如何打印两个城市之间的距离，给定他们的纬度和经度坐标？

Question

我的代码是这样开始的：

    public static void main(String[] args) {

//Intro 
    System.out.print("This program calculates the distance between two cities,     given their respective latitude and longitude points.");
    System.out.println();

//Get values for Latitude and Longitude
Scanner console = new Scanner(System.in);
    double lat1 = getCoordinates(" latitude 1: ", console); // Input lat1
    double long1 = getCoordinates(" longitude 1: ", console); // Input long1
    double lat2 = getCoordinates(" latitude 2: ", console); // Input lat2
    double long2 = getCoordinates(" longitude 2: ", console); // Input long2

public static double getCoordinates(String message, Scanner scan)
    {   
    System.out.print("Please enter" + message);
    int degrees = scan.nextInt();
    int minutes = scan.nextInt();
    return Math.toRadians(degrees + (minutes / 60.0));
    }

//Calculate Distance
public static double finalAnswer(double lat1, double long1, double lat2, double long2) {
double radiusOfEarth = 6372.795; //radius of Earth in km
double distance = Math.acos(Math.sin(lat1)*Math.sin(lat2) + 
                  Math.cos(lat1)*Math.cos(lat2) *
                  Math.cos(long2-long1)) * radiusOfEarth;

return distance;
System.out.print("The distance between the two cities is approximately " + distance + "km");

}
}

我需要能够输入每个纬度和经度点的度和分钟（度，分钟）。然而，当我试图在代码的最后一行打印“距离”时，出现了编译错误。此外，Eclipse告诉我没有使用lat1、long1、lat2和long2（“获取纬度和经度值”部分）？有人能帮我打印距离吗？非常感谢。

Answer 1

以下代码可以计算给定经度和纬度的位置之间的距离。它使用哈弗森公式

import java.util.Scanner;
class haversine {
        double long1;
        double lat1;
        double long2;
        double lat2;
        haversine (Double long1, Double lat1, Double long2, Double lat2) {
                this.long1 = long1;
                this.lat1 = lat1;
                this.long2 = long2;
                this.lat2 = lat2;
        }
        double execute() {
                return Math.pow(Math.sin((lat2 - lat1)/2) ,2) + Math.cos(long1) * Math.cos(long2) * Math.pow(Math.sin((long2 - long1)/2) ,2);
        }
        double disCalc (Double exe) {
                Double radius_of_earth = 6378.1;
                return 2 * radius_of_earth * Math.asin(Math.pow(exe, 2));
        }

}
class test28 {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);
                System.out.println("longitude and latitude of home : ");
                double long1 = scan.nextDouble();
                double lat1 = scan.nextDouble();
                System.out.println("longitude and latitude of travel destination : ");
                double long2 = scan.nextDouble();
                double lat2 = scan.nextDouble();
                haversine obj = new haversine(long1, lat1, long2, lat2);
                double exe = obj.execute();
                double distance = obj.disCalc(exe);
                System.out.println("The Distance is : " + distance);
                scan.close();


        }
}

Answer 2

你能通过这些链接找出两个纬度和经度之间的距离吗

http://www.codeproject.com/Articles/12269/Distance-between-locations-using-latitude-and-long

或者还有另一个想法，你可以尝试使用谷歌地图API通过纬度和经度找出两个城市之间的距离

希望这有帮助

Answer 3

在代码中：

..
return distance;
System.out.print("The distance between the two cities is approximately " 
    + distance + "km");
..

将此更改为：

..
System.out.print("The distance between the two cities is approximately " 
    + distance + "km");
return distance;
..

下面是一个用Javascript实现的哈弗森公式，用于计算距离。（应易于翻译为Java。）

计算“大圆”距离的公式：

坐标为{lat1，lon1}和{lat2，lon2}的两点之间的大圆距离d由下式给出：

d=acos（sin（lat1）*sin（lat2）cos（lat1）*cos（lat2）*cos（lon1-lon2））

一个数学上等效的公式是，短距离舍入误差较小：

d=2*asin（sqrt（（sin（（lat1-lat2）/2））^2 cos（lat1）cos（lat2）（sin（（lon1-lon2）/2））^2）