2-Dimensional Dynamic Array

Hi,
I tried to get my program to count the number of rows in the input data file and then output back the same data with 7 columns and however many rows. It's giving me all zeros in the output file though, which isn't supposed to happens since the input file is just random numbers, e.g.:

123.45 111.23 33.45 66.345 43545.54 543.54 5435.43

Could someone take a look at the code?

Code:

---

        int j , i;
        int rows = 1;
        float num;
        int c;

        while ((c = fgetc(fp)) != EOF)
        {
                if (c == '\n')
                {
                rows++;
                printf("%d\n", rows);
                }
        }
       
        float **data;
        data = (float**) malloc(rows * sizeof(int));
        for (int i = 0; i < rows; i++)
        {data[i] = (float*)malloc(7*sizeof(int));
        }
       
        //declares array with 7 columns and number of rows in file
       
        for (j=0; j< rows; j++) //repeats for max number of columns
        {
                for (i=0; i< 7; i++)
                {
                        fscanf(fp, "%f", &num);
                       
                        data[j][i] = num;
                }
        }       
       
       
        for(j = 0; j < rows; j++) //repeats for max number of columns
        {
                for (i=0; i< 7; i++)
                {
                        num = data [j][i];
                       
                        fprintf(fp2, "%f ", num);
                       
                }
                fprintf(fp2, "\n");
        }

---

Thanks.

Code:

---

data = (float**) malloc(rows * sizeof(int));

---

What on earth is this supposed to do?


Quzah.

Oh sorry, those floats are meant to be integers, I was just trying some stuff and I forgot to change it back. Revised code:

Code:

---

int j , i;
        int rows = 1;
        float num;
        int c;

        while ((c = fgetc(fp)) != EOF)
        {
                if (c == '\n')
                {
                rows++;
                printf("%d\n", rows);
                }
        }
       
        int **data;
        data = (int**) malloc(rows * sizeof(int));
        for (int i = 0; i < rows; i++)
        {data[i] = (int*)malloc(7*sizeof(int));
        }
       
        //declares array with 7 columns and number of rows in file
       
        for (j=0; j< rows; j++) //repeats for max number of columns
        {
                for (i=0; i< 7; i++)
                {
                        fscanf(fp, "%f", &num);
                       
                        data[j][i] = num;
                }
        }       
       
       
        for(j = 0; j < rows; j++) //repeats for max number of columns
        {
                for (i=0; i< 7; i++)
                {
                        num = data [j][i];
                       
                        fprintf(fp2, "%f ", num);
                       
                }
                fprintf(fp2, "\n");
        }

---

The data you want to read in looks like floating point to me. So you want to allocate floats, not ints.

Quote:

---

Originally Posted by juice_box

Code:

---

...
        while ((c = fgetc(fp)) != EOF)
        {
...       
        for (j=0; j< rows; j++) //repeats for max number of columns
        {
                for (i=0; i< 7; i++)
                {
                        fscanf(fp, "%f", &num);
                       
                        data[j][i] = num;
                }
        }

---

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Ignoring your problems with malloc(), you're reading to the end of the file, and then reading some more.