C45算法建立决策树JAVA练习

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1、以下程序是我练习写的，不一定正确也没做存储优化。侑问题请留言交流。转载请挂连接。当前的属性为:ageincomestudentcredit_rating当前的数据集为（最后一列是TARGET_VALUE）:youthhighnofairnoyouthhighnoexcellentnomiddle_agedhighnofairyesseniorlowyesfairyesseniorlowyesexcellentnomiddle_agedlowyesexcellentyesyouthmediumnofairnoyouthlowyesfairyesseniormediumyesfai

2、ryesyouthmediumyesexcellentyesmiddle_agedhighyesfairyesseniormediumnoexcellentnoC4.5建立树类packageC45Test;importjava,util.AirayList;importjava.util.List;importjava.util.Map;publicclassDecisionTree{publicTreeNodecreateDT(List〈ArrayList〈String»data,ListattributeList){System,out.println(z，

3、当前的DATA为〃);for(inti=0;itemp=data,get(i);for(intj二0;j〈temp.size();j++){System.out.print(temp,get(j)+"“)；}System,out.println();System,out.println(〃System,out.println(z，当前的ATTR为〃);for(inti二0;i

4、；}System,out.println();System,out.printin(，z〃)；TreeNodenode=newTreeNode();Stringresult=InfoGain.IsPure仃nfoGain.getTarget(data));if(result!=null){node.setNodeName(zzleafNode，/);node.setTargetFunValue(result);returnnode;}if(attributeList.size()二二0){node.setTargetFunValue(result);returnnode;}el

5、se{TnfoGaingain二newTnfoGain(data,attributeList);doublemaxGain=0.0;intattrIndex=-1;for(inti=0;i〈attributeList.size();i++){doubletempGain二gain.getGainRatio(i);if(maxGain

6、Value(attributeList.get(attrlndex));List〈ArrayList〈String>>resultDato=null;MapattrvalueMap二gain.getAttributeValue(attrlndex);for(Map.Entryentry:attrvalucMap.entrySet()){resultData二gain.getData4Value(entry.getKeyO,attrlndex);TreeNodeleafNode二null;System.out.println("

7、当前为z，+attributeList.get(attrlndex)+z，的〃+entry.getKey()+〃分支。“);if(resultDatei.size()==0){leafNode二newTreeNode();leafNode.setNodeName(attributeList.get(attrlndex));leafNode.setTargetFunValue(result);leafNode.setAttributeValue(entry.getKey());}else{fo