docs: def get_orientation(k, i, j):
          from pylocus.basics_angles import from_0_to_2pi
          """calculate angles theta_ik and theta_jk theta produce point Pk.
          Should give the same as get_absolute_angle! """
          theta_ij = own.abs_angles[i, j]
          theta_ji = own.abs_angles[j, i]
  
          # complicated
          xi = own.points[i, 0]
          xj = own.points[j, 0]
          yi = own.points[i, 1]
          yj = own.points[j, 1]
          w = np.array([yi - yj, xj - xi])
          test = np.dot(own.points[k, :] - own.points[i, :], w) > 0
  
          # more elegant
          theta_ik = truth.abs_angles[i, k]
          diff = from_0_to_2pi(theta_ik - theta_ij)
          test2 = (diff > 0 and diff < pi)
          assert (test == test2), "diff: %r, scalar prodcut: %r" % (diff, np.dot(
              own.points[k, :] - own.points[i, :], w))
  
          thetai_jk = truth.get_theta(i, j, k)
          thetaj_ik = truth.get_theta(j, i, k)
          if test:
              theta_ik = theta_ij + thetai_jk
              theta_jk = theta_ji - thetaj_ik
          else:
              theta_ik = theta_ij - thetai_jk
              theta_jk = theta_ji + thetaj_ik
          theta_ik = from_0_to_2pi(theta_ik)
          theta_jk = from_0_to_2pi(theta_jk)
          return theta_ik, theta_jk