計算標準差 Exercise07_11
阿新 • • 發佈:2018-12-25
1 import java.util.Scanner; 2 /** 3 * @author 冰櫻夢 4 * 時間:2018年下半年 5 * 題目:計算標準差 6 * 7 */ 8 public class Exercise07_11 { 9 public static void main(String[] args){ 10 Scanner input=new Scanner(System.in); 11 double[] array=new double[10]; 12 System.out.println("Enter 10 numbers: ");13 for(int i=0;i<array.length;i++){ 14 array[i]=input.nextDouble(); 15 } 16 System.out.printf("%s%.2f\n","The mean is: ",mean(array)); 17 System.out.printf("%s%.5f","The standard deviation is: ",deviation(array)); 18 } 19 20 //返回陣列的平均值 21 publicstatic double mean(double[] x){ 22 double total=0; 23 for(int i=0;i<x.length;i++){ 24 total+=x[i]; 25 } 26 return total/x.length; 27 } 28 29 //返回陣列的標準差 30 public static double deviation(double[] x){ 31 double total=0; 32 for(inti=0;i<x.length;i++){ 33 total+=Math.pow((x[i]-mean(x)),2); 34 } 35 return Math.pow(total/(x.length-1), 0.5); 36 } 37 }