变异系数程序

给定一个大小为 n 的数组，任务是找到变异系数。变异系数是标准差与平均值的比值。变异系数的主要目的是通过测量概率或频率分布的总体数据的离散度，或通过确定物质样本数据的含量或质量来寻找质量保证的研究。测量标准偏差与平均值之比的方法也称为相对标准偏差，通常缩写为 RSD。
例子：

Input : arr[] = {60.25, 62.38, 65.32, 61.41, 63.23}
Output : 0.0307144

Input : arr[] = {15, 36, 53.67, 25.45, 67.8, 56, 78.09}
Output : 0.48177

方法：

Coefficient of Variation = Standard deviation / mean 
Example:
arr[] = {60.25, 62.38, 65.32, 61.41, 63.23}
mean = 62.518
Standard Deviation = 1.9202
Coefficient of Variation = Standard deviation / mean
                         = 1.9202 / 62.518
                         = 0.0307144

下面是上述公式的实现：

C++

// Program to find coefficient of
// variation of given array.
#include 
using namespace std;
 
// Function to find mean of given array.
float mean(float arr[], int n)
{
    float sum = 0;
    for (int i = 0; i < n; i++)
        sum = sum + arr[i];
    return sum / n;
}
 
// Function to find standard deviation
// of given array.
float standardDeviation(float arr[], int n)
{
    float sum = 0;
    for (int i = 0; i < n; i++)
        sum = sum + (arr[i] - mean(arr, n)) *
                    (arr[i] - mean(arr, n));
 
    return sqrt(sum / (n - 1));
}
 
// Function to find coefficient of variation.
float coefficientOfVariation(float arr[], int n)
{
   return standardDeviation(arr, n) / mean(arr, n);
}
 
// Driver Program
int main()
{
    float arr[] = { 15, 36, 53.67, 25.45,
                    67.8, 56, 78.09 };
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << coefficientOfVariation(arr, n);
    return 0;
}

Java

//Java Program to find coefficient of
// variation of given array
import java.io.*;
 
class GFG {
 
    // Function to find mean of given array.
    static double mean(double arr[], int n)
    {
        double sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + arr[i];
        return sum / n;
    }
     
    // Function to find standard 
    // deviation of given array.
    static double standardDeviation(double arr[],
                                            int n)
    {
        double sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + (arr[i] - mean(arr, n)) *
                            (arr[i] - mean(arr, n));
     
        return Math.sqrt(sum / (n - 1));
    }
     
    // Function to find coefficient of variation.
    static double coefficientOfVariation(double arr[],
                                                int n)
    {
    return (standardDeviation(arr, n) / mean(arr, n));
    }
 
    // Driver Program
    public static void main (String[] args) {
         
    double arr[] = { 15, 36, 53.67, 25.45,
                              67.8, 56, 78.09 };
    int n = arr.length;
     
    System.out.println( coefficientOfVariation(arr, n));
 
    }
}
 
 
//This article is contributed by vt_m.

Python3

# Program to find coefficient
# of variation of given array.
import math
 
# Function to find mean of
# given array.
def mean(arr, n):
    sum = 0
     
    for i in range(0, n):
        sum = sum + arr[i]
    return (sum / n)
 
# Function to find standard
# deviation of given array.
def standardDeviation(arr, n):
    sum = 0
     
    for i in range(0, n):
        sum = (sum + (arr[i] - mean(arr, n)) *
                      (arr[i] - mean(arr, n)))
 
    return math.sqrt(sum / (n - 1))
 
 
# Function to find coefficient
# of variation.
def coefficientOfVariation(arr, n):
    return (standardDeviation(arr, n) /
                          mean(arr, n))
 
 
# Driver Program
arr = [15, 36, 53.67, 25.45,
            67.8, 56, 78.09]
n = len(arr)
 
print(round(coefficientOfVariation(arr, n), 5))
 
# This code is contributed by Smitha Dinesh Semwal

C#

//C# Program to find coefficient of
// variation of given array
using System;
 
class GFG {
 
    // Function to find mean of given array.
    static float mean(double []arr, int n)
    {
        double sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + arr[i];
        return (float)sum / n;
    }
     
    // Function to find standard
    // deviation of given array.
    static float standardDeviation(double []arr,
                                            int n)
    {
        double sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + (arr[i] - mean(arr, n)) *
                        (arr[i] - mean(arr, n));
     
        return (float)Math.Sqrt(sum / (n - 1));
    }
     
    // Function to find coefficient of variation.
    static float coefficientOfVariation(double []arr,
                                                int n)
    {
        return(float) (standardDeviation(arr, n) / mean(arr, n));
    }
 
    // Driver Program
    public static void Main () {
         
    double []arr = { 15, 36, 53.67, 25.45,
                            67.8, 56, 78.09 };
    int n = arr.Length;
     
    Console.WriteLine( coefficientOfVariation(arr, n));
 
    }
}
 
 
// This code is contributed by vt_m.

PHP

Javascript

输出：

0.48177