使用Weka进行参数优化和属性选择

Question

我想在J48中设置-C参数并运行三个存储在哈希表中的特征选择算法。我想比较三者的表现，如精确度，真正积极，真正消极，F1等。但是，当我运行所有功能选择算法时，它们会返回相同的输出....我做错了什么？

Hashtable<String, ASEvaluation> search=new Hashtable<String, ASEvaluation>(); 

    Instances training_data = new Instances(new BufferedReader(
      new FileReader("test.arff"))); 
    training_data.setClassIndex(training_data.numAttributes() - 1); 
    topAttributes = new int[training_data.numAttributes()]; 

    AttributeSelectedClassifier classifier = new AttributeSelectedClassifier(); 
AttributeSelection attsel = new AttributeSelection(); 

    search.put("Infogain", new InfoGainAttributeEval()); 
    search.put("SymmetricalUncertAttribute",new SymmetricalUncertAttributeEval()); 
    search.put("Chisquared",new ChiSquaredAttributeEval()); 

    for(String key : search.keySet()) { 



     try{ 
      Ranker attribute_search = new Ranker(); 
       J48 base = new J48(); 
      CVParameterSelection ps = new CVParameterSelection(); 
       ps.setClassifier(base); 
       ps.setNumFolds(5); 
       ps.addCVParameter("C 0.1 0.5 5"); 
       ps.buildClassifier(training_data); 

       System.out.println("---------------- " + search.get(key).toString() + " ----------------"); 

       classifier.setClassifier(ps);      
      classifier.setEvaluator(search.get(key)); 
      classifier.setSearch(attribute_search); 

        attsel.setEvaluator(search.get(key)); 
        attsel.setSearch(attribute_search); 
        attsel.setInputFormat(training_data); 



      Evaluation evaluation = new Evaluation(training_data); 
      evaluation.crossValidateModel(ps, training_data, 10, new Random(1)); 
      System.out.println("\nevaluation ->");   
      System.out.println(evaluation.toSummaryString()); 
      System.out.println("MAE: " + evaluation.meanAbsoluteError()); 

     } catch(Exception e) { 
      e.printStackTrace(); 
     } 
    } 

Answer 1

我不知道你是怎么做到的。但你有没有尝试过使用网格搜索？