为什么我的结果有错。

#include <stdio.h>

#include <stdlib.h>

#include <string.h>



typedef char BYTE ;

typedef float DWORD;



int main()

{

    int i,j;

    FILE *fp1,*fp2;

    BYTE  *data1=(BYTE *)malloc(400*640*sizeof(BYTE));

    DWORD *data2=(DWORD *)malloc(400*640*sizeof(DWORD));

    

    if((fp1=fopen("sample","rb"))==NULL)

    {

         printf("can not is open file!");

         return 0;

    }

    if((fp2=fopen("sample2.txt","w"))==NULL)

    {

        printf("can not is open file!");

        return 0;

    }



    memset(data1,0,400*640*sizeof(BYTE));

    memset(data2,0,400*640*sizeof(DWORD));

    

    fread(data1,sizeof(char),400*640,fp1);

    for(i=0;i<400*640;i++);

    {

        data2[i]=(int)data1[i]*1.0;

    }

    

    fwrite(data2,sizeof(DWORD),400*640,fp2);

    

    fclose(fp1);

    fclose(fp2);

    free(data1);

    free(data2);

    

    return 0;

}