com.graphhopper.util

Interface DistanceCalc

All Known Implementing Classes:

DistanceCalc2D, DistanceCalc3D, DistanceCalcEarth, DistancePlaneProjection

public interface DistanceCalc

Calculates the distance of two points or one point and an edge on earth via haversine formula. Allows subclasses to implement less or more precise calculations.

See http://en.wikipedia.org/wiki/Haversine_formula

Author:

Peter Karich

Method Summary

Modifier and Type	Method and Description
double	calcCircumference(double lat)
GHPoint	calcCrossingPointToEdge(double r_lat_deg, double r_lon_deg, double a_lat_deg, double a_lon_deg, double b_lat_deg, double b_lon_deg)
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	calcNormalizedDist(double dist) Returns the specified length in normalized meter.
double	calcNormalizedDist(double fromLat, double fromLon, double toLat, double toLon) Calculates in normalized meter
double	calcNormalizedEdgeDistance(double r_lat_deg, double r_lon_deg, double a_lat_deg, double a_lon_deg, double b_lat_deg, double b_lon_deg) This method calculates the distance from r to edge (a, b) where the crossing point is c
BBox	createBBox(double lat, double lon, double radiusInMeter)
boolean	isCrossBoundary(double lon1, double lon2)
GHPoint	projectCoordinate(double lat, double lon, double distanceInMeter, double headingClockwiseFromNorth) This methods creates a point (lat, lon in degrees) in a certain distance and direction from the specified point (lat, lon in degrees).
boolean	validEdgeDistance(double r_lat_deg, double r_lon_deg, double a_lat_deg, double a_lon_deg, double b_lat_deg, double b_lon_deg) This method decides for case 1: if we should use distance(r to edge) where r=(lat,lon) or case 2: min(distance(r to a), distance(r to b)) where edge=(a to b).

Method Detail

createBBox

BBox createBBox(double lat,
                double lon,
                double radiusInMeter)

calcCircumference

double calcCircumference(double lat)

calcDist

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

Calculates distance of (from, to) in meter.

calcNormalizedDist

double calcNormalizedDist(double dist)

Returns the specified length in normalized meter.

calcDenormalizedDist

double calcDenormalizedDist(double normedDist)

Inverse to calcNormalizedDist. Returned the length in meter.

calcNormalizedDist

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

Calculates in normalized meter

validEdgeDistance

boolean validEdgeDistance(double r_lat_deg,
                          double r_lon_deg,
                          double a_lat_deg,
                          double a_lon_deg,
                          double b_lat_deg,
                          double b_lon_deg)

This method decides for case 1: if we should use distance(r to edge) where r=(lat,lon) or case 2: min(distance(r to a), distance(r to b)) where edge=(a to b). Note that due to rounding errors it cannot properly detect if it is case 1 or 90°.

 case 1 (including ):
   r
  .
 a-------b
 

 case 2:
 r
  .
    a-------b
 

Returns:

true for case 1 which is "on edge" or the special case of 90° to the edge

calcNormalizedEdgeDistance

double calcNormalizedEdgeDistance(double r_lat_deg,
                                  double r_lon_deg,
                                  double a_lat_deg,
                                  double a_lon_deg,
                                  double b_lat_deg,
                                  double b_lon_deg)

This method calculates the distance from r to edge (a, b) where the crossing point is c

Returns:

the distance in normalized meter

calcCrossingPointToEdge

GHPoint calcCrossingPointToEdge(double r_lat_deg,
                                double r_lon_deg,
                                double a_lat_deg,
                                double a_lon_deg,
                                double b_lat_deg,
                                double b_lon_deg)

Returns:

the crossing point c of the vertical line from r to line (a, b)

projectCoordinate

GHPoint projectCoordinate(double lat,
                          double lon,
                          double distanceInMeter,
                          double headingClockwiseFromNorth)

This methods creates a point (lat, lon in degrees) in a certain distance and direction from the specified point (lat, lon in degrees). The heading is measured clockwise from north in degrees. The distance is passed in meter.

isCrossBoundary

boolean isCrossBoundary(double lon1,
                        double lon2)