/// <summary>
/// Trains this Category from a word or phrase<\summary>
/// <seealso cref="DePhrase(string)">
/// See DePhrase </seealso>
public void TeachPhrase(string rawPhrase, bool useWordStemmer = false)
{
rawPhrase = rawPhrase.ToLower(); // Eliminate case-sensitivity
if ((null != m_Excluded) && (m_Excluded.IsStopword(rawPhrase)))
{
return;
}
BayesPhraseCount pc;
string Phrase = GetWordStem(DePhrase(rawPhrase), useWordStemmer);
rawPhrase = GetWordStem(rawPhrase, useWordStemmer); // Reduce the words to their "stems" so that something like "birds" matches "bird"
if (!m_Phrases.TryGetValue(Phrase, out pc))
{
pc = new BayesPhraseCount(rawPhrase);
m_Phrases.Add(Phrase, pc);
}
pc.Count++;
m_TotalWords++;
}
/// <summary>
/// Classifies a text<\summary>
/// <returns>
/// returns classification values for the text, the higher, the better is the match.</returns>
public Dictionary <string, double> Classify(System.IO.StreamReader tr, bool useWordStemmer = false)
{
Dictionary <string, double> score = new Dictionary <string, double>();
foreach (KeyValuePair <string, IBayesCategory> cat in m_Categories)
{
score.Add(cat.Value.Name, 0.0);
}
BayesEnumerableCategory words_in_file = new BayesEnumerableCategory("", m_ExcludedWords);
words_in_file.TeachCategory(tr, useWordStemmer);
foreach (KeyValuePair <string, BayesPhraseCount> kvp1 in words_in_file)
{
BayesPhraseCount pc_in_file = kvp1.Value;
foreach (KeyValuePair <string, IBayesCategory> kvp in m_Categories)
{
IBayesCategory cat = kvp.Value;
int count = cat.GetPhraseCount(pc_in_file.RawPhrase);
if (0 < count)
{
score[cat.Name] += System.Math.Log((double)count / (double)cat.TotalWords);
}
else
{
score[cat.Name] += System.Math.Log(0.01 / (double)cat.TotalWords);
}
//System.Diagnostics.Trace.WriteLine(string.Format("{0}({1}){2}", pc_in_file.RawPhrase.ToString(), cat.Name, score[cat.Name]));
}
}
int totalWordsinCats = this.CountTotalWordsInCategories();
foreach (KeyValuePair <string, IBayesCategory> kvp in m_Categories)
{
IBayesCategory cat = kvp.Value;
score[cat.Name] += System.Math.Log((double)cat.TotalWords / (double)totalWordsinCats);
}
return(score);
}
