Package com.opttek.optquest

Class COptQuestItemSelectionVariable

java.lang.Object

com.opttek.optquest.COptQuestVariable

com.opttek.optquest.COptQuestUserControlledVariable

com.opttek.optquest.COptQuestManifoldVariable

com.opttek.optquest.COptQuestItemSelectionVariable

public final class COptQuestItemSelectionVariable
extends COptQuestManifoldVariable

An item selection variable. Its value is a selection of candidates, and the number of selected candidates is from kMin to kMax. Use an item selection variable when the decision is which candidates to include, such as which sites to open.

The engine adds the selection rule to the model as a constraint, so a solution that selects fewer than kMin or more than kMax candidates is infeasible.

Variable names: <name>@1 to <name>@n, one for each candidate. These are ordinary binary inputs. The value of each name is 1 if the candidate is selected and 0 if it is not.

In most programs, you add this variable with one of the OptQuestModel.AddItemSelectionVariable methods and read its values with OptQuestSolution.GetValue(String) and the generated names. Construct this class only when you add the variable with COptQuestOptimization.AddVariable(COptQuestVariable).

See Also:

• OptQuestModel.AddItemSelectionVariable(String, int, int)
• OptQuestModel.AddItemSelectionVariable(String, int, int, int)

Constructor Summary

Constructors

Constructor	Description
COptQuestItemSelectionVariable(String name, int n, int k)	Creates an item selection variable that selects exactly k of n candidates.
COptQuestItemSelectionVariable(String name, int n, int kMin, int kMax)	Creates an item selection variable that selects from kMin to kMax of n candidates.

Method Summary

Modifier and Type	Method	Description
List<COptQuestStringConstraint>	getConstraints()	Returns the constraints that this manifold variable adds to the model.
List<COptQuestVariable>	getInputVariables()	Returns the ordinary decision variables of this manifold variable.
List<COptQuestUserControlledVariable>	getOutputVariables()	Returns an empty list, because an item selection variable has no output variables.
List<COptQuestUserControlledVariable>	getProjectedInputVariables()	Returns an empty list, because the values of an item selection variable are ordinary inputs.

Methods inherited from class com.opttek.optquest.COptQuestUserControlledVariable

GetReplicationStatistic, GetReplicationStatisticValue, SetExclusiveRange, SetLowerBound, SetReplicationStatistic, SetUpperBound

Methods inherited from class com.opttek.optquest.COptQuestVariable

equals, GetDOELowerBound, GetDOEUpperBound, GetExclusiveLowerBoundAt, GetExclusiveUpperBoundAt, getID, GetLowerBound, GetName, GetNumberOfExclusiveRanges, GetStepSize, GetSuggestedValue, GetUpperBound, getVarRange, hashCode, isZeroOne, SetName

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

COptQuestItemSelectionVariable

public COptQuestItemSelectionVariable(String name,
 int n,
 int kMin,
 int kMax)
                               throws COptQuestException

Creates an item selection variable that selects from kMin to kMax of n candidates.

Parameters:

name - base name of the variable

n - number of candidates; must be at least 1

kMin - smallest number of candidates to select; must be at least 0

kMax - largest number of candidates to select; must be from kMin to n

Throws:

COptQuestException - if n is less than 1, or if no selection has from kMin to kMax candidates

COptQuestItemSelectionVariable

public COptQuestItemSelectionVariable(String name,
 int n,
 int k)
                               throws COptQuestException

Creates an item selection variable that selects exactly k of n candidates.

Parameters:

name - base name of the variable

n - number of candidates; must be at least 1

k - number of candidates to select; must be from 0 to n

Throws:

COptQuestException - if n is less than 1, or if k is less than 0 or greater than n

Method Details

getProjectedInputVariables

public List<COptQuestUserControlledVariable> getProjectedInputVariables()

Returns an empty list, because the values of an item selection variable are ordinary inputs.

The values are in the list that getInputVariables() returns. That list has the variables <name>@1 to <name>@n, one for each candidate.

Returns:

an empty list

getOutputVariables

public List<COptQuestUserControlledVariable> getOutputVariables()

Returns an empty list, because an item selection variable has no output variables.

The values of an item selection variable are ordinary inputs, so they are in the list that getInputVariables() returns. That list has the variables <name>@1 to <name>@n, one for each candidate.

Returns:

an empty list

getInputVariables

public List<COptQuestVariable> getInputVariables()

Description copied from class: COptQuestManifoldVariable

Returns the ordinary decision variables of this manifold variable.

The engine chooses these values directly. Your evaluator reads them as inputs. The item selection and budgeted selection types use this list, and so do the vector, matrix and N-dimensional types of continuous, integer, discrete and binary variables. For every other type, the list is empty.

Specified by:

getInputVariables in class COptQuestManifoldVariable

Returns:

fixed-size or immutable list of input variables; never null

getConstraints

public List<COptQuestStringConstraint> getConstraints()

Description copied from class: COptQuestManifoldVariable

Returns the constraints that this manifold variable adds to the model.

The engine adds these constraints to the model when the variable is added. Most manifold variable types add no constraints and return an empty list.

Overrides:

getConstraints in class COptQuestManifoldVariable

Returns:

list of constraints; never null