Rheolef  7.1
an efficient C++ finite element environment
burgers_diffusion_error.cc

The diffusive Burgers equation – error analysis

#include "rheolef.h"
using namespace rheolef;
using namespace std;
int main(int argc, char**argv) {
environment rheolef (argc, argv);
Float err_expected = (argc > 1) ? atof(argv[1]) : 1;
din >> catchmark("epsilon") >> epsilon;
branch even("t","u");
Float t=0; field uh;
Float err_linf_l2 = 0,
err_l2_l2 = 0,
err_linf_linf = 0,
meas_omega = 0;
size_t n = 0;
bool have_meas_omega = false;
dout << "# t err_l2(t) err_linf(t)" << endl;
while (din >> even(t,uh)) {
const geo& omega = uh.get_geo();
if (!have_meas_omega) {
meas_omega = integrate(omega);
have_meas_omega = true;
}
iopt.set_order (2*uh.get_space().degree()+1);
field pi_h_u = interpolate (uh.get_space(), u_exact(epsilon,t));
Float err_linf = field(uh - pi_h_u).max_abs();
Float err_l2 = sqrt(integrate (omega, sqr(uh - u_exact(epsilon,t)), iopt)/meas_omega);
err_linf_linf = max(err_linf_linf, err_linf);
err_linf_l2 = max(err_linf_l2, err_l2);
err_l2_l2 += sqr(err_l2);
dout << t << " " << err_l2 << " " << err_linf << endl;
++n;
}
err_l2_l2 = sqrt(err_l2_l2/n);
dout << "# err_l2_l2 = " << err_l2_l2 << endl
<< "# err_linf_l2 = " << err_linf_l2 << endl
<< "# err_linf_linf = " << err_linf_linf << endl;
return (err_linf_l2 <= err_expected) ? 0 : 1;
}
rheolef::catchmark
see the catchmark page for the full documentation
Definition: catchmark.h:67
rheolef::integrate_option::set_order
void set_order(size_t r)
Definition: integrate_option.h:254
field
see the field page for the full documentation
rheolef::field
field_basic< Float > field
see the field page for the full documentation
Definition: field.h:419
rheolef::integrate
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
rheolef.h
rheolef - reference manual
rheolef::integrate_option
see the integrate_option page for the full documentation
Definition: integrate_option.h:125
rheolef::interpolate
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::din
idiststream din
see the diststream page for the full documentation
Definition: diststream.h:427
rheolef::environment
see the environment page for the full documentation
Definition: environment.h:115
main
int main(int argc, char **argv)
Definition: burgers_diffusion_error.cc:29
rheolef
This file is part of Rheolef.
Definition: compiler_eigen.h:37
u_exact
g u_exact
Definition: taylor_exact.h:26
Float
see the Float page for the full documentation
u_exact
Definition: interpolate_RTk_polynom.icc:125
branch
see the branch page for the full documentation
burgers_diffusion_exact.h
The diffusive Burgers equation – its exact solution.
mkgeo_ball.n
n
Definition: mkgeo_ball.sh:150
rheolef::dout
odiststream dout(cout)
see the diststream page for the full documentation
Definition: diststream.h:430
epsilon
Float epsilon
Definition: transmission_error.cc:25
rheolef::std
Definition: vec_expr_v2.h:391
geo
see the geo page for the full documentation