The p-Laplacian problem by the fixed-point method.
int main(
int argc,
char**argv) {
Float eps = std::numeric_limits<Float>::epsilon();
string approx = (argc > 2) ? argv[2] : "P1";
Float p = (argc > 3) ? atof(argv[3]) : 1.5;
Float w = (argc > 4) ? (is_float(argv[4]) ? atof(argv[4]) :2/
p) :1;
Float tol = (argc > 5) ? atof(argv[5]) : 1e5*eps;
size_t max_it = (argc > 6) ? atoi(argv[6]) : 500;
derr << "# P-Laplacian problem by fixed-point:" << endl
<< "# geo = " << omega.name() << endl
<< "# approx = " << approx << endl
<< "# w = " << w << endl
<< "# tol = " << tol << endl;
space Xh (omega, approx);
Xh.block ("boundary");
form m = integrate (
u*v);
field uh (Xh), uh_star (Xh, 0.);
uh["boundary"] = uh_star["boundary"] = 0;
derr << "# n r v" << endl;
size_t n = 0;
do {
form a = integrate(compose(
eta(
p),norm2(grad(uh)))*dot(grad(
u),grad(v)));
pm.solve (mrh, rh);
r = rh.max_abs();
if (n == 0) { r0 = r; }
Float v = (n == 0) ? 0 : log10(r0/r)/n;
derr << n << " " << r << " " << v << endl;
if (r <= tol || n++ >= max_it) break;
uh = w*uh_star + (1-w)*uh;
} while (true);
return (r <= tol) ? 0 : 1;
}
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 geo page for the full documentation
see the problem page for the full documentation
see the catchmark page for the full documentation
see the environment page for the full documentation
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 Poisson problem with homogeneous Dirichlet boundary condition – solver function.
void dirichlet(const field &lh, field &uh)
The p-Laplacian problem – the eta function.
This file is part of Rheolef.
rheolef - reference manual