c语言 除法用float可以用 double就出错是怎么回事0

gi24362013.03.22浏览112次分享举报

#include "stdlib.h"

#include "stdio.h"

FILE *fp;

double *linspace(double,double,int);

int main(void){

double start,end;

int Npoint,i;

double *result;

printf("input start and end :!\n");

scanf(" %f %f",&start,&end);

printf("intput Npoint\n");

scanf(" %d",&Npoint);

result=linspace(start,end,Npoint);

if((fp=fopen("lin.dat","w"))==NULL){

printf("error when open the file lin.dat.\n");

return 1;

}

for(i=0;i

// printf("%f\n",result[i]);

fprintf(fp,"%f\n",result[i]);

}

free(result);

fclose(fp);

return 0;

}

double *linspace(double start,double end,int Npoint){

double *data;

double interval;

int i;

data=(double *)malloc(Npoint*sizeof(double));

interval=(end-start)/(Npoint-1);

printf("interval is %f\n",interval);

data[0]=start;

for(i=1;i

data[i]=data[i-1]+interval;

}

return data;

}

源程序如上，把double改成float就能正常运行，

我判断不正常的依据是 interval=(end-start)/(Npoint-1);

这个interval的输出结果不正确。