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

The combustion problem – error analysis

#include "rheolef.h"
using namespace rheolef;
using namespace std;
int main(int argc, char**argv) {
environment rheolef (argc,argv);
bool is_upper = (argc > 1) && (argv[1][0] == '1');
bool is_crit = (argc > 1) && (argv[1][0] == 'c');
Float tol = (argc > 2) ? atof(argv[2]) : 1e-15;
Float lambda_h;
field uh;
din >> catchmark("lambda") >> lambda_h
>> catchmark("u") >> uh;
Float lambda = (is_crit ? lambda_c() : lambda_h);
const geo& omega = uh.get_geo();
const space& Xh = uh.get_space();
field pi_h_u = interpolate (Xh, u_exact(lambda,is_upper));
field eh = pi_h_u - uh;
integrate_option iopt;
iopt.set_family(integrate_option::gauss);
iopt.set_order(2*Xh.degree()+1);
Float err_l2
= sqrt(integrate(omega, norm2(uh - u_exact(lambda,is_upper)), iopt));
Float err_h1
= sqrt(integrate(omega, norm2(grad(uh)-grad_u(lambda,is_upper)), iopt));
Float err_linf = eh.max_abs();
dout << "err_linf = " << err_linf << endl
<< "err_l2 = " << err_l2 << endl
<< "err_h1 = " << err_h1 << endl;
return (err_h1 < tol) ? 0 : 1;
}
see the Float page for the full documentation
see the field page for the full documentation
see the geo page for the full documentation
T max_abs() const
Definition: field.h:731
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
see the space page for the full documentation
int main(int argc, char **argv)
The combustion problem – its exact solution.
field_basic< T, M > eh
Float lambda_c()
Definition: lambda_c.h:44
This file is part of Rheolef.
std::enable_if< details::is_field_convertible< Expr >::value,details::field_expr_v2_nonlinear_terminal_field< typename Expr::scalar_type,typename Expr::memory_type,details::differentiate_option::gradient >>::type grad(const Expr &expr)
grad(uh): see the expression page for the full documentation
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
T norm2(const vec< T, M > &x)
norm2(x): see the expression page for the full documentation
Definition: vec.h:379
rheolef - reference manual
g u_exact
Definition: taylor_exact.h:26
tensor grad_u