计算C语言中的求和、标准差、方差和标准差等，需要加上头文件：#include
#include#include "math.h"
double sum = 0;//求和
double array[4] = {1.2,2.1,3.1,4.1};
int length = 0;//数组长度
double average = 0;//求平均数
double var = 0; //求方差
double standard = 0; //求标准差
int main()
{
for (int i = 0; i <= 3;i++)
{
sum += array[i];//求和
}
length = sizeof(array) / sizeof(array[0]);//求数组长度
average = sum / length;//求平均值
for (int j = 0; j <= 3;j++)
{
var += pow(array[j]-average,2)/length;//求方差
}
standard = pow(var,0.5);//求标准差
printf("sum = %gn",sum);//这边打印也可以使用printf("%fn",sum);这种打印默认出来的数是小数点后6位
printf("length of array[4] = %dn",length);
printf("average = %gn",average);
printf("var = %gn",var);
printf("standard = %gn",standard);
while (1);
return 0;
}
补充知识：C语言：计算并输出给定10个数的方差
//计算并输出给定10个数的方差。
#include#includedouble fun(double x[10])
{
double p = 0.0,f=0.0,g=0.0;
for (int i = 0; i < 10; i++)
{
p += x[i];
}
p = p / 10;
printf("%fn", p);
for (int j = 0; j < 10; j++)
{
g = x[j] - p;
f += g*g;
printf("%fn", f);
}
f = f / 10;
f = sqrt(f);
return f;
}
void main()
{
FILE *wf;
double s,x[10]={95.0,89.0,76.0,65.0,88.0,72.0,85.0,81.0,90.0,56.0};
int i;
printf("nThe original data is:n");
for(i=0;i<10;i++)
printf("%6.1f ",x[i]);
printf("nn ");
s=fun(x);
printf("s=%fnn ",s);
/******************************/
wf=fopen("out.dat","w");
fprintf(wf,"%f",s);
fclose(wf);
/*****************************/
}
以上这篇C语言中求和、计算平均值、方差和标准差的实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。