JAVA Link from instruction httpenwikipediaorgwikiStandarddev

JAVA

Link from instruction

http://en.wikipedia.org/wiki/Standard_deviation

Code from instruction

public class stdev {

    public static void main(String[] args) {

        double [] d = new double[10];

        for(int i = 1; i <=10; i++)

        d[i-1]=i;

        double total = 0;

        double average = 0;

        for(int i = 0; i < 10; i++)

        total += d[i];

        average = total/10;

        System.out.println(\"average \"+average);

        total = 0;

        for(int i = 0; i < 10; i++)

        total += (d[i] - average)*(d[i]-average);

        total /= 9;

        double std = Math.sqrt(total);

        System.out.println(\"Stdev = \" + std);

    }

}

Write a generic class MyMathClass with at type parameter T where Tis a numeric object (Integer, Double or any class that extends jayalang-number) Add a method standardDeviation (stdev) that takes an ArrayList of type Tand returns a standard deviation as type double. Use a for each loop where appropriate Hard code a couple of test arrays into your Demo file. You must use at least 2 different types such as Double and Integer Your call will be something like: System. out.println Standard Deviation 0-9 MyMathClass. stdev (a)) Your class and method headers will be: public class MyMathClass KT extends Number public static KT extends Number double stdev (ArrayList a) Research java\' s Number class to see what useful method we are gaining access to Standard Deviation is the average amount of deviation from the average See http://en wikipedia.org/wiki/Standard deviation The formula that must be implemented is N ari i-1 Where the x with a bar over it is the average. The greek letter sigma stands for a summation So you need to take each element in the array, subtract the average from it, square it and add this number to a tota After you take the total divide by the number of elements 1 and take the square root. Example Tf the input is 1 2 3 4 5 6 7 8 9 10. The average is 5.5 The result for the total would be: 5.5 5.5) (2 5.5) (3 5.5 3-5.5 (10 5.5 10 5.5

Solution

Hi, I have implemented program.

Please let me know in case of any issue.

import java.util.ArrayList;

public class MyMathClass<T extends Number> {

   public static <T extends Number> double standardDeviation(ArrayList<T> list){

      

       double total = 0;

double average = 0;

for(T x : list)

   total = total + x.doubleValue();

  

average = total/10;

   // System.out.println(\"average \"+average);

total = 0;

for(T x : list){

   double d = x.doubleValue();

   total += (d - average)*(d-average);

}

total /= 9;

double std = Math.sqrt(total);

      

       return std;

   }

  

   public static void main(String[] args) {

      

       ArrayList<Double> dList = new ArrayList<>();

       ArrayList<Integer> iList = new ArrayList<>();

       for(int i=1; i<=10; i++){

           dList.add((double) i);

           iList.add(i);

       }

      

       double dDev = MyMathClass.standardDeviation(dList);

       double iDev = MyMathClass.standardDeviation(iList);

      

       System.out.println(\"standard deviation 0-9 type Double \"+dDev);

       System.out.println(\"standard deviation 0-9 type Integer \"+iDev);

      

   }

}

/*

Sample output:

standard deviation 0-9 type Double 3.0276503540974917

standard deviation 0-9 type Integer 3.0276503540974917

*/