definition

The geometric median of a discrete set of sample points in a Euclidean space is the point minimizing the sum of distances to the sample points. This generalizes the median, which has the property of minimizing the sum of distances for one-dimensional data, and provides a central tendency in higher dimensions. It is also known as the 1-median,[1] spatial median,[2] Euclidean minisum point,[2] or Torricelli point.

calculate

Ref:

1. Wiki of GM

2. Code