14 July 2023 09:41:36 PM

quadrilateral_witherden_rule_test():
  C version
  Test quadrilateral_witherden_rule().

quadrilateral_witherden_rule_test01():
  Quadrature rule for the unit quadrilateral.
  Precision p = 5

  Number of nodes N = 8

     I      W          X           Y

     0    0.204082    0.841565         0.5
     1    0.204082         0.5    0.841565
     2    0.204082    0.158435         0.5
     3    0.204082         0.5    0.158435
     4   0.0459184    0.940959    0.940959
     5   0.0459184    0.940959   0.0590414
     6   0.0459184   0.0590414    0.940959
     7   0.0459184   0.0590414   0.0590414

  Weight Sum = 1

quadrilateral_witherden_rule_test02():
  Test the precision of a quadrature rule for the unit quadrilateral.

  Number of nodes N = 8

  Stated precision of rule    = 5
  Number of quadrature points = 8

  Degree  Maximum error

   0               1.11022e-16
   1               1.11022e-16
   2               5.55112e-17
   3               2.77556e-17
   4               2.77556e-17
   5               2.77556e-17
   6               0.000308642
   7               0.000817901

quadrilateral_witherden_rule_test03():
  Test the precision of quadrature rules for the unit quadrilateral.
  Check rules of precision p = 0 through 21
  for error in approximating integrals of monomials.

              maximum                   maximum
   p          absolute                  relative
              error                     error

   0                         0                         0
   1                         0                         0
   2               5.55112e-17               1.66533e-16
   3               5.55112e-17               1.66533e-16
   4               1.11022e-16               2.22045e-16
   5               1.11022e-16               2.22045e-16
   6               5.55112e-17               2.08167e-16
   7               5.55112e-17               2.08167e-16
   8               2.22045e-16               8.67362e-16
   9               2.22045e-16               1.04083e-15
  10               4.44089e-16                1.1241e-15
  11               4.44089e-16                 1.249e-15
  12               6.66134e-16                1.9984e-15
  13               6.66134e-16                1.9984e-15
  14               2.77556e-16               1.33227e-15
  15               2.77556e-16               1.33227e-15
  16               6.66134e-16               1.36002e-15
  17               6.66134e-16               1.36002e-15
  18               6.66134e-16                5.4956e-15
  19               6.66134e-16               5.53377e-15
  20               1.11022e-15               2.81025e-15
  21               1.11022e-15               2.81025e-15

quadrilateral_witherden_rule_test()
  Normal end of execution.

14 July 2023 09:41:36 PM