C編程：從文本文件中逐行讀取（雙精度）數字到2D數組

Question

我有一個用excel創建的文本文件，其中包含尺寸為36x35的表格。 值是雙數（例如2.58），文本文件如下所示：

1.25  2.31 ...
4.28  2.56 ...
3.27  ...
...   ...

我知道表的尺寸（arr_row，arr_column），因此聲明一個動態2D數組：

double **MUDG_table;

//dynamic allocate array of MUDG_table (1st Dimension)
MUDG_table = calloc(arr_row,sizeof(int *));

//check if the memory has been allocated correctly
if (MUDG_table==NULL) 
{
    printf("Error allocating memory!\n"); //print an error message
    return 1; //return with failure
}

for (cv02=0;cv02<arr_row;cv02++)
{
    //dynamic allocate array of MUDG_table (2nd Dimension)
    MUDG_table[cv02] = calloc(arr_column, sizeof(int));

    //check if the memory has been allocated correctly
    if (MUDG_table[cv02]==NULL) 
    {
        printf("Error allocating memory!\n"); //print an error message
        return 1; //return with failure
    }
}

到現在為止還挺好。 然后，我嘗試從文本文件中讀取值，並將它們存儲到數組中以進行進一步處理：

//************************************************************************************************************//
//read the text file with the values of the gain and save it to the MUDG_table
//************************************************************************************************************//

gain_ptr = fopen("MUDG_text.txt", "r");

if (gain_ptr == NULL)
{
    printf("Error Reading File\n");
    return 1; //return with failure
}

for (row=0;row<arr_row;row++)
{
    for (column=0;column<arr_column;column++)
    {
        fscanf(gain_ptr, " %1f", &MUDG_table[row][column]);
    }
}

fclose(gain_ptr);

問題是我得到的值類似於5.26346e-315＃DEN任何想法我做錯了。 是因為我不使用EOF嗎？

Answer 1

好的，因此，在瀏覽了幾篇文章並感謝我在這里得到的答復之后，我更改了代碼，使接縫正常工作。

首先，數組應聲明為double：

//dynamic allocate array of MUDG_table (1st Dimension)
MUDG_table = calloc(arr_row,sizeof(double *));

//check if the memory has been allocated correctly
if (MUDG_table==NULL) 
{
    printf("Error allocating memory!\n"); //print an error message
    return 1; //return with failure
}

for (cv02=0;cv02<arr_row;cv02++)
{
    MUDG_table[cv02] = calloc(arr_column, sizeof(double));

    //check if the memory has been allocated correctly
    if (MUDG_table[cv02]==NULL) 
    {
        printf("Error allocating memory!\n"); //print an error message
        return 1; //return with failure
    }
}

主要問題是fscanf，我不知道為什么它不起作用。 所以我用fgets代替了它。 我在另一篇文章中找到了此代碼，並對其進行了修改以在這種情況下工作。

gain_ptr = fopen("MUDG_text.txt", "r");

if (gain_ptr == NULL)
{
    printf("Error Reading File\n");
    return 1; //return with failure
}

for (row=0;row<arr_row;row++)
{
    fgets(buffer, 1024, gain_ptr); //buffer is declared as char buffer[1024];

    tok = strtok(buffer, "\t");    // NULL means 'continue from last token'  
    //tok is declared as char *tok;
    //the numbers in my text file are seperated by tabs
    //so the tokens should be separated by \t

    column = 0;  //since fgets gets a whole line I had to separate the columns
    while (tok != NULL) 
    {
        test_var = atof(tok);  //test variable is declared as double
        //and it is used to hold temporarily the value of tok in double
        tok = strtok(NULL, "\t");    // NULL means 'continue from last token'

        MUDG_table[row][column] = test_var;
        column++;
    }
}   
fclose(gain_ptr);

也許這不是最好的解決方案，但至少它能起作用。