Rheolef  7.2
an efficient C++ finite element environment
neumann-laplace.cc

The Poisson problem with Neumann boundary conditions.

The Poisson problem with Neumann boundary conditions

#include "rheolef.h"
using namespace rheolef;
using namespace std;
size_t d;
Float f (const point& x) { return 1; }
Float g (const point& x) { return -0.5/d; }
int main(int argc, char**argv) {
environment rheolef (argc, argv);
geo omega (argv[1]);
d = omega.dimension();
space Xh (omega, argv[2]);
trial u (Xh); test v (Xh);
field lh = integrate (f*v) + integrate ("boundary", g*v);
form A = {{ a, b},
{ trans(b), 0}};
field Bh = { lh, 0};
field Uh (Bh.get_space(), 0);
A.set_symmetry(true);
problem p (A);
p.solve (Bh, Uh);
dout << Uh[0];
}
field lh(Float epsilon, Float t, const test &v)
see the Float page for the full documentation
see the field page for the full documentation
see the form page for the full documentation
see the geo page for the full documentation
see the point page for the full documentation
see the problem page for the full documentation
see the environment page for the full documentation
Definition: environment.h:121
see the space page for the full documentation
see the test page for the full documentation
see the test page for the full documentation
point u(const point &x)
rheolef::details::is_vec dot
This file is part of Rheolef.
std::enable_if< details::has_field_rdof_interface< Expr >::value, details::field_expr_v2_nonlinear_terminal_field< typenameExpr::scalar_type, typenameExpr::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:211
csr< T, sequential > trans(const csr< T, sequential > &a)
trans(a): see the form page for the full documentation
Definition: csr.h:455
STL namespace.
size_t d
int main(int argc, char **argv)
Float f(const point &x)
Float g(const point &x)
rheolef - reference manual
Definition: cavity_dg.h:29
Definition: cavity_dg.h:25
Definition: sphere.icc:25
Definition: leveque.h:25