demoapriori.java

贝叶思网络分类规则例程

import java.io.*;
import Apriori;

public class DemoApriori
{
  public static void main( String [] args ) throws IOException
  {

    if( args.length < 3 )
    {
      System.err.println("<datafilename> <int support> <float confidence>");
      System.exit(1);
    }

    Apriori apriori = new Apriori();
    String inputFileName = args[0];
    int minSup = Integer.parseInt(args[1]);
    float minConf = Float.parseFloat(args[2]);    

    System.err.println(inputFileName+" "+minSup+" "+minConf);
    printRules( apriori.go( getInput(inputFileName), minSup, minConf ) );
  }

  //
  // Print out the rules
  //
  private static void printRules( RuleSet ruleSet )
  {
    Object o[] = ruleSet.toArray();
    for(int i=0; i<o.length; i++)
    {
      Rule rule = (Rule)o[i];
      System.out.print( "Rule:");
      System.out.print( translate(rule.getLhs()) );
      System.out.print( "==>" );
      System.out.print( translate(rule.getRhs()) );
      System.out.print( " (confidence="+rule.getConfidence() );
      System.out.println( " support="+rule.getSupport()+")");
    }
  }

  //
  // Translate the integers into their column headings
  //
  private static String translate( ItemSet s )
  {
    String outStr = new String();

    Object o[] = s.toArray();
    for(int i=0; i<o.length; i++)
    {
      Integer x = (Integer)o[i];
      outStr = new String(outStr + translateElement(x));
      if( i != (o.length-1) )
        outStr = new String(outStr + " and ");
    }   
  return outStr;
  }

  //
  // Determine column heading by int value
  //
  public static String translateElement(Integer i)
  {
    String outStr;

    if( i.compareTo(new Integer(20000)) < 0 ) // i < 20000
      outStr=new String("origin="+(i.intValue()-10000));
    else
    if( i.compareTo(new Integer(30000)) < 0 ) // i < 30000
      outStr=new String("cylinders="+(i.intValue()-20000));
    else
    if( i.compareTo(new Integer(40000)) < 0 ) // i < 40000
      outStr=new String("mpg="+(i.intValue()-30000));
    else
    if( i.compareTo(new Integer(50000)) < 0 ) // i < 50000
      outStr=new String("acceleration="+(i.intValue()-40000));
    else
    if( i.compareTo(new Integer(60000)) < 0 ) // i < 60000
      outStr=new String("modelyear="+(i.intValue()-50000));
    else
    if( i.compareTo(new Integer(70000)) < 0 ) // i < 70000
      outStr=new String("displacement="+(i.intValue()-60000));
    else
    if( i.compareTo(new Integer(80000)) < 0 ) // i < 80000
      outStr=new String("horsepower="+(i.intValue()-70000));
    else
    if( i.compareTo(new Integer(90000)) < 0 ) // i < 90000
      outStr=new String("weight="+(i.intValue()-80000));
    else
      outStr=new String("catchall="+i);
    
  return outStr;        
  }

  //
  // Read text file into ItemSets
  //
  private static ItemSet getInput(String name) throws IOException
  {
    ItemSet set = new ItemSet();
    
    try
    {
      File file = new File(name);
      FileReader is = new FileReader(file);
      Reader r = new BufferedReader(is);
      StreamTokenizer st = new StreamTokenizer(r);
      st.eolIsSignificant(true);

      st.nextToken();
      while( st.ttype != st.TT_EOF )
      {
        ItemSet s = new ItemSet();
        int k=1;
        while( st.ttype != st.TT_EOL )
        {
          s.add(new Integer((int)st.nval+k*10000));
          st.nextToken();
          k++;
        }
        set.add(s);
        st.nextToken();
      }
    }
    catch ( IOException e )
    {
      System.err.println(e.toString());
      System.exit(1);
    }

  return set;
  }

}