嘿,我很難搞清楚如何計算Java中數組的標準占卜數。正如你所看到的,我已經計算了平均值,而且我知道最後我將不得不除以樣本量減去1(n-1)並平均該數值。我遇到的問題是如何獲取每個數字並計算距離平均值有多遠,然後計算該數字。我知道我可以分別從數據集中完成每個數字,但必須有一個更簡單的方法。任何幫助將不勝感激,這是我的代碼。任何大小數組的標準偏差java
public class CalculateArray
{
public static void main(String[] args)
{
int [] numbers = new int[]{1,2,3,4,5,6,7,8,9};
int sum = 0;
int max = 0;
int min = numbers[0];
double sd = 0;
for(int i=0; i<numbers.length; i++)
{
sum = sum + numbers[i];
}
double average = sum/numbers.length;
System.out.println("Average value is : " + average);
for(int i=0; i<numbers.length; i++)
{
if(numbers[i] > max)
{
max = numbers[i];
}
}
System.out.println("max number is : " + max);
for(int i=0; i<numbers.length; i++)
{
if(numbers[i] < min)
{
min = numbers[i];
}
}
System.out.println("min number is : " + min);
for (int i=0; i<numbers.length;i++)
{
//this is where im having problems
sd = ???
}
double standardDeviation = math.sqrt(sd/(numbers.length-1));
System.out.println("The standard deviation is : " + standardDeviation);
}
}
'std + = pow(average - numbers [i],2)''? – imreal 2013-02-12 18:20:11