mirror of https://github.com/CGAL/cgal
47 lines
1.5 KiB
C++
47 lines
1.5 KiB
C++
// example: output basic constraint indices
|
|
// the QP below is the first quadratic program example in the user manual
|
|
#include <iostream>
|
|
|
|
#include <CGAL/QP_models.h>
|
|
#include <CGAL/QP_functions.h>
|
|
|
|
// choose exact integral type
|
|
#ifdef CGAL_USE_GMP
|
|
#include <CGAL/Gmpz.h>
|
|
typedef CGAL::Gmpz ET;
|
|
#else
|
|
#include <CGAL/MP_Float.h>
|
|
typedef CGAL::MP_Float ET;
|
|
#endif
|
|
|
|
// program and solution types
|
|
typedef CGAL::Quadratic_program<int> Program;
|
|
typedef CGAL::Quadratic_program_solution<ET> Solution;
|
|
|
|
int main() {
|
|
// by default, we have a nonnegative QP with Ax <= b
|
|
Program qp (CGAL::SMALLER, true, 0, false, 0);
|
|
|
|
// now set the non-default entries: 0 <-> x, 1 <-> y
|
|
qp.set_a(0, 0, 1); qp.set_a(1, 0, 1); qp.set_b(0, 7); // x + y <= 7
|
|
qp.set_a(0, 1, -1); qp.set_a(1, 1, 2); qp.set_b(1, 4); // -x + 2y <= 4
|
|
qp.set_u(1, true, 4); // y <= 4
|
|
qp.set_d(0, 0, 2); qp.set_d (1, 1, 8); // x^2 + 4 y^2
|
|
qp.set_c(1, -32); // -32y
|
|
qp.set_c0(64); // +64
|
|
|
|
// solve the program, using ET as the exact type
|
|
Solution s = CGAL::solve_quadratic_program(qp, ET());
|
|
|
|
// print basic constraint indices (we know that there is only one: 1)
|
|
if (s.is_optimal()) { // we know that, don't we?
|
|
std::cout << "Basic constraints: ";
|
|
for (Solution::Index_iterator it = s.basic_constraint_indices_begin();
|
|
it != s.basic_constraint_indices_end(); ++it)
|
|
std::cout << *it << " ";
|
|
std::cout << std::endl;
|
|
}
|
|
|
|
return 0;
|
|
}
|