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burgers_diffusion_error.cc

The diffusive Burgers equation – error analysis.

The diffusive Burgers equation – error analysis

#include "rheolef.h"
using namespace rheolef;
using namespace std;
#include "burgers_diffusion_exact.h"
int main(int argc, char**argv) {
environment rheolef (argc, argv);
Float err_expected = (argc > 1) ? atof(argv[1]) : 1;
Float epsilon;
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;
}
integrate_option iopt;
iopt.set_order (2*uh.get_space().degree()+1);
field pi_h_u = lazy_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;
}
burgers_diffusion_exact.h
The diffusive Burgers equation – its exact solution.
Float
see the Float page for the full documentation
branch
see the branch page for the full documentation
field
see the field page for the full documentation
geo
see the geo page for the full documentation
rheolef::catchmark
see the catchmark page for the full documentation
Definition catchmark.h:67
rheolef::environment
see the environment page for the full documentation
Definition environment.h:121
rheolef::integrate_option
see the integrate_option page for the full documentation
Definition integrate_option.h:125
rheolef::integrate_option::set_order
void set_order(size_t r)
Definition integrate_option.h:254
main
int main()
Definition field2bb.cc:58
rheolef
This file is part of Rheolef.
Definition compiler_eigen.h:39
rheolef::lazy_interpolate
field_basic< T, M > lazy_interpolate(const space_basic< T, M > &X2h, const field_basic< T, M > &u1h)
see the interpolate page for the full documentation
Definition field.h:871
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:211
std
STL namespace.
rheolef.h
rheolef - reference manual
u_exact
Definition interpolate_RTk_polynom.icc:125
u_exact
g u_exact
Definition taylor_exact.h:26
epsilon
Float epsilon
Definition transmission_error.cc:25