HookaStats.java

package ivory.core.util;

public class HookaStats {
  private int cntLongTail, cntShortTail, sumShortTail, sumLongTail, numTopTrans;
  private float sumCumProbs, cumProbThreshold;
  
  
  public HookaStats(int n, float c) {
    cntLongTail = 0;
    cntShortTail = 0;
    sumShortTail = 0;
    sumLongTail = 0;
    sumCumProbs = 0f;
    numTopTrans = n;
    cumProbThreshold = c;
  }

  public int getCntLongTail() {
    return cntLongTail;
  }

  public void incCntLongTail(int n) {
    this.cntLongTail += n;
  }

  public int getCntShortTail() {
    return cntShortTail;
  }

  public void incCntShortTail(int n) {
    this.cntShortTail += n;
  }

  public int getSumShortTail() {
    return sumShortTail;
  }

  public void incSumShortTail(int n) {
    this.sumShortTail += n;
  }
  
  public void incSumLongTail(int n) {
    this.sumLongTail += n;
  }

  public float getSumCumProbs() {
    return sumCumProbs;
  }

  public void incSumCumProbs(float n) {
    this.sumCumProbs += n;
  }
  
  public void update (int numEntries, float sumOfProbs) {
    // if number of translations not set, we never cut-off, so all cases are long tails 
    if ( numTopTrans != Integer.MAX_VALUE && numEntries < numTopTrans ) {
      incCntShortTail(1);
      incSumShortTail(numEntries);
    }else {
      incCntLongTail(1);
      incSumLongTail(numEntries);
      incSumCumProbs(sumOfProbs);
    }
  }
  
  public String toString () {
    String s = "";
    s += "# source terms with ~ " + cumProbThreshold + " probability covered: " + cntShortTail 
      + " and average translations per term: " + (sumShortTail / (cntShortTail + 0.0f)) + "\n";
    
    float averageCoverageLongTail = cntLongTail == 0 ? -1 : sumCumProbs / cntLongTail;
    s += "# source terms with <= " + cumProbThreshold + " probability covered: " + cntLongTail 
      + " (each have " + ( numTopTrans == Integer.MAX_VALUE ? "inf" : numTopTrans ) + " translations). " 
      +	"Average coverage is: " + ( averageCoverageLongTail == -1 ? "N/A" : averageCoverageLongTail ) + "\n";
    
    float averageCoverageOverall = ( cntShortTail * cumProbThreshold + sumCumProbs ) / ( cntShortTail + cntLongTail );
    s += "Size (total number of dictionary entries) = " + ( sumShortTail + sumLongTail ) 
      + " TTable average coverage >= " + averageCoverageOverall;
    
    return s;
  }
  
  
}