text: # -*- coding: utf-8 -*-
  #
  from __future__ import division
  
  import sympy
  
  from .helpers import fs_r00, fs_rr0, z
  from ..helpers import untangle
  
  
  class AlbrechtCollatz(object):
      """
      J. Albrecht, L. Collatz,
      Zur numerischen Auswertung mehrdimensionaler Integrale,
      ZAMM, Volume 38, Issue 1-2, 1958, Pages 1–15,
      <https://doi.org/10.1002/zamm.19580380102>
      """
  
      def __init__(self, symbolic=False):
          frac = sympy.Rational if symbolic else lambda x, y: x / y
  
          self.degree = 3
          data = [(frac(1, 4), z()), (frac(1, 12), fs_r00(1)), (frac(1, 48), fs_rr0(1))]
  
          self.points, self.weights = untangle(data)
          self.weights *= 8
          return
  