c 语言 计算信源熵

#include<stdio.h>
#include<math.h>
void main()
{
   int i;
    float x[4],h;
    FILE *fp,*fp1;
    if((fp=fopen("shuju.txt","r"))==NULL)
    {
     printf("不能打开文件:\n");
     exit(0);
    }
    if((fp1=fopen("jieguo.txt","w"))==NULL)
    {
    printf("不能打开文件:\n");
    exit(0);
    }
    for(i=0;i<4;i++)
    {
     fscanf(fp,"%f",&x[i]);
     printf( "x[%d]=%f",i,x[i]);
    }
    for(i=0;i<4;i++)
    {
    h+=(-x[i]*log(x[i])/log(2));
    }

    fprintf(fp1,"信源熵=%f\n",h);
    printf("信源熵=%f\n",h);
    fclose (fp);