lemon/lp_base.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Wed, 29 Apr 2009 03:15:24 +0200
changeset 636 6c408d864fa1
parent 459 ed54c0d13df0
child 761 f1398882a928
permissions -rw-r--r--
Support negative costs and bounds in NetworkSimplex (#270)

* The interface is reworked to support negative costs and bounds.
- ProblemType and problemType() are renamed to
SupplyType and supplyType(), see also #234.
- ProblemType type is introduced similarly to the LP interface.
- 'bool run()' is replaced by 'ProblemType run()' to handle
unbounded problem instances, as well.
- Add INF public member constant similarly to the LP interface.
* Remove capacityMap() and boundMaps(), see also #266.
* Update the problem definition in the MCF module.
* Remove the usage of Circulation (and adaptors) for checking feasibility.
Check feasibility by examining the artifical arcs instead (after solving
the problem).
* Additional check for unbounded negative cycles found during the
algorithm (it is possible now, since negative costs are allowed).
* Fix in the constructor (the value types needn't be integer any more),
see also #254.
* Improve and extend the doc.
* Rework the test file and add test cases for negative costs and bounds.
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 ///\file
    20 ///\brief The implementation of the LP solver interface.
    21 
    22 #include <lemon/lp_base.h>
    23 namespace lemon {
    24 
    25   const LpBase::Value LpBase::INF =
    26     std::numeric_limits<LpBase::Value>::infinity();
    27   const LpBase::Value LpBase::NaN =
    28     std::numeric_limits<LpBase::Value>::quiet_NaN();
    29 
    30 } //namespace lemon