cgal/Packages/QP_solver/include/CGAL/QP_partial_exact_pricing.h

152 lines
3.8 KiB
C++

// ============================================================================
//
// Copyright (c) 1997-2003 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------------
//
// release : $CGAL_Revision: CGAL-I $
// release_date : $CGAL_Date$
//
// file : include/CGAL/QP_engine/QPE_partial_exact_pricing.h
// package : $CGAL_Package: QP_engine $
// chapter : Quadratic Programming Engine
//
// revision : 3.0alpha
// revision_date : 2003/08
//
// author(s) : Sven Schönherr <sven@inf.fu-berlin.de>
// coordinator : ETH Zürich (Bernd Gärtner <gaertner@inf.ethz.ch>)
//
// implementation: Pricing Strategy with partial exact pricing
// ============================================================================
#ifndef CGAL_QPE_PARTIAL_EXACT_PRICING_H
#define CGAL_QPE_PARTIAL_EXACT_PRICING_H
// includes
#include <CGAL/QP_engine/QPE__partial_base.h>
CGAL_BEGIN_NAMESPACE
// =================
// class declaration
// =================
template < class Rep_ >
class QPE_partial_exact_pricing;
// ===============
// class interface
// ===============
template < class Rep_ >
class QPE_partial_exact_pricing : public QPE__partial_base<Rep_> {
// self
typedef Rep_ Rep;
typedef QPE_pricing_strategy<Rep> Base;
typedef QPE__partial_base<Rep> Partial_base;
typedef QPE_partial_exact_pricing<Rep> Self;
// types from the pricing base class
typedef typename Base::ET ET;
public:
// creation
QPE_partial_exact_pricing( bool randomize = false,
Random& random = default_random);
// operations
int pricing( );
};
// ----------------------------------------------------------------------------
// =============================
// class implementation (inline)
// =============================
// construction
template < class Rep_ > inline
QPE_partial_exact_pricing<Rep_>::
QPE_partial_exact_pricing( bool randomize, Random& random)
: Base( "partial exact"),
Partial_base( randomize, random)
{ }
// operations
template < class Rep_ >
int QPE_partial_exact_pricing<Rep_>::
pricing( )
{
Partial_base::Index_iterator it, min_it;
ET mu, min_mu = 0;
// loop over all active non-basic variables
CGAL_qpe_debug {
vout() << "active variables:" << std::endl;
}
for ( it = active_set_begin(); it != active_set_end(); ++it) {
// compute mu_j
mu = mu_j( *it);
CGAL_qpe_debug {
vout() << " mu_" << *it << ": " << mu << std::endl;
}
// new minimum?
if ( mu < min_mu) { min_it = it; min_mu = mu; }
}
// no entering variable found so far?
if ( ( min_mu == et0) && ( inactive_set_begin() < inactive_set_end())) {
// loop over all inactive non-basic variables
CGAL_qpe_debug {
vout() << "inactive variables:" << std::endl;
}
Index_iterator active_it;
for ( it = inactive_set_begin(); it != inactive_set_end(); ++it) {
// compute mu_j
mu = mu_j( *it);
CGAL_qpe_debug {
vout() << " mu_" << *it << ": " << mu << std::endl;
}
// candidate for entering?
if ( mu < et0) {
// make variable active
active_it = it;
activating( active_it);
// new minimum?
if ( mu < min_mu) { min_it = active_it; min_mu = mu; }
}
}
}
vout() << std::endl;
// return index of entering variable, if any
if ( min_mu < et0) {
int j = *min_it;
entering_basis( min_it);
return j;
}
// no entering variable found
return -1;
}
CGAL_END_NAMESPACE
#endif // CGAL_QPE_PARTIAL_EXACT_PRICING_H
// ===== EOF ==================================================================