The MCFCplex class derives from the abstract base class MCFClass, thus sharing its (standard) interface, and solves (Linear) Min Cost Flow problems via calls to Cplex Callable Library functions. More...
#include <MCFCplex.h>
Public Types | |
 Public Types inherited from MCFClass | |
| typedef unsigned int | Index |
| index of a node or arc ( >= 0 ) | |
| typedef Index * | Index_Set |
| set (array) of indices | |
| typedef const Index | cIndex |
| a read-only index | |
| typedef cIndex * | cIndex_Set |
| read-only index array | |
| typedef double | FNumber |
| type of arc flow | |
| typedef FNumber * | FRow |
| vector of flows | |
| typedef const FNumber | cFNumber |
| a read-only flow | |
| typedef cFNumber * | cFRow |
| read-only flow array | |
| typedef double | CNumber |
| type of arc flow cost | |
| typedef CNumber * | CRow |
| vector of costs | |
| typedef const CNumber | cCNumber |
| a read-only cost | |
| typedef cCNumber * | cCRow |
| read-only cost array | |
| typedef double | FONumber |
| type of the objective function: has to hold sums of products of FNumber(s) by CNumber(s) | |
| typedef const FONumber | cFONumber |
| a read-only o.f. value | |
| typedef MCFState * | MCFStatePtr |
| pointer to a MCFState | |
Public Member Functions | |
| MCFCplex (cIndex nmx=0, cIndex mmx=0, CPXENVptr extenv=NULL) | |
| Constructor of the class. More... | |
| void | LoadNet (cIndex nmx=0, cIndex mmx=0, cIndex pn=0, cIndex pm=0, cFRow pU=NULL, cCRow pC=NULL, cFRow pDfct=NULL, cIndex_Set pSn=NULL, cIndex_Set pEn=NULL) |
| Inputs a new network, as in MCFClass::LoadNet(). More... | |
| virtual void | SetPar (int par, int val) |
| Set integer parameters of the algorithm. More... | |
| virtual void | SetPar (int par, double val) |
| Set float parameters of the algorithm. More... | |
| virtual void | GetPar (int par, int &val) |
| This method returns one of the integer parameter of the algorithm. More... | |
| CPXENVptr | GetCplexEnv (void) |
| Returns a pointer to the internal Cplex environment. More... | |
| Public Member Functions inherited from MCFClass | |
| MCFClass (cIndex nmx=0, cIndex mmx=0) | |
| Constructor of the class. More... | |
| virtual void | LoadDMX (istream &DMXs, bool IsQuad=false) |
| Read a MCF instance in DIMACS standard format from the istream. More... | |
| virtual void | PreProcess (void) |
| Extract a smaller/easier equivalent MCF problem. More... | |
| virtual void | GetPar (int par, double &val) |
| This method returns one of the integer parameter of the algorithm. More... | |
| virtual void | SetMCFTime (bool TimeIt=true) |
| Allocate an OPTtimers object [see OPTtypes.h] to be used for timing the methods of the class. More... | |
| int | MCFGetStatus (void) |
| Returns an int describing the current status of the MCF solver. More... | |
| virtual cFRow | MCFGetX (void) |
| Return a read-only pointer to an internal data structure containing the flow solution in "dense" format. More... | |
| virtual bool | HaveNewX (void) |
| Return true if a different (approximately) optimal primal solution is available. More... | |
| virtual cCRow | MCFGetPi (void) |
| Return a read-only pointer to an internal data structure containing the node potentials. More... | |
| virtual bool | HaveNewPi (void) |
| Return true if a different (approximately) optimal dual solution is available. More... | |
| virtual cCRow | MCFGetRC (void) |
| Return a read-only pointer to an internal data structure containing the reduced costs. More... | |
| virtual FONumber | MCFGetDFO (void) |
| Return the objective function value of the dual solution currently returned by MCFGetPi() / MCFGetRC(). More... | |
| virtual FNumber | MCFGetUnfCut (Index_Set Cut) |
| Return an unfeasibility certificate. More... | |
| virtual Index | MCFGetUnbCycl (Index_Set Pred, Index_Set ArcPred) |
| Return an unboundedness certificate. More... | |
| virtual MCFStatePtr | MCFGetState (void) |
| Save the state of the MCF solver. More... | |
| virtual void | MCFPutState (MCFStatePtr S) |
| Restore the solver to the state in which it was when the state `S' was created with MCFGetState() [see above]. More... | |
