后剪枝添加完成

src/main/java/org/wlld/randomForest/Tree.java

@@ -14,15 +14,17 @@ public class Tree {//决策树
     private Map<String, List<Integer>> table;//总样本
     private Node rootNode = new Node();//根节点
     private List<Integer> endList;//最终结果分类
+    private List<Node> lastNodes = new ArrayList<>();//最后一层节点集合
 
     private class Node {
-        private boolean isEnd = false;
+        private boolean isEnd = false;//是否是最底层
         private List<Integer> fatherList;//父级样本
         private Set<String> attribute;//当前可用属性
         private String key;//该节点分类属性
         private int typeId;//该节点该属性分类的Id值
         private List<Node> nodeList;//下属节点
-        private int type;
+        private int type;//最底层的类别
+        private Node fatherNode;//父级节点
     }
 
     private class Gain {
@@ -142,6 +144,9 @@ public class Tree {//决策树
             }
             node.key = key;
             List<Node> nodeList = nodeMap.get(key);
+            for (int j = 0; j < nodeList.size(); j++) {//儿子绑定父亲关系
+                nodeList.get(j).fatherNode = node;
+            }
             for (int j = 0; j < nodeList.size(); j++) {
                 Node node1 = nodeList.get(j);
                 node1.nodeList = createNode(node1);
@@ -151,6 +156,7 @@ public class Tree {//决策树
             //判断类别
             node.isEnd = true;//叶子节点
             node.type = getType(fatherList);
+            lastNodes.add(node);//将全部最后一层节点集合
             return null;
         }
     }
@@ -187,6 +193,10 @@ public class Tree {//决策树
         return attriBute;
     }
 
+    public void judge() {//进行类别判断
+
+    }
+
     public void study() throws Exception {
         if (dataTable != null) {
             endList = dataTable.getTable().get(dataTable.getKey());
@@ -200,8 +210,68 @@ public class Tree {//决策树
             rootNode.fatherList = list;//当前父级样本
             List<Node> nodeList = createNode(rootNode);
             rootNode.nodeList = nodeList;
+            //进行后剪枝
+            for (Node lastNode : lastNodes) {
+                prune(lastNode.fatherNode);
+            }
+            lastNodes.clear();
         } else {
             throw new Exception("dataTable is null");
         }
     }
+
+    private void prune(Node node) {//执行剪枝
+        if (node != null && !node.isEnd) {
+            List<Node> listNode = node.nodeList;//子节点
+            if (isPrune(node, listNode)) {//剪枝
+                deduction(node);
+                prune(node.fatherNode);
+            }
+        }
+    }
+
+    private void deduction(Node node) {
+        node.isEnd = true;
+        node.nodeList = null;
+        node.type = getType(node.fatherList);
+    }
+
+    private boolean isPrune(Node father, List<Node> sonNodes) {
+        boolean isRemove = false;
+        List<Integer> typeList = new ArrayList<>();
+        for (int i = 0; i < sonNodes.size(); i++) {
+            Node node = sonNodes.get(i);
+            List<Integer> list = node.fatherList;
+            typeList.add(getType(list));
+        }
+        int fatherType = getType(father.fatherList);
+        int nub = getRightPoint(father.fatherList, fatherType);
+        //父级该样本正确率
+        double rightFather = ArithUtil.div(nub, father.fatherList.size());
+        int rightNub = 0;
+        int rightAllNub = 0;
+        for (int i = 0; i < sonNodes.size(); i++) {
+            Node node = sonNodes.get(i);
+            List<Integer> list = node.fatherList;
+            int right = getRightPoint(list, typeList.get(i));
+            rightNub = rightNub + right;
+            rightAllNub = rightAllNub + list.size();
+        }
+        double rightPoint = ArithUtil.div(rightNub, rightAllNub);//子节点正确率
+        if (rightPoint <= rightFather) {
+            isRemove = true;
+        }
+        return isRemove;
+    }
+
+    private int getRightPoint(List<Integer> types, int type) {
+        int nub = 0;
+        for (int index : types) {
+            int end = endList.get(index);
+            if (end == type) {
+                nub++;
+            }
+        }
+        return nub;
+    }
 }

src/test/java/org/wlld/Food.java

@@ -8,8 +8,26 @@ package org.wlld;
 public class Food {
     private int height;//身高
     private int weight;//体重
+    private int h1;
+    private int h2;
     private int sex;//性别 1男 2女
 
+    public int getH1() {
+        return h1;
+    }
+
+    public void setH1(int h1) {
+        this.h1 = h1;
+    }
+
+    public int getH2() {
+        return h2;
+    }
+
+    public void setH2(int h2) {
+        this.h2 = h2;
+    }
+
     public int getHeight() {
         return height;
     }

src/test/java/org/wlld/MatrixTest.java

@@ -23,16 +23,21 @@ public class MatrixTest {
         column.add("height");
         column.add("weight");
         column.add("sex");
+        column.add("h1");
+        column.add("h2");
         DataTable dataTable = new DataTable(column);
         dataTable.setKey("sex");
         Random random = new Random();
-        for (int i = 0; i < 10; i++) {
+        int cla = 3;
+        for (int i = 0; i < 50; i++) {
             Food food = new Food();
-            food.setHeight(random.nextInt(2));
-            food.setWeight(random.nextInt(2));
-            food.setSex(random.nextInt(2));
-            System.out.println("index==" + i + ",height==" + food.getHeight() +
-                    ",weight==" + food.getWeight() + ",sex==" + food.getSex());
+            food.setHeight(random.nextInt(cla));
+            food.setWeight(random.nextInt(cla));
+            food.setSex(random.nextInt(cla));
+            food.setH1(random.nextInt(cla));
+            food.setH2(random.nextInt(cla));
+//            System.out.println("index==" + i + ",height==" + food.getHeight() +
+//                    ",weight==" + food.getWeight() + ",sex==" + food.getSex());
             dataTable.insert(food);
         }
         Tree tree = new Tree(dataTable);