Rheolef  7.1
an efficient C++ finite element environment
burgers_diffusion_error.cc
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1 #include "rheolef.h"
26 using namespace rheolef;
27 using namespace std;
29 int main(int argc, char**argv) {
30  environment rheolef (argc, argv);
31  Float err_expected = (argc > 1) ? atof(argv[1]) : 1;
32  Float epsilon;
33  din >> catchmark("epsilon") >> epsilon;
34  branch even("t","u");
35  Float t=0; field uh;
36  Float err_linf_l2 = 0,
37  err_l2_l2 = 0,
38  err_linf_linf = 0,
39  meas_omega = 0;
40  size_t n = 0;
41  bool have_meas_omega = false;
42  dout << "# t err_l2(t) err_linf(t)" << endl;
43  while (din >> even(t,uh)) {
44  const geo& omega = uh.get_geo();
45  if (!have_meas_omega) {
46  meas_omega = integrate(omega);
47  have_meas_omega = true;
48  }
49  integrate_option iopt;
50  iopt.set_order (2*uh.get_space().degree()+1);
51  field pi_h_u = interpolate (uh.get_space(), u_exact(epsilon,t));
52  Float err_linf = field(uh - pi_h_u).max_abs();
53  Float err_l2 = sqrt(integrate (omega, sqr(uh - u_exact(epsilon,t)), iopt)/meas_omega);
54  err_linf_linf = max(err_linf_linf, err_linf);
55  err_linf_l2 = max(err_linf_l2, err_l2);
56  err_l2_l2 += sqr(err_l2);
57  dout << t << " " << err_l2 << " " << err_linf << endl;
58  ++n;
59  }
60  err_l2_l2 = sqrt(err_l2_l2/n);
61  dout << "# err_l2_l2 = " << err_l2_l2 << endl
62  << "# err_linf_l2 = " << err_linf_l2 << endl
63  << "# err_linf_linf = " << err_linf_linf << endl;
64  return (err_linf_l2 <= err_expected) ? 0 : 1;
65 }
int main(int argc, char **argv)
The diffusive Burgers equation – its exact solution.
see the Float page for the full documentation
see the branch page for the full documentation
see the field page for the full documentation
see the geo page for the full documentation
see the catchmark page for the full documentation
Definition: catchmark.h:67
see the environment page for the full documentation
Definition: environment.h:104
see the integrate_option page for the full documentation
idiststream din
see the diststream page for the full documentation
Definition: diststream.h:427
odiststream dout(cout)
see the diststream page for the full documentation
Definition: diststream.h:430
field_basic< Float > field
see the field page for the full documentation
Definition: field.h:419
This file is part of Rheolef.
std::enable_if< details::is_field_expr_v2_nonlinear_arg< Expr >::value &&! is_undeterminated< Result >::value, Result >::type integrate(const geo_basic< T, M > &omega, const Expr &expr, const integrate_option &iopt, Result dummy=Result())
see the integrate page for the full documentation
Definition: integrate.h:202
field_basic< T, M > interpolate(const space_basic< T, M > &V2h, const field_basic< T, M > &u1h)
see the interpolate page for the full documentation
Definition: interpolate.cc:233
rheolef - reference manual
g u_exact
Definition: taylor_exact.h:26
Float epsilon