| void | TimeMCF (double &t_us, double &t_ss) |
| Time the code. More... | |
| double | TimeMCF (void) |
| Like TimeMCF(double,double) [see above], but returns the total time. More... | |
| void | CheckPSol (void) |
| Check that the primal solution returned by the solver is primal feasible. More... | |
| void | CheckDSol (void) |
| Check that the dual solution returned by the solver is dual feasible. More... | |
| Index | MCFnmax (void) |
| Return the maximum number of nodes for this instance of MCFClass. More... | |
| Index | MCFmmax (void) |
| Return the maximum number of arcs for this instance of MCFClass. More... | |
| Index | MCFn (void) |
| Return the number of nodes in the current graph. More... | |
| Index | MCFm (void) |
| Return the number of arcs in the current graph. More... | |
| virtual cIndex_Set | MCFSNdes (void) |
| Return a read-only pointer to an internal vector containing the starting (tail) nodes for each arc. More... | |
| virtual cIndex_Set | MCFENdes (void) |
| Return a read-only pointer to an internal vector containing the ending (head) nodes for each arc. More... | |
| virtual cCRow | MCFCosts (void) |
| Return a read-only pointer to an internal vector containing the arc costs. More... | |
| virtual cCRow | MCFQCoef (void) |
| Return a read-only pointer to an internal vector containing the arc costs. More... | |
| virtual cFRow | MCFUCaps (void) |
| Return a read-only pointer to an internal vector containing the arc capacities. More... | |
| virtual cFRow | MCFDfcts (void) |
| Return a read-only pointer to an internal vector containing the node deficits. More... | |
| virtual void | WriteMCF (ostream &oStrm, int frmt=0) |
| Write the current MCF problem to an ostream. More... | |
| virtual | ~MCFClass () |
| Destructor of the class. More... | |
Additional Inherited Members | |
| Protected Member Functions inherited from MCFClass | |
| template<class T > | |
| bool | ETZ (T x, const T eps) |
| true if flow x is equal to zero (possibly considering tolerances). More... | |
| template<class T > | |
| bool | GTZ (T x, const T eps) |
| true if flow x is greater than zero (possibly considering tolerances). More... | |
| template<class T > | |
| bool | GEZ (T x, const T eps) |
| true if flow x is greater than or equal to zero (possibly considering tolerances). More... | |
| template<class T > | |
| bool | LTZ (T x, const T eps) |
| true if flow x is less than zero (possibly considering tolerances). More... | |
| template<class T > | |
| bool | LEZ (T x, const T eps) |
| true if flow x is less than or equal to zero (possibly considering tolerances). More... | |
| template<class T > | |
| bool | GT (T x, T y, const T eps) |
| true if flow x is greater than flow y (possibly considering tolerances). | |
| template<class T > | |
| bool | LT (T x, T y, const T eps) |
| true if flow x is less than flow y (possibly considering tolerances). More... | |
| Protected Attributes inherited from MCFClass | |
| Index | n |
| total number of nodes | |
| Index | nmax |
| maximum number of nodes | |
| Index | m |
| total number of arcs | |
| Index | mmax |
| maximum number of arcs | |
| int | status |
| return status, see the comments to MCFGetStatus() above. More... | |
| bool | Senstv |
| true <=> the latest optimal solution should be exploited | |
| OPTtimers * | MCFt |
| timer for performances evaluation | |
| FNumber | EpsFlw |
| precision for comparing arc flows / capacities | |
| FNumber | EpsDfct |
| precision for comparing node deficits | |
| CNumber | EpsCst |
| precision for comparing arc costs | |
| double | MaxTime |
| max time (in seconds) in which MCF Solver can find an optimal solution (0 = no limits) | |
| int | MaxIter |
| max number of iterations in which MCF Solver can find an optimal solution (0 = no limits) | |
Detailed Description
The MCFCplex class derives from the abstract base class MCFClass, thus sharing its (standard) interface, and solves (Linear) Min Cost Flow problems via calls to Cplex Callable Library functions.
