2014-09-05 25 views
1

我想从两个文本文件中读取矩阵,将它存储到2个数组中,然后尝试将这两个矩阵相乘并将结果存储在数组中。 乘法结果即将000.从两个文本文件乘以两个矩阵给出输出为零

下面是我的代码

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

int main(int argc,char *argv[]) 
{ 
    FILE *fr1, *fr2, *fw; 
    char *line = malloc(1000); 
    int count = 0; 
    //To read a file use the fopen() function to open it 
    fr1 = fopen(argv[1], "r"); 
    //If the file fails to open the fopen() returns a NULL 
    if (fr1 == NULL) { 
     printf("Cannot open %s. Program terminated...",argv[1]); 
     exit(1); 
    } 

    // Similar to the above method read the second file 
    fr2 = fopen(argv[2], "r"); 
    if (fr2 == NULL) { 
     printf("Cannot open %s. Program terminated...",argv[2]); 
     exit(1); 
    } 

    double *data = (double*) malloc(1000*sizeof(double)); 
    if(data == NULL) 
    { 
     printf("Error in allocating memory"); 
     return EXIT_FAILURE; 
    } 
    // Read number of columns and number of rows of first matrix 
    getline(&line, &count, fr1); 
    int read = -1, cur = 0, columCount1 = 0; 
    while(sscanf(line+cur, "%lf%n", &data[columCount1], &read) == 1) 
    {cur+=read; columCount1++;} 

    int rowCount1 = 1; 
    while(getline(&line, &count, fr1) != -1) {rowCount1++;} 
    printf("%d\n",columCount1); 
    printf("%d\n",rowCount1); 

    // Read number of columns and number of rows of second matrix 
    getline(&line, &count, fr2); 
    read = -1,cur = 0; 
    int columCount2 = 0; 
    while(sscanf(line+cur, "%lf%n", &data[columCount2], &read) == 1) 
    {cur+=read; columCount2++;} 

    int rowCount2 = 1; 
    while(getline(&line, &count, fr2) != -1) {rowCount2++;} 
    printf("%d\n",columCount2); 
    printf("%d\n",rowCount2); 
    int i=0; 
    int j=0; 

    int **mat1 = (int **)malloc(rowCount1 * sizeof(int*)); 
    for(i = 0; i < rowCount1; i++) 
    mat1[i] = (int *)malloc(columCount1 * sizeof(int)); 

    fseek(fr1, 0, SEEK_SET); 

    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount1; j++) 
      fscanf(fr1,"%d",&mat1[i][j]); 
    } 

    i = 0; 
    j = 0; 

    printf("\n\n"); 
    //print matrix 1 
    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount1; j++) 
      printf("%d",mat1[i][j]); 

     printf("\n"); 
    } 

    i = 0; 
    j = 0; 
    int **mat2 = (int **)malloc(rowCount2 * sizeof(int*)); 
    for(i = 0; i < rowCount2; i++) 
     mat2[i] = (int *)malloc(columCount2 * sizeof(int)); 

    fseek(fr2, 0, SEEK_SET); 

    for(i=0; i<rowCount2; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      fscanf(fr2,"%d",&mat2[i][j]); 
    } 

    i = 0; 
    j = 0; 

    printf("\n\n"); 
    //print matrix 2 
    for(i=0; i<rowCount2; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      printf("%d",mat2[i][j]); 

     printf("\n"); 
    } 

    i = 0; 

    int **mat3 = (int **)malloc(rowCount1 * sizeof(int*)); 
    for(i = 0; i < rowCount1; i++) 
     mat3[i] = (int *)malloc(columCount2 * sizeof(int)); 
    i = 0; 
    j = 0; 
    int k = 0; 
    int sum = 0; 
    //multiplication of two matrices 
    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount2; j++) 
     { 
      sum=0; 
      for(k=0; k<rowCount2; k++) 
       sum+=mat1[i][k]*mat2[k][j]; 
     } 
     mat3[i][j] = sum; 
    } 

    i = 0; 
    j = 0; 


    //print multiplication result 
    printf("\n\nResult = \n\n"); 

    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      printf("%d",mat3[i][j]); 

     printf("\n"); 
    } 

    return 0; 
} 
+0

你很可能已经达到了档案结尾的时候你已经阅读足以知道行数在返回前释放分配的内存,所以'而( !feof(fr1))''不会做太多...尝试'fseek'回到文件的开头。 – SleuthEye 2014-09-05 22:58:37

+0

谢谢。使用fseek解决了这个问题,但现在我得到了将两个矩阵乘以000的结果。 – user3648814 2014-09-05 23:24:50

+2

我发现它看起来很糟糕,现在你已经取消了NetVipeC的良好编辑。也就是说,使用调试器应该可以让你发现矩阵乘法有什么问题(提示:当将'sum'分配给'mat3'时,'j'的值是多少?) – SleuthEye 2014-09-05 23:41:02

回答

1

1)矩阵乘法之前检查如果矩阵1中的列数是相同的行中的矩阵编号为2

//Check if number of col in mat1 is same as number of rows in mat2 
if(columCount1 != rowCount2) 
{ 
    puts("The number of columns in Matrix 1 is not same as the number of rows in Matrix 2"); 
    exit(1); 
} 

2)代码的两个矩阵的乘法:

for(i=0;i<rowCount1;i++) 
{ 
    for(j=0;j<columCount2;j++) 
    { 
     mat3[i][j]=0; 
     for(k=0;k<columCount1;k++) 
     { 
      mat3[i][j] = mat3[i][j]+mat1[i][k] * mat2[k][j]; 
     } 
    } 
} 

3)main()

/* After printing the results free the memory */ 
for(i=0; i< rowCount1; i++) 
    free(mat1[i]); 
free(mat1); 

for(i=0; i< rowCount2; i++) 
    free(mat2[i]); 
free(mat2); 

for(i=0; i< rowCount1; i++) 
    free(mat3[i]); 
free(mat3); 

free(data);