在C中将strtof值分配给2D数组

Question

I'm trying to parse a CSV file into a 2D array in C. I want to make a matrix wit the structure :

typedef struct {
    int row;
    int col;
    float **arr;
    int numElements;
} Matrix;

The function I'm using takes in a dynamically allocated 2D array of floats, and is returned. I'm reading the values in using fgets, tokenizing each value between commas using strtok and then converting the string returned using strtof.

First, I made the 2D arrays dynamically and then pass them to the function to be filled in with values,

RMatrix->arr = make2DArray(RMatrix->row, RMatrix->col);
    VMatrix->arr = make2DArray(VMatrix->row, VMatrix->col);

    printf("RMatrix->arr : %p \n", RMatrix->arr);
    printf("VMatrix->arr : %p \n", VMatrix->arr);

    parseCSV(fpRMatrix, RMatrix->arr, RMatrix->row, RMatrix->col, &(RMatrix->numElements), INPUT_LENGTH);
    printf("RMatrix parsed\n");
    parseCSV(fpVMatrix, VMatrix->arr, VMatrix->row, VMatrix->col, &(VMatrix->numElements), INPUT_LENGTH);
    printf("VMatrix parsed\n");

Below are the functions :

void parseCSV(FILE *fp, float **output, int row, int col, int *numElements ,int inputLength)
{
    char *buffer;
    int rowArr = 0;

    printf("Output : %p \n", output);

    buffer = (char*) malloc(inputLength * sizeof(char));

    while(fgets(buffer, inputLength, fp)) {
        char *p =strtok(buffer,",");
        int colArr = 0;         
        float check = 0;

        while(p)
        {
            printf("p now : %s \n", p);
            check = strtof(p, (char**) NULL);
            printf("check now : %f \n", check);
            output[rowArr][colArr] = strtof(p, (char**) NULL);
            *numElements += 1;
            colArr++;
            p = strtok('\0',",");
            printf("output[%d][%d] : %f  ", rowArr, colArr, output[rowArr][colArr]);
        }
        printf("\n");
        rowArr++;
    }
    printf("numElements in the end : %d\n", *numElements);
    free(buffer);

}

float **make2DArray(int row, int col) 
{  
    float** arr;
    float* temp;

    arr = (float**)malloc(row * sizeof(float*));
    temp = (float*)malloc(row * col * sizeof(float));
    for (int i = 0; i < row; i++) {
        arr[i] = temp + (i * row);
    }

    return arr;

}

The output :

Name : RMatrix
NumElements : 0
Rows : 2
Cols : 4
Name : VMatrix
NumElements : 0
Rows : 2
Cols : 4
RMatrix->arr : 0x11684d0 
VMatrix->arr : 0x1168520 
Output : 0x11684d0 
p now : 1 
check now : 1.000000 
output[0][1] : 0.000000  p now : 2 
check now : 2.000000 
output[0][2] : 0.000000  p now : 3 
check now : 3.000000 
output[0][3] : 0.000000  p now : 4

check now : 4.000000 
output[0][4] : 0.000000  
p now : 5 
check now : 5.000000 
output[1][1] : 4.000000  p now : 6 
check now : 6.000000 
output[1][2] : 0.000000  p now : 7 
check now : 7.000000 
output[1][3] : 0.000000  p now : 8

check now : 8.000000 
output[1][4] : 0.000000  
numElements in the end : 8
RMatrix parsed
Output : 0x1168520 
p now : 1 
check now : 1.000000 
output[0][1] : 0.000000  p now : 2 
check now : 2.000000 
output[0][2] : 0.000000  p now : 3 
check now : 3.000000 
output[0][3] : 0.000000  p now : 4

check now : 4.000000 
output[0][4] : 0.000000  
p now : 5 
check now : 5.000000 
output[1][1] : 4.000000  p now : 6 
check now : 6.000000 
output[1][2] : 0.000000  p now : 7 
check now : 7.000000 
output[1][3] : 0.000000  p now : 8

check now : 8.000000 
output[1][4] : 0.000000  
numElements in the end : 8
VMatrix parsed

As you can see, the strtof call succeeded (reflected in p and check variable) but not the assignment into the array.

I've only been using C for a month and I'm fascinated by it. However, it's obvious I need to learn more. I really appreciate your help :)

Answer 1

this

arr[i] = temp + (i * row);

should be

arr[i] = temp + (i * col);

since i = [0,row-1]