Rheolef  7.2
an efficient C++ finite element environment
 
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p_laplacian_post.cc
Go to the documentation of this file.
1
21#include "rheolef.h"
22using namespace rheolef;
23using namespace std;
24#include "eta.h"
25void usage(string name) {
26 derr << name << ": usage: "
27 << name << " "
28 << "[-|file[.field[.gz]]] "
29 << "[-check] "
30 << "[-residue] "
31 << "[-criteria] "
32 << endl;
33 exit (1);
34}
35field residue (Float p, const field& uh) {
36 const space& Xh = uh.get_space();
37 trial u (Xh); test v (Xh);
38 field lh = integrate (v);
39 form m = integrate (u*v);
40 form a = integrate (compose (eta(p), norm2(grad(uh)))*dot(grad(u),grad(v)));
41 field mrh = a*uh - lh;
42 mrh["boundary"] = 0;
43 field rh (Xh);
44 problem pm (m);
45 pm.solve(mrh, rh);
46 rh["boundary"] = 0;
47 return rh;
48}
49void check (Float p, const field& uh) {
50 field rh = residue(p, uh);
51 const space& Xh = rh.get_space();
52 trial u (Xh); test v (Xh);
53 form m = integrate (u*v);
54 Float res = sqrt(m(rh,rh));
55 derr << "check: residue = " << res << endl;
56 check_macro (res < 1e-3, "unexpected residue");
57}
58field criteria (Float p, const field& uh) {
59 const space& Xh = uh.get_space();
60 if (uh.get_approx() == "P1") return lazy_interpolate (Xh, abs(uh));
61 return lazy_interpolate (Xh, pow(norm(grad(uh)), p/2));
62}
63void
65 in >> catchmark("p") >> p
66 >> catchmark("u") >> uh;
67}
68int main(int argc, char**argv) {
69 environment rheolef (argc,argv);
70 if (argc < 3) usage(argv[0]);
71 Float p;
72 field uh;
73 if (string (argv[1]) == "-") {
74 load (din, p, uh);
75 } else {
76 idiststream in;
77 in.open(argv[1], "field");
78 load (in, p, uh);
79 }
80 for (int i = 2; i < argc; i++) {
81 if (strcmp (argv[i], "-check") == 0) { check (p, uh); }
82 else if (strcmp (argv[i], "-residue") == 0) { dout << catchmark("ru") << residue (p, uh); }
83 else if (strcmp (argv[i], "-criteria") == 0) { dout << catchmark("c") << criteria (p, uh); }
84 else {
85 derr << argv[0] << ": unknown option \'" << argv[i] << "'" << endl;
86 usage(argv[0]);
87 }
88 }
89}
void usage()
Definition csr.cc:261
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 problem page for the full documentation
see the catchmark page for the full documentation
Definition catchmark.h:67
see the environment page for the full documentation
idiststream: see the diststream page for the full documentation
Definition diststream.h:336
void open(std::string filename, std::string suffix="", const communicator &comm=communicator())
This routine opens a physical input file.
Definition diststream.cc:85
see the space page for the full documentation
see the test page for the full documentation
see the test page for the full documentation
The p-Laplacian problem – the eta function.
int main()
Definition field2bb.cc:58
check_macro(expr1.have_homogeneous_space(Xh1), "dual(expr1,expr2); expr1 should have homogeneous space. HINT: use dual(interpolate(Xh, expr1),expr2)")
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
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
T norm2(const vec< T, M > &x)
norm2(x): see the expression page for the full documentation
Definition vec.h:379
space_mult_list< T, M > pow(const space_basic< T, M > &X, size_t n)
Definition space_mult.h:120
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
rheolef::std enable_if ::type dot const Expr1 expr1, const Expr2 expr2 dot(const Expr1 &expr1, const Expr2 &expr2)
T norm(const vec< T, M > &x)
norm(x): see the expression page for the full documentation
Definition vec.h:387
details::field_expr_v2_nonlinear_node_nary< typename details::function_traits< Function >::functor_type, typename details::field_expr_v2_nonlinear_terminal_wrapper_traits< Exprs >::type... > ::type compose(const Function &f, const Exprs &... exprs)
see the compose page for the full documentation
Definition compose.h:247
STL namespace.
field residue(Float p, const field &uh)
field criteria(Float p, const field &uh)
void check(Float p, const field &uh)
void load(idiststream &in, Float &p, field &uh)
rheolef - reference manual
Definition eta.h:25
Definition sphere.icc:25
Definition leveque.h:25