ILOG CPLEX C++ API 9.0 Reference Manual

IloCplex
This method sets the preferred branching direction for variable var to dir. This setting
will cause CPLEX first to explore the branch indicated by dir after branching on
variable var.
public void setDirections(const IloNumVarArray var,
const IloCplex::BranchDirectionArray dir)
This method sets the preferred branching direction for each variable in the array var to
the corresponding value in the array dir. This will cause CPLEX to first explore the
branch indicated by dir[i] after branching on variable var[i].
public void setFormulationBigValue(IloNum v)
This method sets the large value used to set a bound on any otherwise unbounded
expressions appearing in logical constraints. Such a value is sometimes referred to as
Big M. By default, it is set to 1e6.
The method getFormulationBigValue returns the current setting of the large
value.
In order to transform a logical constraint autmatically into an equivalent MIP
formulation, it is sometimes necessary to set a finite upper or lower bound on an
otherwise unbounded term. When such a bound does not already exist, CPLEX uses the
value set by this method for that purpose. For example, consider the following
disjunction (that is, an or-statement):
(x == 1) || (x 2)
It is necessary to have an upper bound on x. If the upper bound on x is
IloInfinity, CPLEX will use the value controlled by this method in the
transformed representation of logical formulations.
public void setFormulationEpsValue(IloNum eps)
This method sets the epsilon value that is used to model strict relations. In order to
model a strict inequality such as x < b in a MIP, IloCplex uses x ≤ b - eps as a
surrogate, where eps is the value controlled by this method.
public void setParam(IloCplex::BoolParam parameter,
IloBool value)
This method sets parameter to value in the invoking algorithm. See the ILOG
CPLEX User's Manual for more detailed information about parameters and for
examples of their use.
public void setPriorities(const IloNumVarArray var,
const IloNumArray pri)
This method sets the priority order for all variables in the array var to the
corresponding value in the array pri. During branching, integer variables with higher
ILOG CPLEX C++ API 9.0 REFERENCE M ANUAL 72