cgal/QP_solver/include/CGAL/QP_solver/QP_functions_impl.h

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// Copyright (c) 1997-2007 ETH Zurich (Switzerland).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// You can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
//
// Author(s) : Bernd Gaertner <gaertner@inf.ethz.ch>
#ifndef CGAL_QP_FUNCTIONS_IMPL_H
#define CGAL_QP_FUNCTIONS_IMPL_H
#include <iostream>
#include <fstream>
#include <CGAL/iterator.h>
#include <CGAL/QP_solver/QP_solver.h>
#include <CGAL/QP_models.h>
#include <CGAL/QP_solution.h>
namespace CGAL {
namespace QP_functions_detail {
// test whether the system is of the form A x == b (equations only)
template <typename R>
bool is_in_equational_form (const R& r)
{
typename R::R_iterator it = r.get_r();
typename R::R_iterator end = it + r.get_m();
for (; it < end; ++it)
if (*it != CGAL::EQUAL) return false;
return true;
}
// test whether the row vectors of A that correpsond to equations
// are linearly independent; this is done using type ET. The value
// type of LinearInequalitySystem must be convertible to ET
template <class Ar, class ET>
bool has_linearly_independent_equations
(const Ar& ar, const ET& /*dummy*/) {
// we solve the following auxiliary LP, using exact type ET:
// --------
// min 0
// A x r 0
// x >= 0
// --------
// Then A has linearly independent equations if and only if all
// artificials have left the basis after phase I; the QP_solver
// diagnostics tells us this
//
// auxiliary LP type
typedef typename
std::iterator_traits<typename Ar::C_iterator>::value_type C_value;
typedef typename
std::iterator_traits<typename Ar::B_iterator>::value_type B_value;
typedef Const_oneset_iterator <C_value> C_iterator;
typedef Const_oneset_iterator <B_value> B_iterator;
typedef Nonnegative_linear_program_from_iterators
<typename Ar::A_iterator, B_iterator,
typename Ar::R_iterator, C_iterator> LP;
// auxiliary LP
LP lp (ar.get_n(), ar.get_m(), ar.get_a(), B_iterator(0), ar.get_r(), C_iterator(0));
// solver Tags
typedef QP_solver_impl::QP_tags<
Tag_true, // Is_linear
Tag_true> // Is_nonnegative
Tags;
// solver type
typedef QP_solver<LP, ET, Tags> Solver;
// now solve auxiliary LP and compute predicate value
Solver solver (lp);
return !solver.diagnostics.redundant_equations;
}
// helper for MPS output: BOUNDS
template <typename P>
void print_bounds
(std::ostream& , const P& ,
CGAL::Tag_true /*is_nonnegative*/)
{
// nop (default bounds are nonnegative)
}
// helper for MPS output: BOUNDS
template <typename P>
void print_bounds
(std::ostream& out, const P& p,
CGAL::Tag_false /*is_nonnegative*/)
{
typename P::FL_iterator fl = p.get_fl();
typename P::FU_iterator fu = p.get_fu();
typename P::L_iterator l = p.get_l();
typename P::U_iterator u = p.get_u();
int n = p.get_n();
out << "BOUNDS\n";
for (int j=0; j<n; ++j, ++fl, ++l, ++fu, ++u) {
if (!*fl || !CGAL::is_zero(*l)) {
if (*fl)
out << " LO BND x" << j << " " << *l << "\n";
else
out << " MI BND x" << j << "\n";
}
if (*fu)
out << " UP BND x" << j << " " << *u << "\n";
}
}
// helper for MPS output: DMATRIX/QMATRIX
template <typename P>
void print_qmatrix
(std::ostream& , const P& ,
CGAL::Tag_true /*is_linear*/)
{
// nop
}
// helper for MPS output: DMATRIX/QMATRIX
template <typename P>
void print_qmatrix
(std::ostream& out, const P& p,
CGAL::Tag_false /*is_linear*/)
{
typename P::D_iterator it = p.get_d();
int n = p.get_n();
bool empty_D = true;
for (int i=0; i<n; ++i, ++it) {
// handle only entries on/below diagonal
for (int j=0; j<i+1; ++j)
if (!CGAL::is_zero(*(*it + j))) {
if (empty_D) {
// first time we see a nonzero entry
out << "QMATRIX\n";
empty_D = false;
}
out << " x" << i << " x" << j << " " << *(*it + j) << "\n";
// QMATRIX format prescribes symmetric matrix
if (i != j)
out << " x" << j << " x" << i << " " << *(*it + j) << "\n";
}
}
}
// check whether the two qp's have the same data; this is the case iff
// they agree in n, m, a, b, r, fl, l, fu, u, d, c, c0
// PRE: qp1, qp2 have the same internal number type
