/*
* Copyright 2010, NTT DOCOMO,INC.
*
* Licensed 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.
*/
/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed 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.
*
* distanceBetween���\�b�h�ɂė��p
*/
package jp.co.nttdocomo.star.util;
/**
* �ʒu��샆�[�e�B���e�B�[�N���X�ł��B<BR>
* 2�n�_�̈ܓx�o�x���狗���ƕ��ʊp���Z�o���܂��B<BR>
* @since utilib-1.0
*/
public class LocationUtils {
/**
* �C���X�^���X�����h�~�B
*/
private LocationUtils() {
// �����Ȃ�
}
/**
* 2�_�Ԃ̋����ƁA���̍ŒZ���[�g�̍ŏ��ƍŌ�̕��ʂ��v�Z���܂��B<BR>
* 2�_�Ԃ̋����ɂ��ẮA�������Z������Ԃ��܂��B�P�ʂ̓��[�g���ł��B<BR>
* �����ƕ��ʂ́AWGS84�ȉ~�̂�p���Čv�Z���܂��B<BR>
* @param startLatitude ���Z����t�f�[�^
* @param startLongitude ���Z������
* @param endLatitude ���Z����l
* @param endLongitude ���Z����l
* @param results �v�Z���ꂽ������result[0]�Ɋi�[����܂��B<BR>
* �����Aresults�z��̗v�f����2�ȏゾ�����ꍇ�A�ŏ��̕��ʊp��results[1]�Ɋi�[����܂��B<BR>
* �����Aresults�z��̗v�f����3�ȏゾ�����ꍇ�A�Ō�̕��ʊp��results[2]�Ɋi�[����܂��B<BR>
* @exception IllegalArgumentException
* �t�H�[�}�b�g�����s���ȏꍇ�ɔ������܂��B
*
*/
public static void distanceBetween(
double startLatitude,
double startLongitude,
double endLatitude,
double endLongitude,
float[] results) {
// Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
// using the "Inverse Formula" (section 4)
if (results == null || results.length < 1) {
throw new IllegalArgumentException(
"results is null or has length < 1");
}
int MAXITERS = 20;
// Convert lat/long to radians
startLatitude *= Math.PI / 180.0;
endLatitude *= Math.PI / 180.0;
startLongitude *= Math.PI / 180.0;
endLongitude *= Math.PI / 180.0;
double a = 6378137.0; // WGS84 major axis
double b = 6356752.3142; // WGS84 semi-major axis
double f = (a - b) / a;
double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);
double L = endLongitude - startLongitude;
double A = 0.0;
double U1 = MathUtils.atan((1.0 - f) * Math.tan(startLatitude));
double U2 = MathUtils.atan((1.0 - f) * Math.tan(endLatitude));
double cosU1 = Math.cos(U1);
double cosU2 = Math.cos(U2);
double sinU1 = Math.sin(U1);
double sinU2 = Math.sin(U2);
double cosU1cosU2 = cosU1 * cosU2;
double sinU1sinU2 = sinU1 * sinU2;
double sigma = 0.0;
double deltaSigma = 0.0;
double cosSqAlpha = 0.0;
double cos2SM = 0.0;
double cosSigma = 0.0;
double sinSigma = 0.0;
double cosLambda = 0.0;
double sinLambda = 0.0;
double lambda = L; // initial guess
for (int iter = 0; iter < MAXITERS; iter++) {
double lambdaOrig = lambda;
cosLambda = Math.cos(lambda);
sinLambda = Math.sin(lambda);
double t1 = cosU2 * sinLambda;
double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
double sinSqSigma = t1 * t1 + t2 * t2; // (14)
sinSigma = Math.sqrt(sinSqSigma);
cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
sigma = MathUtils.atan2(sinSigma, cosSigma); // (16)
double sinAlpha = (sinSigma == 0) ? 0.0 : cosU1cosU2 * sinLambda
/ sinSigma; // (17)
cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
cos2SM = (cosSqAlpha == 0) ? 0.0 : cosSigma - 2.0 * sinU1sinU2
/ cosSqAlpha; // (18)
double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
A = 1
+ (uSquared / 16384.0)
* // (3)
(4096.0 + uSquared
* (-768 + uSquared * (320.0 - 175.0 * uSquared)));
double B = (uSquared / 1024.0) * // (4)
(256.0 + uSquared
* (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
double C = (f / 16.0) * cosSqAlpha
* (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
double cos2SMSq = cos2SM * cos2SM;
deltaSigma = B
* sinSigma
* // (6)
(cos2SM + (B / 4.0)
* (cosSigma * (-1.0 + 2.0 * cos2SMSq) - (B / 6.0)
* cos2SM
* (-3.0 + 4.0
* sinSigma
* sinSigma)
* (-3.0 + 4.0 * cos2SMSq)));
lambda = L
+ (1.0 - C)
* f
* sinAlpha
* (sigma + C
* sinSigma
* (cos2SM + C * cosSigma
* (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)
double delta = (lambda - lambdaOrig) / lambda;
if (Math.abs(delta) < 1.0e-12) {
break;
}
}
float distance = (float) (b * A * (sigma - deltaSigma));
results[0] = distance;
if (results.length > 1) {
float initialBearing = (float) MathUtils.atan2(
cosU2 * sinLambda,
cosU1 * sinU2 - sinU1 * cosU2 * cosLambda);
initialBearing *= 180.0 / Math.PI;
results[1] = initialBearing;
if (results.length > 2) {
float finalBearing = (float) MathUtils.atan2(
cosU1 * sinLambda,
-sinU1 * cosU2 + cosU1 * sinU2 * cosLambda);
finalBearing *= 180.0 / Math.PI;
results[2] = finalBearing;
}
}
}
}