利用后缀树来聚类

采用基于Java的开源搜索结果聚合引擎，Carrot2 2.0 中的后缀树算法
Carrot2 可以自动的把搜索结果归类到相应的语义类别中，这个功能是通过Carrot2一个现成的组件完成的，除此之外Carrot2 还包括了很多其他的搜索结果聚合聚类算法。

因为没有做中文分词，也没有中文的Stopword,所以我们用英文测试，实现代码


1SnippetTokenizer snippetTokenizer = new SnippetTokenizer();
2        List<DocReference> documentReferences = new ArrayList<DocReference>();      
3        List<TokenizedDocument> documents = new ArrayList<TokenizedDocument>();       
4        TokenizedDocument doc = null;
5        DocReference documentReference =  null;
6       
7        //从搜索引擎google获取100篇数据
8        {
9            String url = "http://www.google.com/search?as_q=phone&num=100&hl=en&newwindow=1&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_nlo=&as_nhi=&as_occt=any&as_dt=i&as_sitesearch=&as_rights=&safe=images";
10            byte[] pageHtml = HttpUtil.getPage(url);
11            if(pageHtml == null ) return ;           
12            try {
13                String strHtml = new String(pageHtml, "utf-8");
14                String[][] result = StringUtil.splitByReg(strHtml,"<td class=j>(.*?)<br>");
15                
16                if(result != null)
17                {      for(int i=0;i<result.length;i++)
18                        {
19                         for(int j=0;j<result[i].length;j++)
20                         {
21                             doc = snippetTokenizer
22                                .tokenize(new RawDocumentSnippet(i+"sen"+j,result[i][j].replaceAll("<[^<>]+>",""), "en"));
23                                documentReference = new DocReference(doc);
24                                documentReferences.add(documentReference);
25                                documents.add(doc);                          
26                         }
27                        }
28                }
29            } catch (UnsupportedEncodingException e) {
30                e.printStackTrace();
31            }
32        }
33
34       
35        //构建后缀树
36        final STCEngine stcEngine = new STCEngine(documentReferences);
37        stcEngine.createSuffixTree();
38        HashMap<String,String> defaults = new HashMap<String,String>();
39        defaults.put("lsi.threshold.clusterAssignment", "0.150");
40        defaults.put("lsi.threshold.candidateCluster", "0.775");
41        final StcParameters params = StcParameters.fromMap(defaults);
42        stcEngine.createBaseClusters(params);
43        stcEngine.createMergedClusters(params);
44
45        final List clusters = stcEngine.getClusters();
46        int max = params.getMaxClusters();
47
48        // Convert STC's clusters to the format required by local interfaces.
49        final List rawClusters = new ArrayList();
50        for (Iterator i = clusters.iterator(); i.hasNext() && (max > 0); max--)
51        {
52            final MergedCluster b = (MergedCluster) i.next();
53            final RawClusterBase rawCluster = new RawClusterBase();
54
55            int maxPhr = 3; // TODO: This should be a configuration parameter moved to STCEngine perhaps.
56            final List phrases = b.getDescriptionPhrases();
57            for (Iterator j = phrases.iterator(); j.hasNext() && (maxPhr > 0); maxPhr--)
58            {
59                Phrase p = (Phrase) j.next();
60                rawCluster.addLabel(p.userFriendlyTerms().trim());
61            }
62
63            for (Iterator j = b.getDocuments().iterator(); j.hasNext();)
64            {
65                final int docIndex = ((Integer) j.next()).intValue();
66                final TokenizedDocument tokenizedDoc = (TokenizedDocument) documents.get(docIndex);
67                final RawDocument rawDoc = (RawDocument) tokenizedDoc.getProperty(TokenizedDocument.PROPERTY_RAW_DOCUMENT);
68                rawCluster.addDocument(rawDoc);
69            }
70
71            rawClusters.add(rawCluster);
72        }
73       
74        //得到结果，输出
75        for (Iterator iter = rawClusters.iterator(); iter.hasNext();)
76        {
77            RawCluster cluster = (RawCluster) iter.next();
78            final List phrases = cluster.getClusterDescription();
79            for(int i=0;i<phrases.size();i++)
80                System.out.print("#"+phrases.get(i));
81            System.out.println();
82           
83        }

下面是输出聚类phone的结果，还不错
#phone
#Phone Number
#yellow pages
#mobile phone
#cell phone
#Phone Book
#area code
#Business
#services
#Wireless
#people
#directory
#telephone
#address
#online

评论

1 楼 yajie 2009-05-22  

有点意思，受教了！