public override string Summarize(string text, string lang = "en")
{
var sentences = SplitTextOnSentences(text);
int summarySize = 3;
if (sentences.Count <= summarySize)
{
return(text);
}
_stopWordFilter = _nlpServiceProvider.GetStopWordFilter(lang);
var stemmer = _nlpServiceProvider.GetStemmer(lang);
var tokenizedSentences = new List <IList <string> >();
foreach (var sentence in sentences)
{
var tokenizer = new TextTokenizer(sentence, filterMapper: new TextFilterMapper {
Map = (t) => stemmer.Stem(t)
});
tokenizedSentences.Add(tokenizer.ToList());
}
var matrix = BuildSimilarityMatrix(tokenizedSentences);
var graph = BuildDirectedGraph(matrix);
var result = new PageRank()
.Rank(graph)
.OrderBy(kv => kv.Value); //Less value, better result
var summary = "";
var topSentances = result.Take(summarySize).OrderBy(kv => kv.Key); //Sentences order in text
foreach (var topSent in topSentances)
{
summary += sentences[topSent.Key] + ". ";
}
return(summary);
}