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

The Helmholtz problem with Neumann boundary conditions by the discontinuous Galerkin method

#include "rheolef.h"
using namespace rheolef;
using namespace std;
int main(int argc, char**argv) {
environment rheolef (argc, argv);
geo omega (argv[1]);
space Xh (omega, argv[2]);
size_t d = omega.dimension();
size_t k = Xh.degree();
Float beta = (k+1)*(k+d)/Float(d);
trial u (Xh); test v (Xh);
form a = integrate (u*v + dot(grad_h(u),grad_h(v)))
+ integrate ("internal_sides",
beta*penalty()*jump(u)*jump(v)
- jump(u)*average(dot(grad_h(v),normal()))
- jump(v)*average(dot(grad_h(u),normal())));
field lh = integrate (f(d)*v) + integrate ("boundary", g(d)*v);
field uh(Xh);
problem p (a);
p.solve (lh, uh);
dout << uh;
}
g
u_exact g
Definition: burgers_diffusion_exact.h:33
form
see the form page for the full documentation
rheolef::dot
rheolef::std enable_if ::type dot const Expr1 expr1, const Expr2 expr2 dot(const Expr1 &expr1, const Expr2 &expr2)
dot(x,y): see the expression page for the full documentation
Definition: vec_expr_v2.h:415
field
see the field page for the full documentation
rheolef::normal
details::field_expr_v2_nonlinear_terminal_function< details::normal_pseudo_function< Float > > normal()
normal: see the expression page for the full documentation
Definition: field_expr_terminal.h:439
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
mkgeo_ball.f
f
Definition: mkgeo_ball.sh:221
space
see the space page for the full documentation
sinusprod_helmholtz.h
The sinus product function – right-hand-side and boundary condition for the Helmholtz problem.
rheolef.h
rheolef - reference manual
p
Definition: sphere.icc:25
a
Definition: diffusion_isotropic.h:25
rheolef::environment
see the environment page for the full documentation
Definition: environment.h:115
lh
field lh(Float epsilon, Float t, const test &v)
Definition: burgers_diffusion_operators.icc:25
main
int main(int argc, char **argv)
Definition: neumann_dg.cc:29
rheolef
This file is part of Rheolef.
Definition: compiler_eigen.h:37
test
see the test page for the full documentation
problem
see the problem page for the full documentation
u
Definition: leveque.h:25
Float
see the Float page for the full documentation
mkgeo_ball.d
d
Definition: mkgeo_ball.sh:154
u
Float u(const point &x)
Definition: transmission_error.cc:26
rheolef::penalty
details::field_expr_v2_nonlinear_terminal_function< details::penalty_pseudo_function< Float > > penalty()
penalty(): see the expression page for the full documentation
Definition: field_expr_terminal.h:626
rheolef::grad_h
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_h(const Expr &expr)
grad_h(uh): see the expression page for the full documentation
Definition: field_expr_terminal.h:949
trial
see the test page for the full documentation
rheolef::Float
double Float
see the Float page for the full documentation
Definition: Float.h:143
rheolef::dout
odiststream dout(cout)
see the diststream page for the full documentation
Definition: diststream.h:430
rheolef::std
Definition: vec_expr_v2.h:391
geo
see the geo page for the full documentation
rk::beta
Float beta[][pmax+1]
Definition: runge_kutta_semiimplicit.icc:60