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["Andy S." <>]

Hello.

I need to solve some quadratic programs  by specifying the problem through iterators. At the bottom there is  a dummy example which runs fine (problem is infeasible). The problem is when I change the constraints to be all ">=":

std::array<CGAL::Comparison_result, numAConstraints> relationships 

              = { CGAL::LARGER,CGAL::LARGER,CGAL::LARGER,CGAL::LARGER, };

Then I get: "basis-inverse check: failed (row=0 | col=1)" from qp_solver_imp.h line 1155.

Thank you,

Anderson

This is the sample code that runs without crashing, all constraints are "<=":

int test(){

    const int numAConstraints = 4;

    const int numVariables = 3;

    typedef CGAL::Quadratic_program_from_iterators

    <double**,  // for A

     double*, // for b

    std::array<CGAL::Comparison_result, numAConstraints>::const_iterator, // for r

    bool*,    // for fl

    double*,   // for l

    bool*,    // for fu

    double*,   // for u

    double**,  // for D

    double*>  // for c 

    Program;

typedef CGAL::Quadratic_program_solution<ET> Solution;

    double  Ax[] = { 1, -1, -1, 1 };      // column for x

    double  Ay[] = { -2, -2, 2, -1 };  

    double  Az[] = { 1, 0.0, -5, 5 };   

    double*  A[] = { Ax, Ay, Az };        // A comes columnwise

    double   b[] = { -2.4, -6, -2, 1.0 };  // right-hand side

    std::array<CGAL::Comparison_result, numAConstraints> relationships 

              = { CGAL::SMALLER,CGAL::SMALLER,CGAL::SMALLER, CGAL::SMALLER }; 

    bool fl[] = { true, true, true };    // both x, y are lower-bounded

    double   l[] = { 0, 0, 0 };

    bool fu[] = { false, false, false };    // only y is upper-bounded

    double   u[] = { 0, 0, 0 };            // x's u-entry is ignored

    double  D1[] = { 1 };                // 2D_{1,1}

    double  D2[] = { 0, 0.1 }; 

    double  D3[] = { 10, 0.0, 100.0 };   

    double*  D[] = { D1, D2, D3 };        // D-entries on/below diagonal ROWISE

    double   c[] = { -200, -5, -25 };

    double  c0 = 64;                

    Program qp(numVariables, numAConstraints, A, b, relationships.begin(), fl, l, fu, u, D, c, c0);

    // solve the program, using ET as the exact type

    Solution s = CGAL::solve_quadratic_program(qp, ET());

    std::cout << s;

    return 0;

}