Listing 1

package stat;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Collections;
import java.util.HashMap;

public class Stats {

 public ArrayList nums;

 public Stats(ArrayList someNums){
  nums = new ArrayList(someNums);
 }

 public Stats(double[] someNums){
  nums = new ArrayList(someNums.length);

  for (int index=0; index  < someNums.length; index++){
    nums.add(new Double(someNums[index]));
  }
 }
 
 

 public double getMean (){
  return this.getMean(true);
 }

 public double getMean (boolean sample){
  // Define mean that finds two types of mean, namely:
  // population mean and sample mean
  double sum=0.0;
  double average=0.0;
  Iterator iterator = nums.iterator();

  while(iterator.hasNext())
   sum = sum + ((Double)iterator.next()).doubleValue();
 

   // Check to see if this is a sample mean
  if(sample)
   average = sum / nums.size()-1;
  else
   average = sum / nums.size();

  return average;
 }

 public ArrayList getRange (){
   // Find the range. Returns a tuple with the minimum,
   // maximum, and range value
  double min, max;
  ArrayList ranges;

  min = ((Double)Collections.min(nums)).doubleValue();
  max = ((Double)Collections.max(nums)).doubleValue();
 

  ranges = new ArrayList();
  ranges.add(new Double (min));
  ranges.add(new Double (max));
  ranges.add(new Double (max-min));

  return ranges;
 }

 public double getMedian (){
  // Find the Median number

   // create a duplicate since we are going to modify the
   // sequence
  ArrayList seq = new ArrayList(nums);

   // sort the list of numbers
  Collections.sort(seq);

  double median = 0.0; // to hold the median value

  int length = seq.size(); // to hold the length of the
                         // sequence
  int index=0;

   // Check to see if the length is an even number
  if ( ( length % 2) == 0){
    // since it is an even number
    // add the two middle number together
   index = length / 2;
   double m1 = ((Double)seq.get(index-1)).doubleValue();
   double m2 = ((Double)seq.get(index)).doubleValue();
   median = (m1 + m2) /2.0;
  }
  else{
    // since it is an odd number
    // just grab the middle number
   index = (length / 2);
   median = ((Double)seq.get(index)).doubleValue();
  }
  return median;

 }

 private int countMode(Object object, ArrayList list){
  int index = 0;
  int count = 0;
  do {
   index = Collections.binarySearch(list, object);
   if(index >=0)list.remove(index);
   count++;
  }
  while (index >=0);
  return count;
 }

 public double getMode (){
  // Find the number that repeats the most.

   // make a duplicate copy of the nums argument
  ArrayList duplicate = new ArrayList(nums);

  Collections.sort(duplicate);
  double highest_count = -100;
  double mode = -100;
 

  Iterator iterator = nums.iterator();
   // iterate through nums removing each item out of the duplicate
   // calculate the highest_count and the mode
  while(iterator.hasNext()){
   double count = 0;
   Object item = iterator.next();

    // Count the number of times the item occurs in the list
    // If Count is 0 go to the next iteration
   count = countMode(item, duplicate);
   if (count == 0) continue;

    // determine the highest count. The highest counted item is the mode.
   if (count > highest_count){
    highest_count = count;
    mode = ((Double)item).doubleValue();
   }
  }
 

  return mode;
 }

}

Listing 2

print "The mode of the houses is %2.2f" %  houses.mode
print "The mean of the houses is %2.2f" % houses.mean
print "The median of the houses is %2.2f" % houses.median

Listing 3

import com.ibm.cs.util.IOUtils;
import com.ibm.bsf.BSFManager;
import com.ibm.bsf.BSFEngine;
import java.io.FileReader;
import stat.Stats;

class Test {
 public static void main (String [] args){
  BSFManager manager = new BSFManager ();
 

   //Register JPython into the scripting manager.
  String[] extensions = {"py"};
  manager.registerScriptingEngine ("jpython",
     "com.ibm.bsf.engines.jpython.JPythonEngine",
     extensions);

  try{
    //Load JPython engine
   BSFEngine jpythonEngine = manager.loadScriptingEngine ("jpython");

    //Execute an expression.
   Object result = manager.eval ("jpython", "testString", 0, 0, "2+32");
   System.out.println("eval="+result);

    //Map some objects that the script will use.
   double[] houses=new double [] {100.0e3, 130.0e3, 140e3, 150e3};
   Stats stats = new Stats(houses);
   manager.declareBean("houses", stats, Stats.class);

    //Load the script and execute it.
   String fileName = "TestStat2.py";
   String language = manager.getLangFromFilename(fileName);
   String script = IOUtils.getStringFromReader(new FileReader(fileName));
   manager.exec(language, fileName, 0, 0, script);

  }//try
  catch (Exception e){
   System.out.println(""+e);
  }//catch

 }//main
}//Test