the Karcher mean of symmetric positive definite matrices, to appear in Linear Algebra Appl., 2012.
 D. A. Bini, B. Meini and F. Poloni, An effective matrix geometric mean satisfying the Ando-Li-Mathias properties, Math. Comp., 79 (2010), pp. 437-452.
 B. Iannazzo, The geometric mean of two matrices from a computational viewpoint, arXiv preprint arXiv:1201.0101, 2011.
 K. Nakamura, Geometric Means of Positive Operators, Kyungpook Math. J. 49 (2009), 167-181
mmtoolbox 2.2 - Febraury 13, 2014 - Fixed a bug, removed unused files, fixed
indent, optimized the Richardson iteration.
mmtoolbox 2.1 - February 11, 2014 - removed unused cycle and duplicated
Cholesky factorization in mean2.m. In karcher.m changed log1 with log1p.
mmtoolbox 2.0 - January 10, 2014 - rewritten all files again with major adjustments. Included full Matlab and cell-array support.
Removed gradient.m and rich.m for the Karcher mean; now there is the file karcher.m which computes the Karcher mean using the Richardson iteration, starting from the arithmetic mean
and with the exponential at the end. Changed geomean.m to mean2.m. Many bugs have been removed.
mmtoolbox 1.1b2 - November 26, 2011 - Some minor adjustments to the formatting
of the files.
mmtoolbox 1.1b1 - August, 19, 2011 - rewritten all files from scratch with a uniform style, help in line,
and more; changed the square root computation to the Cholesky factor whenever possible;
changed the name of the file manton.m to gradient.m; changed the name of the file bmp.m to nbmp.m, as
soon as the reference  was individuated; fixed a bug in dist.m.
mmtoolbox 1.0 - July 11, 2010 - first release