Calculate standard deviation in Java

Calculate standard deviation in Java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

///////////////////
// SixthJava.java
// 
// javac SixthJava.java
//
// produces SixthJava.class
//
// To execute 
// ----------
// java SixthJava < list of arguments>
// 
//
//
//

// 
class SumComputer {
  private double[] _c;

        //
        //  SumComputer a = new SumComputer (arr);
  //  
  public SumComputer (double [] c) {
          _c = c;  
  }
        //
        // double x = a.SUM();
        public double SUM()
  {
    double sum = 0;
    int n = _c.length;
    int k = 0;
    for(k = 0;k<n;++k) {
      sum = sum + _c[k];    
    }
    return sum;
  }
  public double Average()
  {
    int n = _c.length;
    return this.SUM()/n ; 
  }
  public double StandardDeviation()
  {
    
    double av = Average();
    int n = _c.length;
    double sum = 0;
    int k = 0;
    for(k = 0; k<n;++k) {
      double temp = (_c[k] - av)*(_c[k] - av);
      sum = sum + temp;
    }
    double var = sum/n;
    return Math.sqrt(var);
  }
}

class StringArraytoDoubleArray {
  
  private double[] _temp;
  public StringArraytoDoubleArray (String [] tmp) {
    int n = tmp.length;
    _temp = new double[n];
    for(int i = 0;i < n;i++) {
    _temp[i] = Double.parseDouble(tmp[i]);
          }
    
  }

  public double[] get() {
    return _temp;  
  }
}

public class stdDemo
{

  public static void main(String[] args)
  {
        //
  // retreive the number of arguments
   //int n = args.length;
   //System.out.println(n); 
  //
  // declare a double array (vector)  
  //double [] arr = new double[n];
  //
  // converting strings into double array
  //for(int i = 0;i < n;i++) {
  //  arr[i] = Double.parseDouble(args[i]);
  //}

        StringArraytoDoubleArray s= new StringArraytoDoubleArray(args);
  double[] arr = s.get ();
  
  //
  // computing the sum of the contents of double array
  //double sum = 0;
  //int k = 0;
  //while (k < n) {
  //  sum = sum + arr[k];
         //        k = k+1;
  //}

        SumComputer a = new SumComputer (arr);
  double x = a.StandardDeviation ();
  //
  // printing the sum
  System.out.println(x);
  }



}