private static double redundancyPenalty(Sentence firstSentence, Sentence secondSentence)
{
double redundancy = 0;
HashSet <string> commonWords = SummaryUtil.getCommonWords(firstSentence, secondSentence);
redundancy = (double)(2 * commonWords.Count) / (double)(firstSentence.words.Count + secondSentence.words.Count);
return(redundancy);
}
public static double sim(IDF idf, Hashtable first, Hashtable second)
{
double similarity = 0;
HashSet <string> commonWords = SummaryUtil.getCommonWords(new ArrayList(first.Keys), new ArrayList(second.Keys));
double numerator = 0;
foreach (string aWord in commonWords)
{
numerator += ((double)first[aWord] * (double)second[aWord] * idf.get(aWord));
}
double denominator1 = 0;
foreach (string aWord in first.Keys)
{
//if (docStats.wordRefs[aWord] != null)
denominator1 += Math.Pow((double)first[aWord], 2);
}
denominator1 = Math.Sqrt(denominator1);
double denominator2 = 0;
foreach (string aWord in second.Keys)
{
//if (docStats.wordRefs[aWord] != null)
denominator2 += Math.Pow((double)second[aWord], 2);
}
denominator2 = Math.Sqrt(denominator2);
similarity = numerator / (denominator1 * denominator2);
return(similarity);
}