‘‘‘
Created?on?Oct?14?2010

@author:?Peter?Harrington
‘‘‘
import?matplotlib.pyplot?as?plt

decisionNode?=?dict（boxstyle=“sawtooth“?fc=“0.8“）
leafNode?=?dict（boxstyle=“round4“?fc=“0.8“）
arrow_args?=?dict（arrowstyle=“<-“）

def?getNumLeafs（myTree）:
????numLeafs?=?0
????firstStr?=?myTree.keys（）[0]
????secondDict?=?myTree[firstStr]
????for?key?in?secondDict.keys（）:
????????if?type（secondDict[key]）.__name__==‘dict‘:#test?to?see?if?the?nodes?are?dictonaires?if?not?they?are?leaf?nodes
????????????numLeafs?+=?getNumLeafs（secondDict[key]）
????????else:???numLeafs?+=1
????return?numLeafs

def?getTreeDepth（myTree）:
????maxDepth?=?0
????firstStr?=?myTree.keys（）[0]
????secondDict?=?myTree[firstStr]
????for?key?in?secondDict.keys（）:
????????if?type（secondDict[key]）.__name__==‘dict‘:#test?to?see?if?the?nodes?are?dictonaires?if?not?they?are?leaf?nodes
????????????thisDepth?=?1?+?getTreeDepth（secondDict[key]）
????????else:???thisDepth?=?1
????????if?thisDepth?>?maxDepth:?maxDepth?=?thisDepth
????return?maxDepth

def?plotNode（nodeTxt?centerPt?parentPt?nodeType）:
????createPlot.ax1.annotate（nodeTxt?xy=parentPt??xycoords=‘axes?fraction‘
?????????????xytext=centerPt?textcoords=‘axes?fraction‘
?????????????va=“center“?ha=“center“?bbox=nodeType?arrowprops=arrow_args?）
????
def?plotMidText（cntrPt?parentPt?txtString）:
????xMid?=?（parentPt[0]-cntrPt[0]）/2.0?+?cntrPt[0]
????yMid?=?（parentPt[1]-cntrPt[1]）/2.0?+?cntrPt[1]
????createPlot.ax1.text（xMid?yMid?txtString?va=“center“?ha=“center“?rotation=30）

def?plotTree（myTree?parentPt?nodeTxt）:#if?the?first?key?tells?you?what?feat?was?split?on
????numLeafs?=?getNumLeafs（myTree）??#this?determines?the?x?width?of?this?tree
????depth?=?getTreeDepth（myTree）
????firstStr?=?myTree.keys（）[0]?????#the?text?label?for?this?node?should?be?this
????cntrPt?=?（plotTree.xOff?+?（1.0?+?float（numLeafs））/2.0/plotTree.totalW?plotTree.yOff）
????plotMidText（cntrPt?parentPt?nodeTxt）
????plotNode（firstStr?cntrPt?parentPt?decisionNode）
????secondDict?=?myTree[firstStr]
????plotTree.yOff?=?plotTree.yOff?-?1.0/plotTree.totalD
????for?key?in?secondDict.keys（）:
????????if?type（secondDict[key]）.__name__==‘dict‘:#test?to?see?if?the?nodes?are?dictonaires?if?not?they?are?leaf?nodes???
????????????plotTree（secondDict[key]cntrPtstr（key））????????#recursion
????????else:???#it‘s?a?leaf?node?print?the?leaf?node
????????????plotTree.xOff?=?plotTree.xOff?+?1.0/plotTree.totalW
????????????plotNode（secondDict[key]?（plotTree.xOff?plotTree.yOff）?cntrPt?leafNode）
????????????plotMidText（（plotTree.xOff?plotTree.yOff）?cntrPt?str（key））
????plotTree.yOff?=?plotTree.yOff?+?1.0/plotTree.totalD
#if?you?do?get?a?dictonary?you?know?it‘s?a?tree?and?the?first?element?will?be?another?dict

def?createPlot（inTree）:
????fig?=?plt.figure（1?facecolor=‘white‘）
????fig.clf（）
????axprops?=?dict（xticks=[]?yticks=[]）
????createPlot.ax1?=?plt.subplot（111?frameon=False?**axprops）????#no?ti

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????101??2010-10-16?09:36??決策樹+python\classifierStorage.txt

?????文件????????795??2012-01-09?21:40??決策樹+python\lenses.txt

?????文件???????3911??2012-01-09?21:39??決策樹+python\treePlotter.py

?????文件???????3399??2012-01-09?21:39??決策樹+python\treePlotter.pyc

?????文件???????4170??2011-12-11?20:40??決策樹+python\trees.py

?????文件???????3692??2012-01-09?21:06??決策樹+python\trees.pyc

?????目錄??????????0??2018-07-23?10:12??決策樹+python

-----------?---------??----------?-----??----

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