public Dictionary <string, double> ExtractWordFrequency(string documentText)
{
string[] words = tokenizer.SplitToWords(documentText);
ImmutableHashSet <string> stopWords = stopWordsProvider.GetStopWords();
words = words.Where(w => !stopWords.Contains(w.ToLower())).ToArray();
for (int i = 0; i < words.Length; ++i)
{
words[i] = stemmer.Stem(words[i]);
}
int totalCount = words.Length;
Dictionary <string, double> result = wordCounter.CountWordFrequencies(words);
return(result);
}