IBM ILOG OPL JavaScript Reference: Class IloConstraint

Class IloConstraint

IloConstraint

Caution:: For technical reasons, the lower and upper bound properties LB and UB are currently accessible only during postprocessing and flow control in constraints assigned in a forall declaration. The undefined value is returned instead. You can nevertheless modify the bounds.

Example:

dvar float x in 5..20;
dvar float y in 0..20;

maximize x+y;

subject to
{
 ct1:2*x+y<=10;
 ct2:x<=7;  
}
 
execute
{
 writeln( ct1.name," ",ct1.UB," ",ct1.LB," ",ct1.dual," ",ct1.slack); 
 writeln( ct2.name," ",ct2.UB," ",ct2.LB," ",ct2.dual," ",ct2.slack); 
}

After execution, the Scripting log shows:

ct1 10 -Infinity 1 0
ct2 7 -Infinity 0 2

Iterating properties:: Default behavior.

Index resolution:: Default behavior.

OPL type:: constraint

Property Summary
Field Attributes	Field Name and Description
postprocessing flow control	dual Dual value in a solution.
postprocessing flow control (write only)	LB Lower bound.
postprocessing flow control	name Name of the constraint.
postprocessing flow control	slack Slack value in a solution.
postprocessing flow control (write only)	UB Upper bound.

Method Summary
Method Attributes	Method Name and Description
all	setBounds(lb, ub) Sets `lb` as the lower bound and `ub` as the upper bound of the invoking numeric variable.
all	setCoef(dvar, coef) Changes the coefficient of a decision variable in the invoking constraint.

Property Detail

dual

{float} dual

Dual value in a solution. Exists only for linear problems with CPLEX.

Available for:: postprocessing; flow control

{float} LB

Lower bound.

Available for:: postprocessing; flow control (write only)

name

{string} name

Name of the constraint.

Available for:: postprocessing; flow control

slack

{float} slack

Slack value in a solution.

Exists only for CPLEX linear mixed integer problems.

Available for:: postprocessing; flow control

{float} UB

Upper bound.

Available for:: postprocessing; flow control (write only)

Method Detail

setBounds

setBounds(lb, ub)

Sets lb as the lower bound and ub as the upper bound of the invoking numeric variable.

The member functionsetBounds notifies Concert Technology algorithms about the change of bounds in the numeric variable.

Parameters:: lb - Lower bound.; ub - Upper bound.

See also:: IloCplex

Available for:: all

setCoef

setCoef(dvar, coef)

Changes the coefficient of a decision variable in the invoking constraint. This method is limited to constraints that use simple real linear expressions with no aggregation. In other cases, use the method from the IloCplex class.

Parameters:: dvar - Decision variable.; coef - The new linear coefficient.

See also:: IloCplex

Available for:: all