请为我提供用java开发的轨迹纠偏算法代码
时间: 2023-10-10 21:14:01 浏览: 96
以下是一个用Java语言实现的轨迹纠偏算法示例:
```java
import java.util.ArrayList;
import java.util.List;
public class TrajectoryCorrect {
// 轨迹压缩算法中的阈值
private static final double THRESHOLD = 0.1;
// 轨迹纠偏算法中的阈值
private static final double CORRECTION_THRESHOLD = 0.1;
/**
* 轨迹压缩算法
*
* @param points 原始轨迹点集合
* @return 压缩后的轨迹点集合
*/
public static List<Point> compress(List<Point> points) {
List<Point> result = new ArrayList<Point>();
if (points == null || points.size() == 0) {
return result;
}
result.add(points.get(0));
int size = points.size();
double maxDistance = 0;
int index = 0;
for (int i = 1; i < size; i++) {
Point currentPoint = points.get(i);
Point lastPoint = points.get(index);
double distance = getDistance(currentPoint, lastPoint);
if (distance > maxDistance) {
maxDistance = distance;
result.add(currentPoint);
index = i;
}
}
return result;
}
/**
* 轨迹纠偏算法
*
* @param points 原始轨迹点集合
* @return 纠偏后的轨迹点集合
*/
public static List<Point> correct(List<Point> points) {
List<Point> result = new ArrayList<Point>();
if (points == null || points.size() == 0) {
return result;
}
result.add(points.get(0));
int size = points.size();
int index = 0;
for (int i = 1; i < size - 1; i++) {
Point currentPoint = points.get(i);
Point lastPoint = points.get(index);
Point nextPoint = points.get(i + 1);
double distance = getDistanceToSegment(currentPoint, lastPoint, nextPoint);
if (distance > CORRECTION_THRESHOLD) {
result.add(currentPoint);
index = i;
}
}
result.add(points.get(size - 1));
return result;
}
/**
* 获取两个轨迹点之间的距离
*
* @param point1 轨迹点1
* @param point2 轨迹点2
* @return 距离
*/
private static double getDistance(Point point1, Point point2) {
double lat1 = point1.getLat();
double lng1 = point1.getLng();
double lat2 = point2.getLat();
double lng2 = point2.getLng();
double radLat1 = Math.toRadians(lat1);
double radLat2 = Math.toRadians(lat2);
double a = radLat1 - radLat2;
double b = Math.toRadians(lng1) - Math.toRadians(lng2);
double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) +
Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
s = s * 6378.137;
s = Math.round(s * 10000) / 10000;
return s;
}
/**
* 获取轨迹点到线段的距离
*
* @param point 轨迹点
* @param line1 线段起点
* @param line2 线段终点
* @return 距离
*/
private static double getDistanceToSegment(Point point, Point line1, Point line2) {
double lat1 = line1.getLat();
double lng1 = line1.getLng();
double lat2 = line2.getLat();
double lng2 = line2.getLng();
double lat = point.getLat();
double lng = point.getLng();
double a = lat2 - lat1;
double b = lng2 - lng1;
double c = lat - lat1;
double d = lng - lng1;
double dot = a * b + c * d;
double len_sq = a * a + b * b;
double param = -1;
if (len_sq != 0) {
param = dot / len_sq;
}
double xx, yy;
if (param < 0) {
xx = lat1;
yy = lng1;
} else if (param > 1) {
xx = lat2;
yy = lng2;
} else {
xx = lat1 + param * a;
yy = lng1 + param * b;
}
double dx = lat - xx;
double dy = lng - yy;
return Math.sqrt(dx * dx + dy * dy);
}
}
```
其中,`Point`类表示一个轨迹点,包含经度和纬度信息。`compress`方法实现了轨迹压缩算法,`correct`方法实现了轨迹纠偏算法,`getDistance`方法用于计算两个轨迹点之间的距离,`getDistanceToSegment`方法用于计算轨迹点到线段的距离。您可以根据自己的需求对代码进行修改和优化。
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