Function ConstraintVariables(Contraints)

ConstraintVariables

The function ConstraintVariables returns all the symbolic variables that are referred in a certain collection of constraints, including the variables that are referred in the definitions of these variables.

ConstraintVariables(
     Contraints      ! (input) a subset of AllConstraints
     )

Arguments

Contraints

The set of constraints for which you want to retrieve the referred variables.

Note

This function operates on the compiled definition of constraints; it will skip inline variables.

Example

Model Main_cv {
    Variable x {
        Range: free;
    }
    Variable y {
        Range: free;
    }
    Variable z {
        Range: free;
        Property: Inline;
        Definition: x + y;
    }
    Constraint c {
        Definition: z > 0;
    }
    Set S {
        SubsetOf: AllConstraints;
        Index: i;
        Definition: data { c };
    }
    Set T {
        SubsetOf: AllVariables;
        Index: j;
    }
    Set U {
        SubsetOf: AllVariables;
        Index: k;
    }
    Set setje {
        Index: ii;
        Definition: data { a, b };
    }
    Parameter P {
        IndexDomain: ii;
        Definition: data { a : 3,  b : 4 };
    }
    ElementParameter colPar {
        IndexDomain: ii;
        Range: AllColors;
        Definition: data { a : red,  b : yellow };
    }
    Procedure MainInitialization;
    Procedure MainExecution {
        Body: {
            T := ConstraintVariables( S );
            U := ReferencedIdentifiers( S, AllAttributeNames, recursive: 1 );
            display T, U ;
        }
    }
    Procedure MainTermination {
        Body: {
            return 1 ;
        }
    }
}

Running MainExecution will create the following listing file:

T := data { x, y } ;

U := data { x, y, z } ;

Because z is an inline variable.

Return Value

The function returns a subset of the set AllVariables, containing the variables found.

See also

• The function VariableConstraints and ReferencedIdentifiers.