com.graphhopper.util.DistancePlaneProjection Maven / Gradle / Ivy
Show all versions of graphhopper-core Show documentation
/*
* Licensed to GraphHopper GmbH under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*
* GraphHopper GmbH licenses this file to you under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.graphhopper.util;
import static java.lang.Math.*;
/**
* 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
*/
public class DistancePlaneProjection extends DistanceCalcEarth {
public static final DistancePlaneProjection DIST_PLANE = new DistancePlaneProjection();
@Override
public double calcDist(double fromLat, double fromLon, double toLat, double toLon) {
double normedDist = calcNormalizedDist(fromLat, fromLon, toLat, toLon);
return R * sqrt(normedDist);
}
@Override
public double calcDist3D(double fromLat, double fromLon, double fromHeight,
double toLat, double toLon, double toHeight) {
double dEleNorm = hasElevationDiff(fromHeight, toHeight) ? calcNormalizedDist(toHeight - fromHeight) : 0;
double normedDist = calcNormalizedDist(fromLat, fromLon, toLat, toLon);
return R * sqrt(normedDist + dEleNorm);
}
@Override
public double calcDenormalizedDist(double normedDist) {
return R * sqrt(normedDist);
}
@Override
public double calcNormalizedDist(double dist) {
double tmp = dist / R;
return tmp * tmp;
}
@Override
public double calcNormalizedDist(double fromLat, double fromLon, double toLat, double toLon) {
double dLat = toRadians(toLat - fromLat);
double dLon = toRadians(toLon - fromLon);
double left = cos(toRadians((fromLat + toLat) / 2)) * dLon;
return dLat * dLat + left * left;
}
@Override
public String toString() {
return "PLANE_PROJ";
}
}