Hi, everyone!
I am solving a planar problem using quad elements and the number of quadrature points bothers me a little. A minimal [interactive] working example would be like this:
In [1]: from sfepy.discrete import Integral In [2]: i = Integral('i', 1) In [3]: i.get_qp('2_4') Out[3]: (array([[0.90824829, 0.5 ], [0.29587585, 0.85355339], [0.29587585, 0.14644661]]), array([0.33333333, 0.33333333, 0.33333333]))
In [4]: i = Integral('i', 2) In [5]: i.get_qp('2_4') Out[5]: (array([[0.84156503, 0.5 ], [0.15843497, 0.5 ], [0.5 , 0.84156503], [0.5 , 0.15843497], [0.94095855, 0.94095855], [0.94095855, 0.05904145], [0.05904145, 0.94095855], [0.05904145, 0.05904145]]), array([0.20408163, 0.20408163, 0.20408163, 0.20408163, 0.04591837, 0.04591837, 0.04591837, 0.04591837]))
In [6]: i = Integral('i', 3) In [7]: i.get_qp('2_4') Out[7]: (array([[0.21132487, 0.21132487], [0.78867513, 0.21132487], [0.21132487, 0.78867513], [0.78867513, 0.78867513]]), array([0.25, 0.25, 0.25, 0.25]))
Why do I get 8 QPs for order 2 and 4 QPs for order 3? How does the order of the integral relate to the keys in quadrature_tables [1]?
Best regards, Jan
[1] http://sfepy.org/doc-devel/_modules/sfepy/discrete/quadratures.html