template <typename Quadratic_program1, typename Quadratic_program2>
bool are_equal_qp
(const Quadratic_program1 &qp1, const Quadratic_program2 &qp2)
{
bool return_val = true;
// check n
if (qp1.get_n() != qp2.get_n()) {
std::cerr << "Equality test fails with n: "
<< qp1.get_n() << " vs. " << qp2.get_n() << std::endl;
return false; // wildly wrong, abort now
}
// check m
if (qp1.get_m() != qp2.get_m()) {
std::cerr << "Equality test fails with m: "
<< qp1.get_m() << " vs. " << qp2.get_m() << std::endl;
return false; // wildly wrong, abort now
}
int n = qp1.get_n();
int m = qp1.get_m();
// check A
typename Quadratic_program1::A_iterator a1 = qp1.get_a();
typename Quadratic_program2::A_iterator a2 = qp2.get_a();
for (int j=0; j<n; ++j, ++a1, ++a2)
for (int i=0; i<m; ++i)
if (*((*a1)+i) != *((*a2)+i)) {
std::cerr << "Equality test fails with A["
<< j << "][" << i << "]: "
<< *((*a1)+i) << " vs. " << *((*a2)+i) << std::endl;
return_val = false;
}
// check b
typename Quadratic_program1::B_iterator b1 = qp1.get_b();
typename Quadratic_program2::B_iterator b2 = qp2.get_b();
for (int i=0; i<m; ++i, ++b1, ++b2)
if (*b1 != *b2) {
std::cerr << "Equality test fails with b[" << i << "]: "
<< *b1 << " vs. " << *b2 << std::endl;
return_val = false;
}
// check r
typename Quadratic_program1::R_iterator r1 = qp1.get_r();
typename Quadratic_program2::R_iterator r2 = qp2.get_r();
for (int i=0; i<m; ++i, ++r1, ++r2)
if (*r1 != *r2) {
std::cerr << "Equality test fails with r[" << i << "]: "
<< *r1 << " vs. " << *r2 << std::endl;
return_val = false;
}
// check fl, l
typename Quadratic_program1::FL_iterator fl1 = qp1.get_fl();
typename Quadratic_program2::FL_iterator fl2 = qp2.get_fl();
typename Quadratic_program1::L_iterator l1 = qp1.get_l();
typename Quadratic_program2::L_iterator l2 = qp2.get_l();
for (int j=0; j<n; ++j, ++fl1, ++fl2, ++l1, ++l2) {
if (*fl1 != *fl2) {
std::cerr << "Equality test fails with fl[" << j << "]: "
<< *fl1 << " vs. " << *fl2 << std::endl;
return_val = false;
}
if ((*fl1 == true) && (*l1 != *l2)) {
std::cerr << "Equality test fails with l[" << j << "]: "
<< *l1 << " vs. " << *l2 << std::endl;
return_val = false;
}
}
// check fu, u
typename Quadratic_program1::FU_iterator fu1 = qp1.get_fu();
typename Quadratic_program2::FU_iterator fu2 = qp2.get_fu();
typename Quadratic_program1::U_iterator u1 = qp1.get_u();
typename Quadratic_program2::U_iterator u2 = qp2.get_u();
for (int j=0; j<n; ++j, ++fu1, ++fu2, ++u1, ++u2) {
if (*fu1 != *fu2) {
std::cerr << "Equality test fails with fu[" << j << "]: "
<< *fu1 << " vs. " << *fu2 << std::endl;
return_val = false;
}
if ((*fu1 == true) && (*u1 != *u2)) {
std::cerr << "Equality test fails with u[" << j << "]: "
<< *u1 << " vs. " << *u2 << std::endl;
return_val = false;
}
}
// check d
typename Quadratic_program1::D_iterator d1 = qp1.get_d();
typename Quadratic_program2::D_iterator d2 = qp2.get_d();
for (int i=0; i<n; ++i, ++d1, ++d2)
for (int j=0; j<i+1; ++j) // only access entries on/below diagonal
if (*((*d1)+j) != *((*d2)+j)) {
std::cerr << "Equality test fails with D["
<< i << "][" << j << "]: "
<< *((*d1)+j) << " vs. " << *((*d2)+j) << std::endl;
return_val = false;
}
// check c
typename Quadratic_program1::C_iterator c1 = qp1.get_c();
typename Quadratic_program2::C_iterator c2 = qp2.get_c();
for (int j=0; j<n; ++j, ++c1, ++c2)
if (*c1 != *c2) {
std::cerr << "Equality test fails with c[" << j << "]: "
<< *c1 << " vs. " << *c2 << std::endl;
return_val = false;
}
// check c0
typename Quadratic_program1::C_entry c01 = qp1.get_c0();
typename Quadratic_program2::C_entry c02 = qp2.get_c0();
if (c01 != c02) {
std::cerr << "Equality test fails with c0: "
<< c01 << " vs. " << c02 << std::endl;
return_val = false;
}
return return_val;
}
template <typename P, typename Is_linear, typename Is_nonnegative>
void print_program
(std::ostream& out, const P& p,
const std::string& problem_name,
Is_linear is_linear,
Is_nonnegative is_nonnegative)
{
// NAME:
out << "NAME " << problem_name << "\n";
