org.jacop.constraints.netflow

Class NetworkBuilder

java.lang.Object

org.jacop.constraints.netflow.NetworkBuilder

public class NetworkBuilder
extends Object

A builder class for the network flow constraints. Models should use or inherit from this class to build a network.

Version:

4.9

Author:

Robin Steiger and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
List<Arc>	arcList
IntVar	costVariable
List<VarHandler>	handlerList
List<org.jacop.constraints.netflow.simplex.Node>	nodeList

Constructor Summary

Constructors

Constructor and Description
NetworkBuilder()
NetworkBuilder(IntVar costVariable)

Method Summary

Modifier and Type	Method and Description
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, int weight)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, int weight, int capacity)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, int weight, int lowerCapacity, int upperCapacity)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, int weight, IntVar xVar)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, IntVar wVar, int lowerCapacity, int upperCapacity)
Arc	addArc(org.jacop.constraints.netflow.simplex.Node from, org.jacop.constraints.netflow.simplex.Node to, IntVar wVar, IntVar xVar)
org.jacop.constraints.netflow.simplex.Node	addNode()
org.jacop.constraints.netflow.simplex.Node	addNode(int balance)
org.jacop.constraints.netflow.simplex.Node	addNode(String name)
org.jacop.constraints.netflow.simplex.Node	addNode(String name, int balance)
NetworkFlow	build()
ArrayList<IntVar>	listVariables()
List<Constraint>	primitiveDecomposition(Store store) Generally speaking, especially in case of multiple arcs between two nodes and structure constraints imposed on arcs makes it hard to decompose network flow constraint into primitive ones.
void	setCostVariable(IntVar costVariable)
org.jacop.constraints.netflow.simplex.Node[][]	valueGraph(IntVar[] vars, IntDomain[] domains) Returns two arrays containing the nodes for each variable and the nodes for each domain, respectively.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

costVariable

public IntVar costVariable

nodeList

public final List<org.jacop.constraints.netflow.simplex.Node> nodeList

arcList

public final List<Arc> arcList

handlerList

public final List<VarHandler> handlerList

Constructor Detail

NetworkBuilder

public NetworkBuilder()

NetworkBuilder

public NetworkBuilder(IntVar costVariable)

Method Detail

setCostVariable

public void setCostVariable(IntVar costVariable)

addNode

public org.jacop.constraints.netflow.simplex.Node addNode()

addNode

public org.jacop.constraints.netflow.simplex.Node addNode(int balance)

addNode

public org.jacop.constraints.netflow.simplex.Node addNode(String name)

addNode

public org.jacop.constraints.netflow.simplex.Node addNode(String name,
                                                          int balance)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  IntVar wVar,
                  IntVar xVar)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  int weight,
                  IntVar xVar)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  IntVar wVar,
                  int lowerCapacity,
                  int upperCapacity)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  int weight,
                  int lowerCapacity,
                  int upperCapacity)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  int weight,
                  int capacity)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to,
                  int weight)

addArc

public Arc addArc(org.jacop.constraints.netflow.simplex.Node from,
                  org.jacop.constraints.netflow.simplex.Node to)

valueGraph

public org.jacop.constraints.netflow.simplex.Node[][] valueGraph(IntVar[] vars,
                                                                 IntDomain[] domains)

Returns two arrays containing the nodes for each variable and the nodes for each domain, respectively.

Parameters:

vars - varibales for nodes

domains - nodes for each variable

Returns:

two arrays containing the nodes for each variable and the nodes for each domain, respectively

listVariables

public ArrayList<IntVar> listVariables()

build

public NetworkFlow build()

primitiveDecomposition

public List<Constraint> primitiveDecomposition(Store store)

Generally speaking, especially in case of multiple arcs between two nodes and structure constraints imposed on arcs makes it hard to decompose network flow constraint into primitive ones. Since, the decomposition introduces new variables and removal of artificial solutions is not practically achievable in all cases it is possible that decomposition will have more solutions due to the fact that decomposition may use more expensive arcs to transfer the flow.

Parameters:

store - current store

Returns:

decomposed network using primitive constraints