com.graphhopper.util

Class DistancePlaneProjection

java.lang.Object

com.graphhopper.util.DistanceCalcEarth

com.graphhopper.util.DistancePlaneProjection

All Implemented Interfaces:

DistanceCalc

public class DistancePlaneProjection
extends DistanceCalcEarth

Calculates the approximate distance of two points on earth. Very good results if delat_lon is not too big (see DistanceCalcTest), e.g. the distance is small.

http://en.wikipedia.org/wiki/Geographical_distance#Spherical_Earth_projected_to_a_plane

http://stackoverflow.com/q/1006654

http://en.wikipedia.org/wiki/Mercator_projection#Mathematics_of_the_Mercator_projection http://gis.stackexchange.com/questions/4906/why-is-law-of-cosines-more-preferable-than-haversine-when-calculating-distance-b

Author:

Peter Karich

Field Summary

Fields inherited from class com.graphhopper.util.DistanceCalcEarth

C, KM_MILE, METERS_PER_DEGREE, R, R_EQ

Constructor Summary

Constructors

Constructor and Description
DistancePlaneProjection()

Method Summary

Modifier and Type	Method and Description
double	calcDenormalizedDist(double normedDist) Inverse to calcNormalizedDist.
double	calcDist(double fromLat, double fromLon, double toLat, double toLon) Calculates distance of (from, to) in meter.
double	calcDist3D(double fromLat, double fromLon, double fromHeight, double toLat, double toLon, double toHeight) This implements a rather quick solution to calculate 3D distances on earth using euclidean geometry mixed with Haversine formula used for the on earth distance.
double	calcNormalizedDist(double dist) Returns the specified length in normalized meter.
double	calcNormalizedDist(double fromLat, double fromLon, double toLat, double toLon) Calculates in normalized meter
String	toString()

Methods inherited from class com.graphhopper.util.DistanceCalcEarth

calcCircumference, calcCrossingPointToEdge, calcNormalizedEdgeDistance, calcNormalizedEdgeDistance3D, calcNormalizedEdgeDistanceNew, createBBox, hasElevationDiff, isCrossBoundary, isDateLineCrossOver, projectCoordinate, validEdgeDistance

Methods inherited from class java.lang.Object

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

Constructor Detail

DistancePlaneProjection

public DistancePlaneProjection()

Method Detail

calcDist

public double calcDist(double fromLat,
                       double fromLon,
                       double toLat,
                       double toLon)

Description copied from class: DistanceCalcEarth

Calculates distance of (from, to) in meter.

http://en.wikipedia.org/wiki/Haversine_formula a = sin²(Δlat/2) + cos(lat1).cos(lat2).sin²(Δlong/2) c = 2.atan2(√a, √(1−a)) d = R.c

Specified by:

calcDist in interface DistanceCalc

Overrides:

calcDist in class DistanceCalcEarth

calcDist3D

public double calcDist3D(double fromLat,
                         double fromLon,
                         double fromHeight,
                         double toLat,
                         double toLon,
                         double toHeight)

Description copied from class: DistanceCalcEarth

This implements a rather quick solution to calculate 3D distances on earth using euclidean geometry mixed with Haversine formula used for the on earth distance. The haversine formula makes not so much sense as it is only important for large distances where then the rather smallish heights would becomes negligible.

Specified by:

calcDist3D in interface DistanceCalc

Overrides:

calcDist3D in class DistanceCalcEarth

calcDenormalizedDist

public double calcDenormalizedDist(double normedDist)

Description copied from interface: DistanceCalc

Inverse to calcNormalizedDist. Returned the length in meter.

Specified by:

calcDenormalizedDist in interface DistanceCalc

Overrides:

calcDenormalizedDist in class DistanceCalcEarth

calcNormalizedDist

public double calcNormalizedDist(double dist)

Description copied from class: DistanceCalcEarth

Returns the specified length in normalized meter.

Specified by:

calcNormalizedDist in interface DistanceCalc

Overrides:

calcNormalizedDist in class DistanceCalcEarth

calcNormalizedDist

public double calcNormalizedDist(double fromLat,
                                 double fromLon,
                                 double toLat,
                                 double toLon)

Description copied from interface: DistanceCalc

Calculates in normalized meter

Specified by:

calcNormalizedDist in interface DistanceCalc

Overrides:

calcNormalizedDist in class DistanceCalcEarth

toString

public String toString()

Overrides:

toString in class DistanceCalcEarth