用Java中的Haversine公式计算大圆周距离时的不正确输出

Question

我试图用Java中的Haversine公式计算大圆周的公里数，如下所示

/* Program to demonstrate the Floating-point numbers and the Math library.
 * The great-circle distance is the length of the shortest path between two points (x1,y1) and (x2,y2) on the surface of a sphere, where the path is constrained to be along the surface.*/
public class GreatCircle 
{
    public static void main(String[] args) 
    {
        double r = 6371.0; // Equatorial radius of the Earth
        double x1 = Math.toRadians(Double.parseDouble(args[0]));
        double y1 = Math.toRadians(Double.parseDouble(args[1]));
        double x2 = Math.toRadians(Double.parseDouble(args[2]));
        double y2 = Math.toRadians(Double.parseDouble(args[3]));

        // Compute using Haversine formula
        double distance = 2 * r * Math.asin(Math.sqrt(Math.pow(Math.sin((x2 - x1) / 2),2 + Math.cos(x2) * Math.pow(Math.sin((y2 - y1) / 2),2)));

        // Output the distance
        System.out.println(distance + " kilometers ");
    }
}

我正在运行输入java GreatCircle 60.0 15.0 120.0 105.0。预期的输出是4604.53989281927 kilometers，但我得到了13406.238676180266 kilometers。有人能指出我哪里出了问题吗？

Answer 1

该公式的实施不正确。在做了以下修正之后，它就起了作用。在公式中，我们取整个表达式的弧罪恶。

        // Compute using Haversine formula
        double distance = 2 * r * Math.asin(Math.sqrt(Math.pow(Math.sin((x2 - x1) / 2),2 + Math.cos(x2) * Math.pow(Math.sin((y2 - y1) / 2),2)));

        // Output the distance
        System.out.println(distance + " kilometers ");
    }
}

Answer 2

您忘记计算Math.cos(x1) * Math.cos(x2)**，了，这就是为什么您得到了不同的结果。

// Compute using Haversine formula<br>
double distance = 2 * r * Math.asin(Math.sqrt((Math.pow(Math.sin((x2 - x1) / 2),2) + Math.cos(x1) * Math.cos(x2) * Math.pow(Math.sin((y2 - y1) / 2),2))));```

Answer 3

double distance = 2 * r * Math.asin(Math.sqrt(Math.pow(Math.sin((x2 - x1) / 2),2)
            + Math.cos(x2) * Math.cos(x1) * Math.pow(Math.sin((y2 - y1) / 2),2)));