平均绝对偏差程序

给定大小为n的数组，求平均绝对偏差。
先决条件：均值，方差和标准差
例子：

Input : arr[] = {10, 15, 15, 17, 18, 21}
Output : 2.66667

Input : arr[] = {23.54, 56, 34.56, 67, 45.34,  
                              56.78, 78, 21}
Output : 16.6675

Mean absolute deviation or Average absolute deviation of data set is the average of absolute difference from mean or central point.Mean absolute deviation can be calculated by using the method given below. 
Let arr[n] be an array of size n and the task is to find mean absolute deviation. 
Mean absolute deviation = (abs(arr[0] – mean) + abs(arr[1] – mean) + . . . + abs(arr[n-1] – mean) / n; 
where i = 0, 1, 2, . . . n-1 and “abs” is absolute difference. 
mean = (arr[0] + arr[1] + arr[2] + . . . + arr[n-1]) / n; 
 

C++

// C++ Program to find mean absolute
// deviation of given array.
#include 
using namespace std;
 
// Function to find mean
// of the array elements.
float Mean(float arr[], int n)
{  
    // Calculate sum of all elements.
    float sum = 0;
    for (int i = 0; i < n; i++)
        sum = sum + arr[i];
    return sum / n;
}
 
// Function to find mean absolute
// deviation of given elements.
float meanAbsoluteDeviation(float arr[], int n)
{  
    // Calculate the sum of absolute
    // deviation about mean.
    float absSum = 0;
    for (int i = 0; i < n; i++)
        absSum = absSum + abs(arr[i] - Mean(arr, n));
 
    // Return mean absolute deviation about mean.
    return absSum / n;
}
 
// Driver function.
int main()
{
    float arr[] = { 10, 15, 15, 17, 18, 21 };
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << meanAbsoluteDeviation(arr, n);
    return 0;
}

Java

// java Program to find mean absolute
// deviation of given array
import java.io.*;
 
class GFG {
         
    // Function to find mean
    // of the array elements.
    static float Mean(float arr[], int n)
    {
        // Calculate sum of all elements.
        float sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + arr[i];
         
        return sum / n;
    }
     
    // Function to find mean absolute
    // deviation of given elements.
    static float meanAbsDevtion(float arr[],
                                       int n)
    {
        // Calculate the sum of absolute
        // deviation about mean.
        float absSum = 0;
         
        for (int i = 0; i < n; i++)
            absSum = absSum + Math.abs(arr[i]
                                - Mean(arr, n));
     
        // Return mean absolute
        // deviation about mean.
        return absSum / n;
    }
     
        // Driver function.
        public static void main (String[] args) {
         
        float arr[] = { 10, 15, 15, 17, 18, 21 };
        int n = arr.length;
         
            System.out.println(meanAbsDevtion(arr, n));
        }
}
 
 
// This code is contributed by vt_m

Python3

# Python 3 Program to find
# mean absolute deviation
# of given array.
 
# Function to find mean
# of the array elements.
def Mean(arr, n) :
 
    # Calculate sum of all
    # elements.
    sm = 0
     
    for i in range(0, n) :
        sm = sm + arr[i]
    return sm // n
     
# Function to find mean
# absolute deviation of
# given elements.
def meanAbsoluteDeviation(arr, n) :
     
    # Calculate the sum of
    # absolute deviation
    # about mean.
    absSum = 0
    for i in range(0, n ):
        absSum = absSum + abs(arr[i] -
                         Mean(arr, n))
 
    # Return mean absolute
    # deviation about mean.
    return absSum / n
 
# Driver function.
arr = [ 10, 15, 15, 17, 18, 21 ]
n = len(arr)
 
print(meanAbsoluteDeviation(arr, n))
 
# This code is contributed by Nikita Tiwari.

C#

// C# Program to find mean absolute
// deviation of given array
using System;
 
class GFG {
         
    // Function to find mean
    // of the array elements.
    static float Mean(float []arr, int n)
    {
        // Calculate sum of all elements.
        float sum = 0;
         
        for (int i = 0; i < n; i++)
            sum = sum + arr[i];
         
        return sum / n;
    }
     
    // Function to find mean absolute
    // deviation of given elements.
    static float meanAbsDevtion(float []arr,
                                    int n)
    {
        // Calculate the sum of absolute
        // deviation about mean.
        float absSum = 0;
         
        for (int i = 0; i < n; i++)
            absSum = absSum + Math.Abs(arr[i]
                                - Mean(arr, n));
     
        // Return mean absolute
        // deviation about mean.
        return absSum / n;
    }
     
        // Driver function.
        public static void Main ()
        {
             
            float []arr = { 10, 15, 15, 17, 18, 21 };
            int n = arr.Length;
         
            Console.WriteLine(meanAbsDevtion(arr, n));
        }
}
 
 
// This code is contributed by vt_m

Javascript

 
// JavaScript Program to find mean absolute
// deviation of given array
 
    // Function to find mean
    // of the array elements.
    function Mean(arr, n)
    {
        // Calculate sum of all elements.
        let sum = 0;
           
        for (let i = 0; i < n; i++)
            sum = sum + arr[i];
           
        return sum / n;
    }
       
    // Function to find mean absolute
    // deviation of given elements.
    function meanAbsDevtion(arr, n)
    {
        // Calculate the sum of absolute
        // deviation about mean.
        let absSum = 0;
           
        for (let i = 0; i < n; i++)
            absSum = absSum + Math.abs(arr[i]
                                - Mean(arr, n));
       
        // Return mean absolute
        // deviation about mean.
        return absSum / n;
    }
 
// Driver code
        let arr = [ 10, 15, 15, 17, 18, 21];
        let n = arr.length;
           
        document.write(meanAbsDevtion(arr, n));
  
 // This code is contributed by sanjoy_62.

输出：

2.66667