diff --git a/src/python/09.RegTrees/TreeNode.py b/src/python/09.RegTrees/TreeNode.py deleted file mode 100644 index c6e76583..00000000 --- a/src/python/09.RegTrees/TreeNode.py +++ /dev/null @@ -1,16 +0,0 @@ -#!/usr/bin/python -# coding:utf8 - -''' -Created on 2017-03-06 -Update on 2017-03-06 -@author: jiangzhonglian -''' - - -class treeNode(): - def __init__(self, feat, val, right, left): - self.featureToSplitOn = feat - self.valueOfSplit = val - self.rightBranch = right - self.leftBranch = left diff --git a/src/python/12.FrequentPattemTree/fpGrowth.py b/src/python/12.FrequentPattemTree/fpGrowth.py index 75f07aea..193fc6f8 100644 --- a/src/python/12.FrequentPattemTree/fpGrowth.py +++ b/src/python/12.FrequentPattemTree/fpGrowth.py @@ -7,9 +7,7 @@ FP-Growth FP means frequent pattern the FP-Growth algorithm needs: 1. FP-tree (class treeNode) 2. header table (use dict) - This finds frequent itemsets similar to apriori but does not find association rules. - @author: Peter/片刻 ''' print(__doc__) @@ -56,53 +54,120 @@ def createInitSet(dataSet): return retDict -def createTree(dataSet, minSup=1): #create FP-tree from dataset but don't mine - """ +# this version does not use recursion +def updateHeader(nodeToTest, targetNode): + """updateHeader(更新头指针，添加targetNode到nodeToTest的nodeLink上面) + 从头指针的nodeLink开始，一直沿着nodeLink直到到达链表末尾。这就是链表。 + 性能：如果链表很长可能会遇到迭代调用的次数限制。 + + Args: + nodeToTest 头节点 + targetNode 目标节点 """ - headerTable = {} - #go over dataSet twice - for trans in dataSet:#first pass counts frequency of occurance - for item in trans: - headerTable[item] = headerTable.get(item, 0) + dataSet[trans] - for k in headerTable.keys(): #remove items not meeting minSup - if headerTable[k] < minSup: - del(headerTable[k]) - freqItemSet = set(headerTable.keys()) - #print 'freqItemSet: ',freqItemSet - if len(freqItemSet) == 0: return None, None #if no items meet min support -->get out - for k in headerTable: - headerTable[k] = [headerTable[k], None] #reformat headerTable to use Node link - #print 'headerTable: ',headerTable - retTree = treeNode('Null Set', 1, None) #create tree - for tranSet, count in dataSet.items(): #go through dataset 2nd time - localD = {} - for item in tranSet: #put transaction items in order - if item in freqItemSet: - localD[item] = headerTable[item][0] - if len(localD) > 0: - orderedItems = [v[0] for v in sorted(localD.items(), key=lambda p: p[1], reverse=True)] - updateTree(orderedItems, retTree, headerTable, count)#populate tree with ordered freq itemset - return retTree, headerTable #return tree and header table + # Do not use recursion to traverse a linked list! + while (nodeToTest.nodeLink is not None): + nodeToTest = nodeToTest.nodeLink + nodeToTest.nodeLink = targetNode def updateTree(items, inTree, headerTable, count): - if items[0] in inTree.children:#check if orderedItems[0] in retTree.children - inTree.children[items[0]].inc(count) #incrament count - else: #add items[0] to inTree.children + """updateTree(更新FP-tree，第二次遍历) + + Args: + items 满足minSup 排序后的元素数组（大到小的排序） + inTree 空的Tree对象 + headerTable 满足minSup {所有的元素+(value, treeNode)} + count 原数据集中每一组Kay出现的次数 + """ + # 判断满足minSup排序后的第一个元素，是否是inTree的子节点 + if items[0] in inTree.children: + # 如果是，那么这个子节点的key元素添加count次 + inTree.children[items[0]].inc(count) + else: + # 如果不存在子节点，我们为该inTree添加子节点 inTree.children[items[0]] = treeNode(items[0], count, inTree) - if headerTable[items[0]][1] == None: #update header table + # 如果满足minSup的dist字典的value值第二位为null， 我们就设置该元素为 本节点对应的tree节点 + # 如果元素第二位不为null，我们就更新header节点 + if headerTable[items[0]][1] is None: headerTable[items[0]][1] = inTree.children[items[0]] else: