/* Provide Statistics on Annual Data

// Constructor & Accessors
   public AnnualDataSet(double[] items)
   public double[] getData()
   public double getData(String month)
   
// Other Methods
   public double average()
   public double minimum()
   public double maximum()
   public double median()
   public double standardDeviation()
   public String monthOfMaximum()
   public String monthOfMinimum()
*/
import java.util.*;
public class AnnualDataSet
{
   public static final int MONTHS_IN_YEAR = 12;
   
   public static final String[] MONTHS = 
          {"January", "February", "March", "April", "May", "June", "July", 
           "August", "September", "October", "November", "December"};
   
   //Instance Variable: 1 element for each month
   // data[0]: January,  data[1]: February, ... data[11]: December
   private double[] data;
   
   //Constructor
   public AnnualDataSet(double[] items)
   {
      if (items.length != MONTHS_IN_YEAR )
         throw new RuntimeException("12 Data Items Expected"); 
       
      this.data = new double[MONTHS_IN_YEAR];
      
      for (int index = 0; index < this.data.length; index++)
         this.data[index] = items[index];
   }
   
   //Accessor - return all data items
   public double[] getData()
   {
      //return this.data;
      
      double[] info = new double[ this.data.length ];
      for (int index = 0; index < info.length; index++)
         info[index] = this.data[index];
         
      return info;
   }
   
   //Return the total of the data set
   private double total()
   {
      double sum = 0.0;
/*      
      for (int i = 0; i < data.length; i++)
         sum = sum + data[i];
*/         
      for (double item : this.data)
         sum = sum + item; 
            
      return sum;
   }
   
   //Return the average of the data set
   public double average()
   {
      return this.total() / this.data.length;
   }
   
   //Return the smallest item in the data set
   public double minimum()
   {
      double min = this.data[0];
      for (double value : this.data)
         if ( value < min )
            min = value;
            
      return min;
   }
   
   //Return the largest item in the data set
   public double maximum()
   {
      double max = this.data[0];
      for (double value : this.data)
         if ( value > max )
            max = value;
            
      return max;
   }

   //Return the median value of the data set
   public double median()
   {
      //Sort the data
      return (this.data[5] + this.data[6]) / 2.0;
   }
         
   //Return the standard deviation of the data set
   public double standardDeviation()
   {
      return Math.sqrt( this.variance() );
   }
   
   //---------------------------------------------------------------------
   //Accessor - return the data for a single month
   public double getData(String month)
   {
      for (int index = 0; index < this.data.length; index++)
         if ( month.equalsIgnoreCase( MONTHS[index] ) )
            return this.data[ index ] ;

      throw new RuntimeException("Invalid Month Name " + month);
   }
              
   //Return the month with the highest data item in the set
   public String monthOfMaximum()
   {
       return MONTHS[ this.indexOfMax() ];
   }
   
   //Return the month with the smallest data item in the set
   public String monthOfMinimum()
   {
      return MONTHS[ indexOfMin() ];
   }
   
   //Helper: Find the index of the smallest data item
   private int indexOfMax()
   {
      int maxi = 0;
      for (int index = 0; index < this.data.length; index++)
         if ( this.data[index] > this.data[maxi] )
            maxi = index;
      return maxi;
   }
   
   //Helper: Find the index of the smallest data item
   private int indexOfMin()
   {
      int mini = 0;
      for (int index = 0; index < this.data.length; index++)
         if ( this.data[index] < this.data[mini] )
            mini = index;
      return mini;
   }
   
   //Helper: Return the variance of the data set
   private double variance()
   {
      double mean = this.average();

      double total = 0.0;
      
      for (double item : this.data)
         total = total + (item - mean) * (item - mean);
         
      return total / this.data.length;
   }

/* Alternative method implementations

   public double maximum()
   {
      return this.data[ this.indexOfMax() ];
   }
   
   public double minimum()
   {
      return this.data[ this.indexOfMin() ];
   }
   
*/   
}