com.graphhopper.routing

Class AlternativeRoute

java.lang.Object

com.graphhopper.routing.AbstractBidirAlgo

com.graphhopper.routing.AbstractNonCHBidirAlgo

com.graphhopper.routing.AStarBidirection

com.graphhopper.routing.AlternativeRoute

All Implemented Interfaces:

BidirRoutingAlgorithm, RoutingAlgorithm

public class AlternativeRoute
extends AStarBidirection
implements RoutingAlgorithm

This class implements the alternative paths search using the "plateau" and partially the "penalty" method described in the following papers.

• Choice Routing Explanation - Camvit 2009: http://www.camvit.com/camvit-technical-english/Camvit-Choice-Routing-Explanation-english.pdf
• and refined in: Alternative Routes in Road Networks 2010: http://www.cs.princeton.edu/~rwerneck/papers/ADGW10-alternatives-sea.pdf
• other ideas 'Improved Alternative Route Planning', 2013: https://hal.inria.fr/hal-00871739/document
• via point 'storage' idea 'Candidate Sets for Alternative Routes in Road Networks', 2013: https://algo2.iti.kit.edu/download/s-csarrn-12.pdf
• Alternative route graph construction 2011: http://algo2.iti.kit.edu/download/altgraph_tapas_extended.pdf

Note: This algorithm can be slow for longer routes and alternatives are only really practical in combination with CH, see #2566

Author:

Peter Karich

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AlternativeRoute.AlternativeInfo

Field Summary

Fields inherited from class com.graphhopper.routing.AbstractNonCHBidirAlgo

additionalEdgeFilter, edgeExplorer, graph, nodeAccess, weighting

Fields inherited from class com.graphhopper.routing.AbstractBidirAlgo

bestBwdEntry, bestFwdEntry, bestWeight, bestWeightMapFrom, bestWeightMapOther, bestWeightMapTo, currFrom, currTo, finishedFrom, finishedTo, from, fromOutEdge, maxVisitedNodes, to, toInEdge, traversalMode, updateBestPath

Constructor Summary

Constructors

Constructor and Description
AlternativeRoute(Graph graph, Weighting weighting, TraversalMode traversalMode, PMap hints)

Method Summary

Modifier and Type	Method and Description
List<AlternativeRoute.AlternativeInfo>	calcAlternatives(int from, int to)
List<AlternativeRoute.AlternativeInfo>	calcAlternatives(Path bestPath, int maxPaths, double maxWeightFactor, double weightInfluence, double maxShareFactor, double shareInfluence, double minPlateauFactor, double plateauInfluence)
List<Path>	calcPaths(int from, int to) Calculates multiple possibilities for a path.
boolean	finished()
String	getName()
Path	searchBest(int from, int to)
void	setMaxVisitedNodes(int numberOfNodes) Limit the search to numberOfNodes.

Methods inherited from class com.graphhopper.routing.AStarBidirection

calcWeight, createEntry, createStartEntry, getApproximation, setApproximation

Methods inherited from class com.graphhopper.routing.AbstractNonCHBidirAlgo

accept, createEmptyPath, createPathExtractor, extractPath, fillEdgesFromUsingFilter, fillEdgesToUsingFilter, getInEdgeWeight, postInitFrom, postInitTo, toString

Methods inherited from class com.graphhopper.routing.AbstractBidirAlgo

bwdSearchCanBeStopped, calcPath, calcPath, checkAlreadyRun, fromEntryCanBeSkipped, fwdSearchCanBeStopped, getCurrentFromWeight, getCurrentToWeight, getIncomingEdge, getVisitedNodes, initCollections, initFrom, initTo, isMaxVisitedNodesExceeded, postInit, runAlgo, setUpdateBestPath, toEntryCanBeSkipped, updateBestPath

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.graphhopper.routing.RoutingAlgorithm

calcPath, getVisitedNodes

Methods inherited from interface com.graphhopper.routing.BidirRoutingAlgorithm

calcPath

Constructor Detail

AlternativeRoute

public AlternativeRoute(Graph graph,
                        Weighting weighting,
                        TraversalMode traversalMode,
                        PMap hints)

Method Detail

setMaxVisitedNodes

public void setMaxVisitedNodes(int numberOfNodes)

Description copied from interface: RoutingAlgorithm

Limit the search to numberOfNodes. See #681

Specified by:

setMaxVisitedNodes in interface RoutingAlgorithm

Overrides:

setMaxVisitedNodes in class AbstractBidirAlgo

calcAlternatives

public List<AlternativeRoute.AlternativeInfo> calcAlternatives(int from,
                                                               int to)

calcPaths

public List<Path> calcPaths(int from,
                            int to)

Description copied from interface: RoutingAlgorithm

Calculates multiple possibilities for a path.

Specified by:

calcPaths in interface RoutingAlgorithm

Overrides:

calcPaths in class AbstractBidirAlgo

See Also:

RoutingAlgorithm.calcPath(int, int)

getName

public String getName()

Specified by:

getName in interface RoutingAlgorithm

Overrides:

getName in class AStarBidirection

Returns:

name of this algorithm

finished

public boolean finished()

Overrides:

finished in class AStarBidirection

searchBest

public Path searchBest(int from,
                       int to)

calcAlternatives

public List<AlternativeRoute.AlternativeInfo> calcAlternatives(Path bestPath,
                                                               int maxPaths,
                                                               double maxWeightFactor,
                                                               double weightInfluence,
                                                               double maxShareFactor,
                                                               double shareInfluence,
                                                               double minPlateauFactor,
                                                               double plateauInfluence)

Returns:

the information necessary to handle alternative paths. Note that the paths are not yet extracted.