说明：  稀疏矩阵用于文本挖掘的实验平台，TREC数据评价的API借口
(The Dragon Toolkit is a Java-based development package for academic use in information retrieval (IR) and text mining (TM, including text classification, text clustering, text summarization, and topic modeling). It is tailored for researchers who work on large-scale IR and TM and prefer Java programming. Moreover, different from Lucene and Lemur, it provides built-in supports for semantic-based IR and TM. The dragon toolkit seamlessly integrates a set of NLP tools, which enable the toolkit to index text collections with various representation schemes including words, phrases, ontology-based concepts and relationships. )