Question

当我尝试使用方法gravity2时，我得到零输出，我仍然不完全了解分离方法如何帮助，因为我不熟悉不同方法的规则。我如何调用该方法以使q[]打印？

public class Gravity
{

    public static double[] gravity(double[] radius, double[] z, double[] radius1)
    {
        for (int index = 0; index < radius.length; index++)
        {

            z[index] = radius[index] * radius1[index];

        }

        return z;
    }

    public static double[] gravity2(double[] q, double[] masses, double[] z)
    {
        for (int index = 0; index < masses.length; index++)
        {
            q[index] = (z[index] * 6.67E-11) / masses[index];
        }
        return z;

    }

    public static void printResults(String[] names, double[] z, String[] m, double[] q) throws IOException
    {
        System.out.println(" Plantetary Data");
        System.out.println("=====================================");
        System.out.println("Planet    Diameter    Mass    Gravity");
        for (int index = 0; index < names.length; index++)
        {
            System.out.printf("%1s  ", names[index]);
            System.out.printf("%7.1f", z[index]);
            System.out.printf("%10s", m[index]);
            System.out.printf("%6.1f", q[index]);
            System.out.printf("%n");
        }
    }

    public static void main(String[] args) throws IOException
    {
        // Initialize variables
        String[] names =
        {
            "Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune", "Pluto"
        };
        double[] radius =
        {
            2439.7, 6051.9, 6378, 3402.5, 71492, 60270, 25562, 24774, 1195
        };
        double[] masses =
        {
            3.3022 * Math.pow(10, 23), 4.8685 * Math.pow(10, 24), 5.9736 * Math.pow(10, 24), 6.4185 * Math.pow(10, 23), 1.8986 * Math.pow(10, 27), 5.6846 * Math.pow(10, 26), 8.6810 * Math.pow(10, 25), 1.0243 * Math.pow(10, 26), 1.312 * Math.pow(10, 22)
        };
        8.68E+25

    , 1.02E+26, 1.27E+22}; // See IMACS double lesson for big E notation
        double[] radius1 =
    {
        2439.7, 6051.9, 6378, 3402.5, 71492, 60270, 25562, 24774, 1195
    };
    double z[] = new double[10];
    double q[] = new double[10];
    String m[] =
    {
        "3.30E+23", "4.87E+24", "5.97E+24", "6.42E+23", "1.90E+27", " 5.68E+26", " 8.68E+25", "1.02E+26", " 1.27E+22"
    };
    // Processing
    double gravities1[] = gravity(radius, z, radius1);
    double gravities2[] = gravity2(q, masses, z);
        // Output

    printResults(names, z, m, q);

    printToFile(gravities1);

    printToFile(gravities2);
}

Answer 1

问题是q中的值非常小，大小为10e-27，因此当您尝试使用如此少的小数位数进行打印时，它会显示0.更改为如下所示：< / p>

System.out.printf("%g  ", q[index]);

你会得到：

 Plantetary Data
=====================================
Planet    Diameter    Mass    Gravity
Mercury  5952136.1    3.30E+23  1.20225e-27  
Venus  36625493.6    4.87E+24  5.01781e-28  
Earth  40678884.0    5.97E+24  4.54212e-28  
Mars  11577006.3    6.42E+23  1.20306e-27  
Jupiter  5111106064.0    1.90E+27  1.79559e-28  
Saturn  3632472900.0    5.68E+26  4.26215e-28  
Uranus  653415844.0    8.68E+25  5.02049e-28  
Neptune  613751076.0    1.02E+26  3.99660e-28  
Pluto  1428025.0    1.27E+22  7.25985e-27

我的输出结果为零

1 个答案: