Forms the virtual base class for all possible constraints given in pool format. More...
#include <ogdf/lib/abacus/constraint.h>
Public Member Functions  
Constraint (const Constraint &rhs)  
Copy constructor.  
Constraint (Master *master)  
Initializes an empty constraint.  
Constraint (Master *master, const Sub *sub, CSense::SENSE sense, double rhs, bool dynamic, bool local, bool liftable)  
Initializes a constraint.  
virtual  ~Constraint () 
ConClass *  classification (Active< Variable, Constraint > *var=nullptr) const 
Returns a pointer to the classification of the constraint.  
virtual double  coeff (const Variable *v) const =0 
Returns the coefficient of the variable v in the constraint.  
virtual double  distance (double *x, Active< Variable, Constraint > *actVar) const 
Returns the Euclidean distance of x associated with variable set actVar to the hyperplane induced by the constraint.  
virtual int  genRow (Active< Variable, Constraint > *var, Row &row) const 
Generates the row format of the constraint associated with the variable set var.  
bool  liftable () const 
Checks if the constraint is liftable.  
void  printRow (std::ostream &out, Active< Variable, Constraint > *var) const 
Writes the row format of the constraint associated with the variable set var to output stream out.  
virtual double  rhs () const 
Returns the right hand side of the constraint.  
CSense *  sense () 
Returns a pointer to the sense of the constraint.  
const CSense *  sense () const 
Returns a const pointer to the sense of the constraint.  
virtual double  slack (Active< Variable, Constraint > *variables, double *x) const 
Computes the slack of the vector x associated with the variable set variables.  
virtual bool  valid (Sub *sub) const 
Checks if the constraint is valid for the subproblem sub.  
virtual bool  violated (Active< Variable, Constraint > *variables, double *x, double *sl=nullptr) const 
Checks if a constraint is violated by a vector x associated with a variable set.  
virtual bool  violated (double slack) const 
Checks if a constraint is violated given the slack of a vector.  
Public Member Functions inherited from abacus::ConVar  
ConVar (Master *master, const Sub *sub, bool dynamic, bool local)  
Creates an instance of type ConVar.  
virtual  ~ConVar () 
bool  active () const 
Checks if the constraint/variable is active in at least one active subproblem.  
virtual bool  dynamic () const 
Return true if the constraint/variable is dynamic.  
virtual bool  equal (const ConVar *cv) const 
Should compare if the constraint/variable is identical (in a mathematical sense) with the constraint/variable cv.  
bool  global () const 
Returns true if the constraint/variable is globally valid, false otherwise.  
virtual unsigned  hashKey () const 
Should provide a key for the constraint/variable that can be used to insert it into a hash table.  
bool  local () const 
Returns true if the constraint/variable is only locally valid, false otherwise.  
virtual const char *  name () const 
Should return the name of the constraint/variable.  
virtual void  print (std::ostream &out) const 
Writes the constraint/variable to the output stream out.  
virtual double  rank () const 
The function should return a rank associated with the constraint/variable.  
const Sub *  sub () const 
Returns a const pointer to the subproblem associated with the constraint/variable.  
void  sub (Sub *sub) 
Associates a new subproblem with the constraint/variable.  
bool  expanded () const 
Returns true if the expanded format of a constraint/variable is available, false otherwise.  
virtual void  expand () const 
Expands a constraint/variable.  
virtual void  compress () const 
Compresses a constraint/variable.  
virtual bool  deletable () const 
Returns true if the constraint/variable can be destructed.  
Public Member Functions inherited from abacus::AbacusRoot  
virtual  ~AbacusRoot () 
The destructor.  
Protected Member Functions  
virtual ConClass *  classify (Active< Variable, Constraint > *var) const 
The default implementation returns a 0 pointer.  
virtual InfeasCon::INFEAS  voidLhsViolated (double newRhs) const 
Can be called if after variable elimination the left hand side of the constraint has become void and the right hand side has been adapted to newRhs.  
Protected Attributes  
ConClass *  conClass_ 
bool  liftable_ 
This member is true if also coefficients of variables which have been inactive at generation time can be computed, false otherwise.  
double  rhs_ 
The right hand side of the constraint.  
CSense  sense_ 
The sense of the constraint.  
Protected Attributes inherited from abacus::ConVar  
bool  dynamic_ 
If this member is true then the constraint/variable can be also removed from the active formulation after it is added the first time.  
bool  expanded_ 
true, if expanded version of constraint/variables available.  
bool  local_ 
true if the constraint/variable is only locally valid  
Master *  master_ 
A pointer to the corresponding master of the optimization.  
int  nActive_ 
The number of active subproblems of which the constraint/variable belongs to the set of active constraints/variables.  
int  nLocks_ 
The number of locks which have been set on the constraint/variable.  
int  nReferences_ 
The number of references to the pool slot the constraint is stored in.  
const Sub *  sub_ 
A pointer to the subproblem associated with the constraint/variable.  
Private Member Functions  
const Constraint &  operator= (const Constraint &rhs) 
Friends  
class  LpSub 
Additional Inherited Members  
Static Public Member Functions inherited from abacus::AbacusRoot  
static bool  ascii2bool (const string &str) 
Converts the string str to a boolean value.  
static bool  endsWith (const string &str, const string &end) 
Returns true if str ends with end, false otherwise.  
static double  fracPart (double x) 
Returns the absolute value of the fractional part of x.  
static const char *  onOff (bool value) 
Converts a boolean variable to the strings "on" and "off".  
Forms the virtual base class for all possible constraints given in pool format.
Constraints are one of the central items in a linearprogramming based branchandbound algorithm. This class forms the virtual base class for all possible constraints given in pool format and is derived from the common base class ConVar of all constraints and variables.
Definition at line 56 of file constraint.h.

