Question

我的主程序将创建一个DataSet对象，读入值并调用addValue实例方法，直到遇到负值。然后它将调用getAverage和getStandardDeviation方法并打印出返回结果。平均值是3.28 标准差为1.972815247 这是我的代码。我现在基本上被卡住了。

import java.util.Scanner;

public class DataSet {

    private double value;
    private double count;
    private double sum;
    private double sumofSquares;


    public void addValue(double value) {
        while (value >= 0) {
            count++;
            sum += value;
            sumofSquares += (value * value);

        }

    }

    public double getAverage() {
        return sum / count;

    }

    public double getStandardDeviation() {
        return Math.sqrt(((count * sumofSquares) - (sum * sum)) / (count * (count - 1)));

    }

    public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter Value");
    double value = sc.nextDouble();
    DataSet j1 = new DataSet();
    j1.addValue(value);
    System.out.println("The average of the value " + j1.getAverage());
    System.out.println("The Standard Deviation of the value" + j1.getStandardDeviation());

    }
}

Answer 1

这段代码似乎有很多问题。首先，您的输入代码不在while循环中，因此您不会获取任何新值。其次，你的addValue函数在输入正值时调用一个无限循环，因为while循环将继续运行并添加到你的DataSet成员。

我已经重构了您的代码以使其更有意义，请询问您是否对任何特定领域有任何疑问。

import java.util.Scanner;

public class DataSet {

private double value;
private double count;
private double sum;
private double sumofSquares;


public int addValue(double value) {
    if(value >= 0) {
        count++;
        sum += value;
        sumofSquares += (value * value);
        return 0;
    }else{
        System.out.println("The average of the value " + this.getAverage());
        System.out.println("The Standard Deviation of the value " + this.getStandardDeviation());
        return -1;
    }
}

public double getAverage() {
    return sum / count;

}

public double getStandardDeviation() {
    return Math.sqrt(((count * sumofSquares) - (sum * sum)) / (count * (count - 1)));

}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter Values");

    double value = 0;
    DataSet j1 = new DataSet();

    while(true){
        value = sc.nextDouble(); 

        if(j1.addValue(value) == 0){
            //continue
        }else{
            return;
        }
    }
}

}

具有浮点的数据集

1 个答案: