Compute the edge-lengths of each triangle in the triangulation.

def edge_lengths(self):
        """
        Compute the edge-lengths of each triangle in the triangulation.
        """
        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]]

        # norm to calculate length
        ab = np.linalg.norm(b - a, axis=1)
        bc = np.linalg.norm(c - a, axis=1)
        ac = np.linalg.norm(a - c, axis=1)

        return ab, bc, ac