如何将具有浮点数的文本文件读取到C中的浮点数组

Question

我一直在尝试阅读以下文本文件：

0.000   1.800   3.240   4.374   5.249   5.905   6.377   7.696   6.887   6.974   6.974   6.904   6.778   6.609   6.406   6.177   5.930   5.670   5.403   5.133   4.863   4.596   4.333   5.077   3.829   4.589   3.360   3.140   2.931   2.732   2.543   2.365   2.198   2.040   1.891   1.752   1.622   1.500   1.387   1.281   1.182   1.091   2.006   0.927   0.853   0.786   0.723   0.665   0.611   0.561   0.515   0.473   0.434   0.398   0.365   0.335   0.307   0.281   0.257   0.236   0.216   1.197   0.180   0.165   0.151   0.138   0.126   0.115   0.105   0.096   0.088   0.080   0.073   0.067   0.061   1.055   0.051   0.046   0.042   0.038   0.035   0.032   0.029   0.026   0.024   0.022   0.020   0.018   0.017   0.015   0.014   0.012   0.011   0.010   0.009   0.009   0.008   0.007   1.006   0.006   0.005   0.005

该数字与文本文件中的格式相同。

我的代码如下

#include <stdio.h> 

#include <stdlib.h>

void main()

{

        FILE *file = fopen("Data.txt", "r");
        float integers[102];

        int i=0;
        int num;
        while(fscanf(file, "%f", &num) >0) {
            integers[i] = num;
            i++;
        }
        if( file == NULL )
         {
            printf("Error while opening the file.\n");

         }
        fclose(file);
        for(i = 0;i <102; i++){
        printf("integers[%d] = %f",i, integers[i]);
        }


}

printf的输出是，运行时所有整数元素均为零。 另外，在尝试调试时，我注意到编译器会跳过while循环。 我正在使用Code Composer Studios。

Answer 1

从我的头顶

    //int num;
    float num; // should be float isn't is
    while(fscanf(file, "%f", &num) >0) {

更多

int main() // int main instead of void
{
    /* All declarations at one place */
    FILE *file = NULL; 
    float integers[102], num ;
    int i = 0;
    /* Try Open and exit if there is problem */ 
    file = fopen("Data.txt", "r");
    if( file == NULL ) {
        printf("Error while opening the file.\n");
        return -1;
    }
    /* Read and store EOF is always better */
    while( fscanf(file, "%f", &num) != EOF ) {
        integers[i++] = num;
    }
    /* Done with File Close it */
    fclose(file);
    /* Final Prints */
    for( i = 0; i < 102; i++ ){
        printf("integers[%d] = %.02f\n",i, integers[i]);
    }
    /* All success at this point */
    return 0;
}

Answer 2

这种方法作为一个例子：

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

int main() {
  FILE * fp;
  float fval[102];
  int n, i;

  fp = fopen("foo.txt", "w+");
  if (fp == NULL) {
    printf("failed to open file\n");
    return 1;
  }

  fputs("0.000   1.800   3.240   4.374   5.249   5.905   6.377   7.696 ", fp);
  rewind(fp);

  n = 0;
  while (fscanf(fp, "%f", &fval[n++]) != EOF)
    ;

  /* n-1 float values were successfully read */
  for (i=0; i<n-1; i++)
    printf("fval[%d]=%f\n", i, fval[i]);

  fclose(fp);
  return 0;
}

我得到以下输出：

fval[0]=0.000000
fval[1]=1.800000
fval[2]=3.240000
fval[3]=4.374000
fval[4]=5.249000
fval[5]=5.905000
fval[6]=6.377000
fval[7]=7.696000

Answer 3

使用vector可以解决这个问题，请参见下面的程序。myValues是2D数组。

ifstream input（“ Data.txt”）; 向量myValues;

对于（float num; input >> num;）myValues.push_back（num）;

要么

ifstream input（“ my-file.txt”）; std :: vector myValues;

for（float f; input >> f;）myValues.push_back（f）;