基于Ruby实现pagerank算法.zip

###About This gem implements a PageRank class and a class that allows to perform keyword ranking using the TextRank algorithm. ###Install ``` gem install graph-rank ``` ###Usage **TextRank** > Reference: R. Mihalcea and P. Tarau, “TextRank: Bringing Order into Texts,” in Proceedings of EMNLP 2004. Association for Computational Linguistics, 2004, pp. 404–411. ```ruby text = 'PageRank is a link analysis algorithm, named after Larry ' + 'Page and used by the Google Internet search engine, that assigns ' + 'a numerical weighting to each element of a hyperlinked set of ' + 'documents, such as the World Wide Web, with the purpose of "measuring"' + 'its relative importance within the set.' tr = GraphRank::Keywords.new tr.run(text).inspect ``` Optionally, you can pass the n-gram size (default = 3), as well as the damping and convergence (see PageRank) to the constructor. Finally, you can set stop words as follows: ```ruby tr.stop_words = ["word", "another", "etc"] ``` **PageRank** > Reference: Brin, S.; Page, L. (1998). "The anatomy of a large-scale hypertextual Web search engine". Computer Networks and ISDN Systems 30: 107–117. ```ruby pr = GraphRank::PageRank.new pr.add(1,2) pr.add(1,4) pr.add(1,5) pr.add(4,5) pr.add(4,1) pr.add(4,3) pr.add(1,3) pr.add(3,1) pr.add(5,1) puts pr.calculate.inspect # => [[1, 5.99497754810465], [3, 2.694723988738302], # [5, 2.694723988738302], [4, 2.100731029131304], # [2, 2.100731029131304]] ``` Optionally, you can pass the damping factor (default = 0.85) and the convergence criterion (default = 0.01) as parameters to the PageRank constructor. Additionally, you can pass in an edge weight parameter to `#add` and it will be used in the PageRank calculation.