java - 带有静态方法的数组

Question

我正在尝试使用两种不同的静态方法来操作两个数组

double dot(double[]a, double[]b)

double[][] multiply(double[][]a, double[][]b) .

我似乎无法弄清楚如何使用静态方法将两个数组相乘并将这些值输出给用户，但我相信我的点积方法很好。我知道我的乘法方法需要使用返回方法，但我不确定如何正确表示

这是我到目前为止所拥有的:

public class LibMatrix {

    public static void main(String[] args) {

        double[] a = { 8, 5, 6, 3, 2, 1 };
        double[] b = { 9, 8, 4, 1, 4, 7 };
    }

    public static double dot(double[] a, double[] b) {
        double sum = 0.0;
        for (int i = 0; i < a.length; i++)
            sum += a[i] * b[i];
        return sum;

    }

    public static double[][] multiply(double[][] a, double[][] b) {
        int n = 6;
        double[][] c = new double[n][n];
        for (int i = 0; i < n; i++)
            for (int j = 0; i < n; i++)
                c[i][j] = a[i][j] * b[i][j];
        return a;

    }
}

Answer 1

以下是一些更正:

public class LibMatrixTests
{
   static class LibMatrix {
      public static double dot(double[] a, double[] b) {
         double sum = 0.0;
         for (int i = 0; i < a.length; i++)
            sum += a[i] * b[i];
         return sum;
      }
      public static double[][] mul( double[][] a, double[][] b ) {
         double[][] c = new double[a.length][a[0].length];
         for (int i = 0; i < a.length; i++)
            for (int j = 0; j < a[i].length; j++)
               c[i][j] = a[i][j] * b[i][j];
         return a;
      }
   }

   public static void main( String[] args ) {
      double[]   a = { 8, 5, 6, 3, 2, 1 };
      double[]   b = { 9, 8, 4, 1, 4, 7 };
      double[][] c = { a, b };
      double[][] d = { b, a };
      double     e = LibMatrix.dot( a, b );
      double[][] f = LibMatrix.mul( c, d );
      System.out.println( e );
      for( double[] g : f ) {
         for( double h : g ) {
            System.out.print( h + ", " );
         }
         System.out.println();
      }
   }
}

输出:

154.0
8.0, 5.0, 6.0, 3.0, 2.0, 1.0, 
9.0, 8.0, 4.0, 1.0, 4.0, 7.0,