Rheolef  7.2
an efficient C++ finite element environment
neumann-laplace-check.cc
Go to the documentation of this file.
1 #include "rheolef.h"
22 using namespace rheolef;
23 using namespace std;
24 size_t N;
25 Float u_ex (const point& x) { return - 1./12 + (x[0]*(1-x[0]) + x[1]*(1-x[1]) + x[2]*(1-x[2]))/(2.*N); }
26 int main(int argc, char**argv) {
27  environment rheolef (argc, argv);
28  Float error_linf_expected = (argc > 1) ? atof(argv[1]) : 1e+38;
29  field uh; din >> uh;
30  const space& Xh = uh.get_space();
31  N = Xh.get_geo().dimension();
32  field pi_h_u = lazy_interpolate(Xh, u_ex);
33  field eh = pi_h_u - uh;
34  trial u (Xh); test v (Xh);
35  form m = integrate (u*v);
36  form a = integrate (dot(grad(u),grad(v)));
37  derr << "error_l2 " << sqrt(m(eh,eh)) << endl
38  << "error_h1 " << sqrt(fabs(a(eh,eh))) << endl
39  << "error_linf " << eh.max_abs() << endl;
40  return (eh.max_abs() <= error_linf_expected) ? 0 : 1;
41 }
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 point page for the full documentation
see the environment page for the full documentation
Definition: environment.h:121
idiststream din(cin)
see the diststream page for the full documentation
Definition: diststream.h:464
odiststream derr(cerr)
see the diststream page for the full documentation
Definition: diststream.h:473
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)
This file is part of Rheolef.
std::enable_if< details::has_field_rdof_interface< 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
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::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
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
int main(int argc, char **argv)
size_t N
Float u_ex(const point &x)
rheolef - reference manual
Definition: leveque.h:25