xiaolongliang / Decision-tree

code of ID3、CART, the data is breast cancer, ID3 data has been processed,CART is original breast cancer data

Decision-tree

code of ID3、CART

一、 File Description：

brease_raw:乳腺癌原始数据

breast_processed：处理过的10维乳腺癌数据

二、 Main Function   ID3: main function introduce

1. 计算经验熵：def calcShannonEnt(dataSet)

2. 计算信息增益

   def splitDataSet(dataSet, axis, value):按照给定特征划分数据集

   def chooseBestFeatureToSplit(dataSet):计算信息增益

3. 统计classList中出现此处最多的元素(类标签)： def majorityCnt(classList)

4. 建树：def majorityCnt(classList):def createTree(dataSet, labels, featLabels)

CART: main function introduce

1. 载入数据:def loadDataSet(self, fileName)

2. 切分数据集为两个子集: def binSplitDataSet(dataSet, feature, value)

3. 二元切分: def chooseBestSplit(dataSet, leafType=regLeaf, errType=regErr, ops=(1,4))

4. 构建tree: def createTree(dataSet, leafType=regLeaf, errType=regErr, ops=(1,4))