两个矩阵乘法与点乘

图像中的计算往往是矩阵之间的运算，所以矩阵乘法具有重要的意义。

矩阵乘法

C代码

#include<stdio.h>
#include<stdlib.h>

int main() {
  int arr1[3][4] = { 0 };
  int arr2[4][3] = { 0 };
  int arr3[3][3] = { 0 };
  printf("输入第一个矩阵\n");
  for (int  i = 0; i <3; i++)
  {
    printf("输入第%d行：",i+1);
    for (int  j = 0; j < 4; j++)
    {
      scanf_s("%d", &arr1[i][j]);
    }
    printf("\n");
  }
  printf("输入第二个矩阵\n");
  for (int i = 0; i < 4; i++)
  {
    printf("输入第%d行：", i + 1);
    for (int j = 0; j < 3; j++)
    {
      scanf_s("%d", &arr2[i][j]);
    }
    printf("\n");
  }
  for (int i = 0; i < 3; i++)
  {
    for (int j = 0; j < 3; j++)
    { 
      int sum = 0;
      for (int k = 0; k < 4; k++)
      {
        sum = sum + arr1[i][k] * arr2[k][j];
      }
      arr3[i][j] = sum;
    }

  }
  printf("矩阵相乘为：\n");
  for (int i = 0; i < 3; i++)
  {
    for (int  j = 0; j < 3; j++)
    {
      printf("%4d",arr3[i][j]);
    }
    printf("\n");
  }
}

矩阵的点乘：对应元素相乘

代码

#include<stdio.h>
#include<stdlib.h>
#define row 3
#define col 4
int main() {
  int arr1[row][col] = { 0 };
  int arr2[row][col] = { 0 };
  int arr3[row][col] = { 0 };
  printf("输入第一个矩阵\n");
  for (int  i = 0; i < row; i++)
  {
    printf("输入第%d行：",i+1);
    for (int  j = 0; j < col; j++)
    {
      scanf_s("%d", &arr1[i][j]);
    }
    printf("\n");
  }
  printf("第二个矩阵为\n");
  for (int  i = 0; i < row; i++)
  {
    printf("输入第%d行：", i + 1);
    for (int j = 0; j < col; j++)
    {
      scanf_s("%d", &arr2[i][j]);
    }
    printf("\n");
  }
  printf("矩阵点乘的结果为：\n");
  for (int i = 0; i < row; i++)
  {
    for (int j = 0; j < col; j++)
    {
      printf("%4d", arr2[i][j]*arr1[i][j]);
    }
    printf("\n");
  }
  return 0;
}