code: def edge_lengths(self):
          
  
          simplex = self.simplices.T
  
          # simplex is vectors a, b, c defining the corners
          a = self.points[simplex[0]]
          b = self.points[simplex[1]]
          c = self.points[simplex[2]]
  
          ## dot products to obtain angles
          ab = np.arccos((a * b).sum(axis=1))
          bc = np.arccos((b * c).sum(axis=1))
          ac = np.arccos((a * c).sum(axis=1))
  
          ## As this is a unit sphere, angle = length so ...
  
          return ab, bc, ac
docs: Compute the edge-lengths of each triangle in the triangulation.