updateHeader(headerTable[items[0]][1], inTree.children[items[0]]) - if len(items) > 1:#call updateTree() with remaining ordered items + if len(items) > 1: + # print 'items[1::]=', items[1::] updateTree(items[1::], inTree.children[items[0]], headerTable, count) -def updateHeader(nodeToTest, targetNode): #this version does not use recursion - while (nodeToTest.nodeLink != None): #Do not use recursion to traverse a linked list! - nodeToTest = nodeToTest.nodeLink - nodeToTest.nodeLink = targetNode +def createTree(dataSet, minSup=1): + """createTree(生成FP-tree，第一次遍历) + + Args: + dataSet dist字典对象 + minSup 最小的支持度 + Returns: + retTree FP-tree + headerTable 满足minSup {所有的元素+(value, treeNode)} + """ + # 创建一个满足支持度>=minSup的dist字典 + headerTable = {} + # 循环得到dist字典所有的key + for trans in dataSet: + # 对所有的key进行循环，得到key里面的所有元素 + for item in trans: + # 存储每个元素和它对应的次数： 本身+dataSet该元素出现的次数 + headerTable[item] = headerTable.get(item, 0) + dataSet[trans] + # 循环所有元素出现的次数，然后remove到小于minSup的元素 + for k in headerTable.keys(): + if headerTable[k] < minSup: + del(headerTable[k]) + + # 求出满足minSup元素的集合 + freqItemSet = set(headerTable.keys()) + # 如果不存在满足minSup的元素就直接返回None + if len(freqItemSet) == 0: + return None, None + for k in headerTable: + # reformat headerTable to use Node link + # value值为一个元组 + headerTable[k] = [headerTable[k], None] + + # create tree + retTree = treeNode('Null Set', 1, None) + for tranSet, count in dataSet.items(): + localD = {} + for item in tranSet: + # 判断是否在满足minSup的集合中 + if item in freqItemSet: + # print 'headerTable[item][0]=', headerTable[item][0], headerTable[item] + localD[item] = headerTable[item][0] + if len(localD) > 0: + # p=key,value; 所以是通过value值的大小，进行从大到小进行排序 + # orderedItems表示取出元组的key值，也就是字母本身，但是字母本身是存在顺序的 + orderedItems = [v[0] for v in sorted(localD.items(), key=lambda p: p[1], reverse=True)] + # print 'sorted(localD.items(), key=lambda p: p[1], reverse=True)]=', sorted(localD.items(), key=lambda p: p[1], reverse=True) + # print 'orderedItems=', orderedItems + + # 使用有序freq项集来填充树 + updateTree(orderedItems, retTree, headerTable, count) + + return retTree, headerTable + + +def ascendTree(leafNode, prefixPath): #ascends from leaf node to root + if leafNode.parent is not None: + prefixPath.append(leafNode.name) + ascendTree(leafNode.parent, prefixPath) + + +def findPrefixPath(basePat, treeNode): #treeNode comes from header table + condPats = {} + while treeNode is not None: + prefixPath = [] + ascendTree(treeNode, prefixPath) + if len(prefixPath) > 1: + condPats[frozenset(prefixPath[1:])] = treeNode.count + treeNode = treeNode.nodeLink + return condPats if __name__ == "__main__": @@ -114,28 +179,19 @@ if __name__ == "__main__": # load样本数据 simpDat = loadSimpDat() - print simpDat + # print simpDat, '\n' # 重新装载 frozen set 格式化样本数据，用dist存储数据和对应的次数 initSet = createInitSet(simpDat) - print initSet + # print initSet + + # 创建FP树 + myFPtree, myHeaderTab = createTree(initSet, 3) + myFPtree.disp() + # print myHeaderTab -def ascendTree(leafNode, prefixPath): #ascends from leaf node to root - if leafNode.parent != None: - prefixPath.append(leafNode.name) - ascendTree(leafNode.parent, prefixPath) -def findPrefixPath(basePat, treeNode): #treeNode comes from header table - condPats = {} - while treeNode != None: - prefixPath = [] - ascendTree(treeNode, prefixPath) - if len(prefixPath) > 1: - condPats[frozenset(prefixPath[1:])] = treeNode.count - treeNode = treeNode.nodeLink - return condPats - def mineTree(inTree, headerTable, minSup, preFix, freqItemList): bigL = [v[0] for v in sorted(headerTable.items(), key=lambda p: p[1])]#(sort header table)