Rheolef  7.2
an efficient C++ finite element environment
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}
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
Definition: environment.h:121
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
point u(const point &x)
The p-Laplacian problem – the eta function.
check_macro(expr1.have_homogeneous_space(Xh1), "dual(expr1,expr2); expr1 should have homogeneous space. HINT: use dual(interpolate(Xh, expr1),expr2)")
class rheolef::details::field_expr_v2_nonlinear_node_unary compose
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
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
T norm(const vec< T, M > &x)
norm(x): see the expression page for the full documentation
Definition: vec.h:387
STL namespace.
field residue(Float p, const field &uh)
int main(int argc, char **argv)
field criteria(Float p, const field &uh)
void check(Float p, const field &uh)
void usage(string name)
void load(idiststream &in, Float &p, field &uh)
rheolef - reference manual
Definition: eta.h:25
Definition: sphere.icc:25
Definition: leveque.h:25