Member Enumeration Documentation
| enum MCFCParam |
Public enum describing the possible parameters of the MCF solver, "extended" from MCFClass::MCFParam, to be used with the methods SetPar() and GetPar().
| Enumerator | |
|---|---|
| kQPMethod |
solution method |
Constructor & Destructor Documentation
Constructor of the class.
For the meaning of nmx and mmx see MCFClass::MCFClass().
If extenv != NULL, it is taken as a pointer to a valid Cplex environment [see GetCplexEnv() below] that will be used for all the lifetime of the object. Otherwise, a Cplex environment is possibly initialized in the constructor. The environment is shared among all the active instances of MCFCplex objects; this is done in order to save on the number of (costly) Cplex licenses required to have multiple MCF solvers active at the same time, since any environment consumes a licence. Thus, the environment is actually initialized only when the first instance is constructed, and it is released when the last destructor (of an instance using it) is invoked.
The possibility of passing an external environment is let because having all the instances to share the same environment has the drawback that all changes made to optimization parameters of the environment [see SetPar() below] are "seen" be all active instances, even though the changes are invoked for one specific object. If for some reason this is unacceptable, the user should provide each "sensitive" instance with its own private environment, letting all the others to share the "static" one. Of course, it is then user's responsibility to initialize and free the environment.
Member Function Documentation
|
virtual |
Inputs a new network, as in MCFClass::LoadNet().
Passing pC[ i ] == C_INF means that the arc `i' does not exist in the problem. These arcs are just "closed" and their cost is set to 0: this is done for being (if DYNMC_MCF_CPX > 0) subsequently capable of "opening" them back with OpenArc(). If the corresponding pU[ i ] is == F_INF then the arc is just "deleted".
Implements MCFClass.
|
inlinevirtual |
Set integer parameters of the algorithm.
- Parameters
-
par is the parameter to be set; value is the value to assign to the parameter.
Apart from the parameters of the base class, this method handles:
- kQPMethod: the alorithm used to solve the QP, possible values are defined in the enum QPMethod.
- <any other>="">: any unrecognized value is taken to be one of the the many "int" algorithmic parameters of Cplex and passed right away via CPXsetintparam() [see the documentation in the Cplex manual for details.
Reimplemented from MCFClass.
References MCFClass::SetPar().
|
inlinevirtual |
Set float parameters of the algorithm.
- Parameters
-
par is the parameter to be set; value is the value to assign to the parameter.
Apart from the parameters of the base class, this method handles:
- <any other>="">: any unrecognized value is taken to be one of the the many "int" algorithmic parameters of Cplex and passed right away via CPXsetintparam() [see the documentation in the Cplex manual for details.
Reimplemented from MCFClass.
References MCFClass::SetPar().
|
inlinevirtual |
This method returns one of the integer parameter of the algorithm.
- Parameters
-
par is the parameter to return [see SetPar( int ) for comments]; val upon return, it will contain the value of the parameter.
Apart from the parameters of the base class, this method handles kQPMethod.
Reimplemented from MCFClass.
References MCFClass::GetPar().
|
inline |
Returns a pointer to the internal Cplex environment.
This method is provided as an alternative to the two forms of SetPar() [see above]; by getting the pointer to the internal Cplex environment with GetCplexEnv(), CPXset***param() can be called directly. This also allows to perform any other operation with the environment, such as reading the value of the parameters with CPXgetintparam() and CPXgetdbqparam(), so care must be taken.
The returned pointer is the same passed to the constructor [see above], if any; otherwise it is the "static" environment shared by all the active MCFCplex instances. In the latter case, any change in the environment simultaneously affect all the existing (and future) MCFCplex instances which have not been given a "private" environment.
References MCFClass::MCFQCoef().
