Just want to share updated link for the Geometric Median reference website as it is useful for understanding how to use the function and the epsilon input parameter. (Original link was in .cpp file that is now an obsolete address)
[https://bebac.at/articles/A-Rant-About-Nice-Numbers.phtml]
PDF of the website as-is today since... why not. Geometric Median is fantastic.
GeometricMedian-Primer-Rant_About_Nice_Numbers-bebeac.pdf