inline 
Initializes a constraint.
master  A pointer to the corresponding master of the optimization. 
sub  A pointer to the subproblem associated with the constraint. This can be also a 0pointer. 
sense  The sense of the constraint. 
rhs  The right hand side of the constraint. 
dynamic  If this parameter is true, then the constraint can be removed from the active constraint set during the cutting plane phase of the subproblem optimization. 
local  If this parameter is true, then the constraint is considered to be only locally valid. In this case the paramument sub must not be 0 as each locally valid constraint is associated with a subproblem. 
liftable  If this parameter is true, then a lifting procedure must be available, i.e., that the coefficients of variables which have not been active at generation time of the constraint can be computed. 
Definition at line 288 of file constraint.h.

inline 
Initializes an empty constraint.
This constructor is, e.g., useful if parallel separation is applied. In this case the constraint can be constructed and receive later its data by message passing.
master  A pointer to the corresponding master of the optimization. 
Definition at line 305 of file constraint.h.

inline 
Copy constructor.
rhs  The constraint being copied. 
Definition at line 104 of file constraint.h.

inlinevirtual 
Definition at line 111 of file constraint.h.
ConClass * abacus::Constraint::classification  (  Active< Variable, Constraint > *  var = nullptr  )  const 
Returns a pointer to the classification of the constraint.
If no classification is available then we try to classify the constraint. In this case var must not be a 0pointer.
A constraint classification can only be generated if the function classify() is redefined in a derived class.

inlineprotectedvirtual 
The default implementation returns a 0 pointer.
Definition at line 260 of file constraint.h.
Returns the coefficient of the variable v in the constraint.
v  A pointer to a variable. 
Implemented in ogdf::cluster_planarity::BaseConstraint, ogdf::cluster_planarity::ChunkConnection, ogdf::cluster_planarity::ClusterKuratowskiConstraint, ogdf::cluster_planarity::CutConstraint, ogdf::cluster_planarity::MaxPlanarEdgesConstraint, ogdf::cluster_planarity::MinimalClusterConnection, ogdf::MinSteinerTreeDirectedCut< T >::EdgeConstraint, ogdf::MinSteinerTreeDirectedCut< T >::DegreeConstraint, ogdf::MinSteinerTreeDirectedCut< T >::DegreeEdgeConstraint, ogdf::MinSteinerTreeDirectedCut< T >::DirectedCutConstraint, abacus::NumCon, and abacus::RowCon.

virtual 
Returns the Euclidean distance of x associated with variable set actVar to the hyperplane induced by the constraint.
The distance of a point \(\overline{x}\) and a hyperplane \(a^T x = \beta\) can be computed in the following way: Let \(y\) be the intersection of the hyperplane \(a^T x = \beta\) and the line defined by \(\overline{x}\) and the vector \(a\). Then the distance \(d\) is the length of the vector \(\overline{x}  y\).
x  The point for which the distance should be computed. 
actVar  The variables associated with x. 

virtual 
Generates the row format of the constraint associated with the variable set var.
This function is declared virtual since faster constraint specific implementations might be desirable.
All nonzero coefficients are added to the row format. Before we generate the coefficients we try to expand the constraint, afterwards it is compressed again.
var  The variable set for which the row format should be computed. 
row  Stores the row format after calling this function. 
Reimplemented in abacus::SRowCon.

inline 
Checks if the constraint is liftable.
I.e., if the coefficients of variables inactive at generation time of the constraint can be computed later.
Definition at line 140 of file constraint.h.

private 
void abacus::Constraint::printRow  (  std::ostream &  out, 
Active< Variable, Constraint > *  var  
)  const 
Writes the row format of the constraint associated with the variable set var to output stream out.
out  The output stream. 
var  The variables for which the row format should be written. 
Returns the right hand side of the constraint.
Definition at line 130 of file constraint.h.

inline 
Returns a pointer to the sense of the constraint.
Definition at line 115 of file constraint.h.
Returns a const pointer to the sense of the constraint.
Definition at line 118 of file constraint.h.

virtual 
Computes the slack of the vector x associated with the variable set variables.
variables  The variable set associated with the vector x. 
x  The values of the variables. 
Reimplemented in abacus::SRowCon.
Checks if the constraint is valid for the subproblem sub.
Per default, this is the case if the constraint is globally valid, or the subproblem associated with the constraint is an ancestor of the subproblem sub in the enumeration tree.
sub  The subproblem for which the validity is checked. 
Definition at line 309 of file constraint.h.

virtual 
Checks if a constraint is violated by a vector x associated with a variable set.
variables  The variables associated with the vector x. 
x  The vector for which the violation is checked. 
sl  If sl is nonzero, then *sl will store the value of the violation, i.e., the slack. 
Checks if a constraint is violated given the slack of a vector.
slack  The slack of a vector. 

protectedvirtual 
Can be called if after variable elimination the left hand side of the constraint has become void and the right hand side has been adapted to newRhs.
Then this function checks if the constraint is violated.
newRhs  The right hand side of the constraint after the elimination of the variables. 
Definition at line 58 of file constraint.h.

mutableprotected 
Definition at line 269 of file constraint.h.

protected 
This member is true if also coefficients of variables which have been inactive at generation time can be computed, false otherwise.
Definition at line 275 of file constraint.h.

protected 
The right hand side of the constraint.
Definition at line 267 of file constraint.h.

protected 
The sense of the constraint.
Definition at line 265 of file constraint.h.