int n = p.get_n();
int m = p.get_m();
// ROWS section:
typename P::R_iterator r = p.get_r();
out << "ROWS\n"
<< " N obj\n"; // for the objective function
for (int i=0; i<m; ++i, ++r) {
if (*r == CGAL::SMALLER)
out << " L";
else if (*r == CGAL::EQUAL)
out << " E";
else if (*r == CGAL::LARGER)
out << " G";
else
CGAL_qpe_assertion_msg(false, "incorrect row-type");
out << " c" << i << "\n"; // row name is CI
}
// COLUMNS section:
typename P::A_iterator a = p.get_a();
typename P::C_iterator c = p.get_c();
typedef
typename std::iterator_traits<typename P::C_iterator>::value_type IT;
out << "COLUMNS\n";
for (int j=0; j<n; ++j, ++c, ++a) {
// make sure that variable appears here even if it has only
// zero coefficients
bool written = false;
if (!CGAL_NTS is_zero (*c)) {
out << " x" << j << " obj " << *c << "\n";
written = true;
}
for (int i=0; i<m; ++i) {
if (!CGAL_NTS is_zero (*((*a)+i))) {
out << " x" << j << " c" << i << " " << *((*a)+i) << "\n";
written = true;
}
}
if (!written)
out << " x" << j << " obj " << IT(0) << "\n";
}
// RHS section:
typename P::B_iterator b = p.get_b();
out << "RHS\n";
if (!CGAL_NTS is_zero (p.get_c0()))
out << " rhs obj " << -p.get_c0() << "\n";
for (int i=0; i<m; ++i, ++b)
if (!CGAL_NTS is_zero (*b))
out << " rhs c" << i << " " << *b << "\n";
// BOUNDS section:
QP_functions_detail::print_bounds (out, p, is_nonnegative);
// QMATRIX section:
QP_functions_detail::print_qmatrix (out, p, is_linear);
// output end:
out << "ENDATA\n";
}
template <typename Program, typename ET,
typename Is_linear,typename Is_nonnegative >
Quadratic_program_solution<ET> solve_program
(const Program &p, const ET&,
Is_linear,
Is_nonnegative,
const Quadratic_program_options& options)
{
typedef QP_solver<
Program, ET,
QP_solver_impl::QP_tags<Is_linear, Is_nonnegative> >
Solver;
const Solver* s = new Solver(p, options);
Quadratic_program_solution<ET> solution(s);
if (options.get_auto_validation()) {
// validate solution
if (options.get_verbosity() > 0)
std::cout << "Validating solution...\n";
if (!solution.solves_program(p, Is_linear(), Is_nonnegative())) {
// write log file
std::ofstream out("QP_solver.log");
out << "Error: Program solution is invalid\n"
<< " (error message: " << solution.get_error() << ")\n"
<< "------------------\n"
<< "Solution function:\n"
<< "------------------\n";
print_solution_function (out, Is_linear(), Is_nonnegative());
out << "\n"
<< "--------\n"
<< "Program:\n"
<< "--------\n";
print_program (out, p, "unsolved", Is_linear(), Is_nonnegative());
out << "--------\n"
<< "Options:\n"
<< "--------\n"
<< options << std::endl;
// print warning
std::cerr
<< "Error: Program solution is invalid "
<< "(see QP_solver.log for details)" << std::endl;
}
}
return solution;
}
}
template <typename QuadraticProgram, typename ET>
Quadratic_program_solution<ET> solve_quadratic_program
(const QuadraticProgram &qp, const ET& dummy,
const Quadratic_program_options& options)
{
return QP_functions_detail::
solve_program(qp, dummy, Tag_false(), Tag_false(), options);
}
template <typename NonnegativeQuadraticProgram, typename ET>
Quadratic_program_solution<ET> solve_nonnegative_quadratic_program
(const NonnegativeQuadraticProgram &qp, const ET& dummy,
const Quadratic_program_options& options)
{
return QP_functions_detail::
solve_program(qp, dummy, Tag_false(), Tag_true(), options);
}
template <typename LinearProgram, typename ET>
Quadratic_program_solution<ET> solve_linear_program
(const LinearProgram &lp, const ET& dummy,
const Quadratic_program_options& options)
{
return QP_functions_detail::
solve_program(lp, dummy, Tag_true(), Tag_false(), options);
}
template <typename NonnegativeLinearProgram, typename ET>
Quadratic_program_solution<ET> solve_nonnegative_linear_program
(const NonnegativeLinearProgram &lp, const ET& dummy,
const Quadratic_program_options& options)
{
return QP_functions_detail::
solve_program(lp, dummy, Tag_true(), Tag_true(), options);
}
} //namespace CGAL
#endif // CGAL_QP_FUNCTIONS_IMPL_H