This commit is contained in:
2020-06-26 20:19:29 +02:00
parent 333cd04e58
commit 0c6d5e130e
8 changed files with 499 additions and 0 deletions
@@ -0,0 +1,98 @@
#include <iostream>
#include <vector>
#include "hdnum.hh"
template<class N>
class EllipseProblem
{
public:
// Exportiere Größentyp
typedef std::size_t size_type;
// Exportiere Zahlentyp
typedef N number_type;
// Dimension der untenstehenden Funktion
std::size_t size () const
{
return 2;
}
// Funktionsauswertung
void F (const hdnum::Vector<N>& x, hdnum::Vector<N>& result) const
{
result[0] = pow(x[0], 2) + pow(x[1], 2) - 4;
result[1] = pow(x[0], 2)/9 + pow(x[1], 2) - 1;
}
// Jacobimatrix
void F_x (const hdnum::Vector<N>& x, hdnum::DenseMatrix<N>& result) const
{
result[0][0] = 2*x[0]; result[0][1] = 2*x[1];
result[1][0] = 2*x[0]/9; result[1][1] = 2*x[1];
}
};
int main ()
{
typedef double Number; // Zahlentyp
typedef EllipseProblem<Number> Problem;
Problem problem;
hdnum::Vector<Number> u(problem.size()); // Vektor für Startpunkt bzw Lösung
hdnum::Vector<Number> result(problem.size()); // Vektor für Funktionswerte
// Newton
hdnum::Newton newton;
newton.set_maxit(20);
newton.set_verbosity(2);
newton.set_reduction(1e-10);
newton.set_abslimit(1e-20);
newton.set_linesearchsteps(3);
// 1. Quadrant
u[0] = 2.0; u[1] = 1.0;
newton.solve(problem,u);
std::cout << "Nullstelle im 1. Quadrant: " << std::setprecision(15) << u << std::endl;
problem.F(u, result);
std::cout << "Funktionswert: " << std::setprecision(15) << result << std::endl;
// 2. Quadrant
u[0] = -2.0; u[1] = 1.0;
newton.solve(problem,u);
std::cout << "Nullstelle im 2. Quadrant: " << std::setprecision(15) << u << std::endl;
problem.F(u, result);
std::cout << "Funktionswert: " << std::setprecision(15) << result << std::endl;
// 3. Quadrant
u[0] = -2.0; u[1] = -1.0;
newton.solve(problem,u);
std::cout << "Nullstelle im 3. Quadrant: " << std::setprecision(15) << u << std::endl;
problem.F(u, result);
std::cout << "Funktionswert: " << std::setprecision(15) << result << std::endl;
// 4. Quadrant
u[0] = 2.0; u[1] = -1.0;
newton.solve(problem,u);
std::cout << "Nullstelle im 4. Quadrant: " << std::setprecision(15) << u << std::endl;
problem.F(u, result);
std::cout << "Funktionswert: " << std::setprecision(15) << result << std::endl;
// Relaxation
hdnum::Banach banach;
banach.set_maxit(5000); // set parameters
banach.set_verbosity(2);
banach.set_reduction(1e-15);
banach.set_abslimit(1e-20);
banach.set_sigma(0.375);
u[0] = 2.0; u[1] = 1.0; // Startwert
banach.solve(problem,u);
std::cout << "Ergebnis: " << std::setprecision(15) << u << std::endl;
return 0;
}