如何编写求4×3维双精度数组平均值的方法

Question

我试图找到4×3维数组的平均值，但是当我运行代码时，我收到了异常错误。问题是如何对数组中的各个数字求和，这样我就可以通过除以其长度来求其平均值。

这是我的密码：

    double[][] numbers = {{1.1,2.2,1.3},{2.1,3.4,3.2},{5.4,6.5,3.7},{4.2,3.5,7.4}};
    double average = averagenum(numbers);
    System.out.println(average);
}

public static double averagenum(double[][] numbers) {
    double average = 0;
    double sum = 0;
    for(int i=0; i<numbers.length;i++){
        sum+= numbers[i][i+1];
        average = sum/numbers.length;
    }
    return average;
}

}

Answer 1

对于二维数组，必须遍历每个循环并对每个元素求和。因此，您可以看到循环在每个维度上迭代的次数为2次。我对每个数字求和，然后除以每个维度的乘积

我猜您正在寻找以下代码。

public class CalculateAvg
{
  public static void main (String[] args)
  {
    double[][] numbers = { { 1.1, 2.2, 1.3 }, { 2.1, 3.4, 3.2 }, { 5.4, 6.5, 3.7 }, { 4.2, 3.5, 7.4 } };
    double average = averagenum(numbers);
    System.out.println(average);

  }

  public static double averagenum (double[][] numbers)
  {
    double totalAverage = 0.0d;
    double totalSum = 0;

    for (int i = 0; i < numbers.length; i++)
    {
      for (int j = 0; j < numbers[0].length; j++)
      {
        totalSum += numbers[i][j];
      }
    }
    totalAverage = totalSum / (numbers.length*numbers[0].length);
    return totalAverage;
  }
}

Answer 2

谢谢你的评论，我终于明白了

public static void main(String[] args) {
        double[][] numbers = {{1.1,2.2,1.3},{2.1,3.4,3.2},{5.4,6.5,3.7},{4.2,3.5,7.4}};
        System.out.println("\tAverage:"+averagenum(numbers)+"\n");
        printer(numbers);
    }

    public static double averagenum(double[][] numbers) {
        double average = 0;
        double sum = 0;
        int num = numbers.length * numbers[0].length;
        for(int i=0; i<numbers.length;i++){
            for(int j=0; j<numbers[0].length; j++){
                sum+= numbers[i][j];    
            }  
        }
        average = sum/num ;

        return average;
    }
    public static void printer(double[][] GenArray) {

        System.out.println("\tContent in Array:"+Arrays.deepToString(GenArray));
    }
}