com.graphhopper.matching

Class MapMatching

java.lang.Object

com.graphhopper.matching.MapMatching

public class MapMatching
extends Object

This class matches real world GPX entries to the digital road network stored in GraphHopper. The Viterbi algorithm is used to compute the most likely sequence of map matching candidates. The Viterbi algorithm takes into account the distance between GPX entries and map matching candidates as well as the routing distances between consecutive map matching candidates.

See http://en.wikipedia.org/wiki/Map_matching and Newson, Paul, and John Krumm. "Hidden Markov map matching through noise and sparseness." Proceedings of the 17th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems. ACM, 2009.

Author:

Peter Karich, Michael Zilske, Stefan Holder, kodonnell

Constructor Summary

Constructors

Constructor and Description
MapMatching(com.graphhopper.GraphHopper hopper, com.graphhopper.routing.AlgorithmOptions algoOptions)

Method Summary

Modifier and Type	Method and Description
com.graphhopper.routing.Path	calcPath(MatchResult mr)
MatchResult	doWork(List<com.graphhopper.util.GPXEntry> gpxList) This method does the actual map matching.
void	setDistanceCalc(com.graphhopper.util.DistanceCalc distanceCalc)
void	setMeasurementErrorSigma(double measurementErrorSigma) Standard deviation of the normal distribution [m] used for modeling the GPS error.
void	setTransitionProbabilityBeta(double transitionProbabilityBeta) Beta parameter of the exponential distribution for modeling transition probabilities.

Methods inherited from class java.lang.Object

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

Constructor Detail

MapMatching

public MapMatching(com.graphhopper.GraphHopper hopper,
                   com.graphhopper.routing.AlgorithmOptions algoOptions)

Method Detail

setDistanceCalc

public void setDistanceCalc(com.graphhopper.util.DistanceCalc distanceCalc)

setTransitionProbabilityBeta

public void setTransitionProbabilityBeta(double transitionProbabilityBeta)

Beta parameter of the exponential distribution for modeling transition probabilities.

setMeasurementErrorSigma

public void setMeasurementErrorSigma(double measurementErrorSigma)

Standard deviation of the normal distribution [m] used for modeling the GPS error.

doWork

public MatchResult doWork(List<com.graphhopper.util.GPXEntry> gpxList)

This method does the actual map matching.

Parameters:

gpxList - the input list with GPX points which should match to edges of the graph specified in the constructor

calcPath

public com.graphhopper.routing.Path calcPath(MatchResult mr)