Java - 计算距离和到原点的距离 - 问题

Question

我忘记了学校里的旧数学。我制作了一个 java 类来计算 x,y,z 和 origo 之间的距离。

但是在某个地方转错了方向，出不来……计算没有给出正确的值。你能帮我看看我做错了什么吗？这是距离计算错误。

import java.io.PrintWriter;
import java.util.Scanner;    

public class U3point {
    public static void main(String[] args) {    

        System.out.println("Values for x,y,z ");    

        Scanner in = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out, true);    

        double x;
        double y;
        double z;    

        String[] koordinater = null;
        String rad = in.nextLine();    

        System.out.println("toString: ");    

        while (!rad.equals("")) {
            koordinater = rad.split("\\s");
            x = Double.parseDouble(koordinater[0]);
            y = Double.parseDouble(koordinater[1]);
            z = Double.parseDouble(koordinater[2]);    

            Point p = new Point(x, y, z);    

            out.println(p);    

            //call method for origo
            double d = p.getDistanceToOrigo();
            System.out.println("Distance to Origo: " + d);    

            //  call method for distance
            double d2 = p.getDistanceTo(x, y, z);
            System.out.println("Distance: " + d2);    

            System.out.println("Exit program with enter or new values");
            rad = in.nextLine();    

        }
    }
}    

class Point {    

    private double x;
    private double y;
    private double z;    

    public Point(double x1, double y1, double z1) {
        x = x1;
        y = y1;
        z = z1;
    }    

    public void setX(double x1) {
        x = x1;
    }    

    public void setY(double y1) {
        y = y1;
    }    

    public void setZ(double z1) {
        z = z1;
    }    

    public double[] getCoordinates() {
        return new double[] { x, y, z };
    }    

    public double getDistanceTo(double x2, double y2, double z2) {
        return (Math.sqrt(((x - x2) * (x - x2) + (y - y2) * (y - y2) + (z - z2) * (z - z2))));
    }    

    public double getDistanceToOrigo()    

    {
        return (Math.sqrt(((x) * (x) + (y) * (y) + (z) * (z))));
    }    

    public String toString() {
        return " x: =" + x + " y:=" + y + " z:=" + z;    

    }
}

Answer 1

您计算到同一点的距离的问题，这里有一个适合您的方法:

import java.io.PrintWriter;
import java.util.Scanner;    

public class U3point {
    public static void main(String[] args) {    

        PrintWriter out = new PrintWriter(System.out, true);    

        Point p1 = generatePoint();
        Point p2 = generatePoint();    

        out.println(p1);
        out.println(p2);    

        // call method for origo double
        double d = p1.getDistanceToOrigo();
        System.out.println("Distance to Origo: " + d);    

        // call method for distance
        double d2 = p1.getDistanceTo(p2.getX(), p2.getY(), p2.getZ());
        System.out.println("Distance: " + d2);    

        System.out.println("The end!!");
    }    

    public static Point generatePoint() {
        System.out.println("Values for x,y,z ");
        String[] koordinater = null;
        Scanner in = new Scanner(System.in);
        String rad = in.nextLine();    

        Point p = null;    

        koordinater = rad.split("\\s");    

        double x = Double.parseDouble(koordinater[0]);
        double y = Double.parseDouble(koordinater[1]);
        double z = Double.parseDouble(koordinater[2]);    

        p = new Point(x, y, z);    

        return p;    

    }    

}    

class Point {    

    private double x;
    private double y;
    private double z;    

    public Point(double x1, double y1, double z1) {
        x = x1;
        y = y1;
        z = z1;
    }    

    public void setX(double x1) {
        x = x1;
    }    

    public void setY(double y1) {
        y = y1;
    }    

    public void setZ(double z1) {
        z = z1;
    }    

    public double getX() {
        return x;
    }    

    public double getY() {
        return y;
    }    

    public double getZ() {
        return z;
    }    

    public double[] getCoordinates() {
        return new double[] { x, y, z };
    }    

    public double getDistanceTo(double x2, double y2, double z2) {
        return (Math.sqrt(((x - x2) * (x - x2) + (y - y2) * (y - y2) + (z - z2) * (z - z2))));
    }    

    public double getDistanceToOrigo() {
        return (Math.sqrt(((x) * (x) + (y) * (y) + (z) * (z))));
    }    

    public String toString() {
        return " x: =" + x + " y:=" + y + " z:=" + z;    

    }
}

输出:

Values for x,y,z 
1 2 3
Values for x,y,z 
4 5 6
 x: =1.0 y:=2.0 z:=3.0
 x: =4.0 y:=5.0 z:=6.0
Distance to Origo: 3.7416573867739413
Distance: 5.196152422706632
The end!!