/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 org.apache.lucene.spatial.geometry.shape;
/**
* Imported from mq java client. No changes made.
*
* <p><font color="red"><b>NOTE:</b> This API is still in
* flux and might change in incompatible ways in the next
* release.</font>
*
* @deprecated This has been replaced with more accurate
* math in {@link LLRect}. This class will be removed in a future release.
*/
@Deprecated
public class DistanceApproximation
{
private double m_testLat;
private double m_testLng;
private double m_mpd;
private static final double m_milesPerLngDeg[]={
69.170976f, 69.160441f, 69.128838f, 69.076177f, 69.002475f,
68.907753f, 68.792041f, 68.655373f, 68.497792f, 68.319345f,
68.120088f, 67.900079f, 67.659387f, 67.398085f, 67.116253f,
66.813976f, 66.491346f, 66.148462f, 65.785428f, 65.402355f,
64.999359f, 64.576564f, 64.134098f, 63.672096f, 63.190698f,
62.690052f, 62.170310f, 61.631630f, 61.074176f, 60.498118f,
59.903632f, 59.290899f, 58.660106f, 58.011443f, 57.345111f,
56.661310f, 55.960250f, 55.242144f, 54.507211f, 53.755675f,
52.987764f, 52.203713f, 51.403761f, 50.588151f, 49.757131f,
48.910956f, 48.049882f, 47.174172f, 46.284093f, 45.379915f,
44.461915f, 43.530372f, 42.585570f, 41.627796f, 40.657342f,
39.674504f, 38.679582f, 37.672877f, 36.654698f, 35.625354f,
34.585159f, 33.534429f, 32.473485f, 31.402650f, 30.322249f,
29.232613f, 28.134073f, 27.026963f, 25.911621f, 24.788387f,
23.657602f, 22.519612f, 21.374762f, 20.223401f, 19.065881f,
17.902554f, 16.733774f, 15.559897f, 14.381280f, 13.198283f,
12.011266f, 10.820591f, 9.626619f, 8.429716f, 7.230245f,
6.028572f, 4.825062f, 3.620083f, 2.414002f, 1.207185f,
1.000000f};
public static final double MILES_PER_LATITUDE = 69.170976f;
public static final double KILOMETERS_PER_MILE = 1.609347f;
public DistanceApproximation()
{
}
public void setTestPoint(double lat, double lng)
{
m_testLat = lat;
m_testLng = lng;
m_mpd = m_milesPerLngDeg[(int)(Math.abs(lat) + 0.5f)];
}
// Approximate arc distance between 2 lat,lng positions using miles per
// latitude and longitude degree
public double getDistanceSq(double lat, double lng)
{
double latMiles = (lat - m_testLat) * MILES_PER_LATITUDE;
// Approximate longitude miles using the miles per degree assuming the
// middle latitude/longitude. This is less accurate at high (near
// polar) latitudes but no road network is present at the poles!
// If we ever have any roads crossing the international date we will
// have to worry about that case.
double lngMiles = (lng - m_testLng) * m_mpd;
// Find the squared distance by the Pythagorean theorem (without sqrt)
return (latMiles * latMiles + lngMiles * lngMiles);
}
// Approximate arc distance between a segment (with lat,lng endpoints) and
// the test position
public double getDistanceSq(double lat1, double lng1, double lat2, double lng2)
{
// Check if lat1,lng1 is closest point. Construct a vector from point1
// to point2 (v1) and another from point 1 to the test point (v2).
// If dot product is negative then point 1 is the closest point
double v1y = lat2 - lat1;
double v1x = lng2 - lng1;
double v2y = m_testLat - lat1;
double v2x = m_testLng - lng1;
double dot = v1x * v2x + v1y * v2y;
if (dot <= 0.0f)
return getDistanceSq(lat1, lng1);
// Get the component of vector v2 along v1. If component is greater
// than 1 then the endpoint is the closest point.
double c = dot / (v1x * v1x + v1y * v1y);
if (c >= 1.0f)
return getDistanceSq(lat2, lng2);
// Since we are working io lat,lng space we need to find the point
// along p1->p2 such that q->pt is perpendicular to p1->p2. We
// then find the distance squared between Q and pt.
return getDistanceSq((lat1 + v1y * c), (lng1 + v1x * c));
}
// Return the number of miles per degree of longitude
public static double getMilesPerLngDeg(double lat)
{
return (Math.abs(lat) <= 90.0) ? m_milesPerLngDeg[(int)(Math.abs(lat) + 0.5f)] : 69.170976f;
}
public static double getMilesPerLatDeg() {
return MILES_PER_LATITUDE;
}
}