XPRBsos

Method Detail

• isValid

  public boolean isValid()

  Test whether a SOS is correctly defined.

       XPRBsos set1;
       if(set1.isValid() == false)
          System.out.println("Error in SOS definition.");
   

• assign

  public void assign(XPRBexpr l)
              throws java.lang.ArithmeticException

  Assign a linear expression to a SOS.

       XPRBprob expl2;
       XPRBvar[] x;
       int i;
       XPRBexpr l;
       XPRBsos set3;
       expl2 = new XPRBprob("example2");
       for(i=0;i<5;i++) x[i] = expl2.newVar("x");
       l = new XPRBexpr();
       for(i=1;i<4;i++) l.add(x[i].mul(i));
       set3.assign(l);
   

  Parameters:

  l - linear expression

  Throws:

  java.lang.ArithmeticException

• getName

  public java.lang.String getName()

  Get the name of a SOS. If the user has not defined a name the default name generated by BCL is returned.

       XPRBprob expl2;
       XPRBsos set1;
       expl2 = new XPRBprob("example2");
       set1 = expl2.newSos("sos1", XPRB.S1);
       System.out.println("SOS name:" + set1.getName());
   

  Returns:

  Name of the SOS if method executed successfully, null otherwise

• getType

  public int getType()

  Get the type of a SOS.

       XPRBprob expl2;
       XPRBsos set1;
       int stype;
       expl2 = new XPRBprob("example2");
       set1 = expl2.newSos("sos1", XPRB.S1);
       stype = set1.getType();
   

  Returns:

  Type of the SOS. Possible values:

  • XPRB.S1 Special Ordered Set of type 1
  • XPRB.S2 Special Ordered Set of type 2
  • -1 an error has occurred

• setDir

  public void setDir(int type,
                     double val)

  Set a branching directive for a SOS. This method sets any type of branching directive available in Xpress. This may be a priority for branching on a SOS (type XPRB.PR), the preferred branching direction (types XPRB.UP, XPRB.DN) or the estimated cost incurred when branching on a SOS (types XPRB.PU, XPRB.PU). Several directives of different types may be set for a single set. Method XPRBvar.setDir(int, double) may be used to set a branching directive for a variable.

       XPRBprob expl2;
       XPRBsos set1;
       expl2 = new XPRBprob("example2");
       set1 = expl2.newSos("sos1", XPRB.S1);
       set1.setDir(XPRB.PR, 5);
       set1.setDir(XPRB.DN);
   

  Parameters:

  type - directive type. Possible values:

  • XPRB.PR priority
  • XPRB.UP first branch upwards
  • XPRB.DN first branch downwards
  • XPRB.PU pseudocost on branching upwards
  • XPRB.PD pseudocost on branching downwards

  val - the value of this argument depends on the type of directive to be defined. Possible values:

  • XPRB.PR: priority value, integer between 1 (highest) and 1000 (least priority, default value)
  • XPRB.UP,XPRB.DN: no input required, choose any dummy value (e.g. 0)
  • XPRB.PU,XPRB.PD: value of pseudocost for the corresponding branch

• setDir

  public void setDir(int type)

  See Also:

  setDir(type, 0)

• addElement

  public void addElement(XPRBvar var,
                         double val)

  Add an element to a SOS. This method adds a variable and its weight coefficient to a Special Ordered Set. If the variable is already contained in the set, the indicated value is added to its weight. Note that weight coefficients must be different from 0.

       XPRBprob expl2;
       XPRBsos set1;
       XPRBvar x2;
       expl2 = new XPRBprob("example2");
       x2 = expl2.newvar("abc1", XPRB.PL, 0, INFINITY);
       set1 = expl2.newSos("sos1", XPRB.S1);
       set1.addElement(x2, 9);
   

  Parameters:

  var - a variable of type XPRBvar

  val - the corresponding weight or reference value

• addElement

  public void addElement(double val,
                         XPRBvar var)

  See Also:

  addElement(type, 0)

• delElement

  public void delElement(XPRBvar var)

  Delete an element from a SOS.

       XPRBprob expl2;
       XPRBsos set1;
       XPRBvar x2;
       expl2 = new XPRBprob("example2");
       x2 = expl2.newvar("abc1", XPRB.PL, 0, INFINITY);
       set1 = expl2.newSos("sos1", XPRB.S1);
       set1.addElement(x2, 9);
       set1.delElement(x2);
   

  Parameters:

  var - a variable of type XPRBvar

• add

  public void add(XPRBexpr l)
           throws java.lang.ArithmeticException

  Add a linear expression to a SOS. If a variable in the linear expression is already contained in the set, the indicated value is added to its weight. Constant terms in the linear expression are ignored.

       XPRBprob expl2;
       XPRBvar[] x;
       int i;
       XPRBexpr l;
       XPRBsos set3;
       expl2 = new XPRBprob("example2");
       for(i=0;i<5;i++) x[i] = expl2.newVar("x");
       l = new XPRBexpr();
       for(i=1;i<4;i++) l.add(x[i].mul(i));
       set3 = expl2.newSos("sos2", XPRB.S2);
       set3.add(l);
   

  Parameters:

  l - linear expression

  Throws:

  java.lang.ArithmeticException

• print

  public void print()

  Print out a Special Ordered Set. This method is not available in the Student Edition.

       XPRBprob expl2;
       XPRBsos set1;
       expl2 = new XPRBprob("example2");
       set1 = expl2.newSos("sos1", XPRB.S1);
       set1.print();
   

• toString

  public java.lang.String toString()

  Overrides:

  toString in class  java.lang.Object

  See Also:

  getName()