Package org.planit.gap

Class LinkBasedRelativeDualityGapFunction

java.lang.Object

org.planit.gap.GapFunction

org.planit.gap.LinkBasedRelativeDualityGapFunction

public class LinkBasedRelativeDualityGapFunction
extends GapFunction

Gap function based on the work of Bovy and Jansen (1983) who take the different between the current system travel time and the system travel time if all flow were to be assigned to the shortest paths, divided by the system travel time

Author:

markr

Field Summary

Fields

Modifier and Type	Field	Description
protected double	gap	Gap
protected double	measuredNetworkCost	Current system cost as it stands
protected double	minimumNetworkCost	Represents the total cost if all flow were to be diverted to the shortest paths for all origin-destination pairs

Fields inherited from class org.planit.gap.GapFunction

LINK_BASED_RELATIVE_GAP, stopCriterion

Constructor Summary

Constructors

Constructor	Description
LinkBasedRelativeDualityGapFunction(StopCriterion stopCriterion)	Constructor

Method Summary

Modifier and Type	Method	Description
double	computeGap()	Compute the gap
double	getGap()	Return the gap for the current iteration
double	getMeasuredNetworkCost()	Return the actual system travel time
void	increaseConvexityBound(double increaseMinimumSystemCost)	Increase convexity bound cost, i.e.
void	increaseMeasuredNetworkCost(double increaseValue)	Increase system cost, i.e.
void	reset()	Reset system travel time and convexity bound to zero

Methods inherited from class org.planit.gap.GapFunction

getStopCriterion, hasConverged

Methods inherited from class java.lang.Object

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

Field Detail

measuredNetworkCost

protected double measuredNetworkCost

Current system cost as it stands

minimumNetworkCost

protected double minimumNetworkCost

Represents the total cost if all flow were to be diverted to the shortest paths for all origin-destination pairs

gap

protected double gap

Gap

Constructor Detail

LinkBasedRelativeDualityGapFunction

public LinkBasedRelativeDualityGapFunction(StopCriterion stopCriterion)

Constructor

Parameters:

stopCriterion - StopCriterion object being used

Method Detail

computeGap

public double computeGap()

Compute the gap

Returns:

the gap for the current iteration

getMeasuredNetworkCost

public double getMeasuredNetworkCost()

Return the actual system travel time

Returns:

the actual system travel time

increaseMeasuredNetworkCost

public void increaseMeasuredNetworkCost(double increaseValue)

Increase system cost, i.e. compute it exogenously

Parameters:

increaseValue - increase in actualSystemTravelTime for this iteration

increaseConvexityBound

public void increaseConvexityBound(double increaseMinimumSystemCost)

Increase convexity bound cost, i.e. compute it exogenously

Parameters:

increaseMinimumSystemCost - the increase in minimum system cost

reset

public void reset()

Reset system travel time and convexity bound to zero

Specified by:

reset in class GapFunction

getGap

public double getGap()

Return the gap for the current iteration

Specified by:

getGap in class GapFunction

Returns:

the gap for the current iteration