意思決定ツリー-機械学習実戦完全版(python 3)

import matplotlib.pyplot as plt
# boxstyle       fc      sawtooth    
'''xy     
xytext     
    ：       ，           ？
  ：arrowstyle="maxDepth: maxDepth=thisDepth
    return maxDepth
def retrieveTree(i):
    listOfTrees=[{'no surfacing':{0:'no',1:{'flippers':{0:'no',1:'yes'}}}},\
                 {'no surfacing':{0:'no',1:{'flippers':{0:{'head':{0:'no',1:'yes'}},1:'no'}}}}]
    return listOfTrees[i]
def plotMidText(cntrPt,parentPt,txtString):#    cntrPt parentPt       ，    txtString   #parentPt           （    ），cntrPt      ，     

    xMid=(parentPt[0]-cntrPt[0])/2.0+cntrPt[0]#x   
    yMid=(parentPt[1]-cntrPt[1])/2.0+cntrPt[1]#y   
    createPlot.ax1.text(xMid,yMid,txtString)# (xMid, yMid)   txtString
def plotTree(myTree,parentPt,nodeTxt):  # nodeTxt        
    numLeafs=getNumLeafs(myTree)
    depth=getTreeDepth(myTree)
    firstSides = list(myTree.keys())
    firstStr = firstSides[0]
    cntrPt=(plotTree.xOff+(1.0+float(numLeafs))/2.0/plotTree.totalW,plotTree.yOff)#cntrPt                  
    # plotTree.xOff plotTree.yOff              ，plotTree.totalW       ，    
    #cntrPt                   plotTree   ，       
    # cntrPt = (plotTree.xOff + (1.0 + float(numLeafs)) / 2.0 / plotTree.totalW, plotTree.yOff)
    # numLeafs             。                  
    # plotTree.xOff + (1.0 + float(numLeafs)) / 2.0 / plotTree.totalW    
    # 1.0 + numLeafs        ，   
    # plotTree.xOff + float(numLeafs) / 2.0 / plotTree.totalW + 1.0 / 2.0 / plotTree.totalW
    # plotTree.xOff + 1 / 2 * float(numLeafs) / plotTree.totalW + 0.5 / plotTree.totalW
    #   xOff      - 0.5 / plotTree.totalW ，     0.5 / plotTree.tatalW ，
    #        。  cntrPt   x               '''
    plotMidText(cntrPt,parentPt,nodeTxt)#    
    plotNode(firstStr,cntrPt,parentPt,decisionNode)#firstStr        ，cntrPt       ，
                                                   # parentPt           ，decisionNode     
    secondDict=myTree[firstStr]#  
    plotTree.yOff=plotTree.yOff-1.0/plotTree.totalD#totalD       ，      ,    1
    for key in secondDict.keys():
        if type(secondDict[key]).__name__=='dict':
            plotTree(secondDict[key],cntrPt,str(key))
        else:
            plotTree.xOff=plotTree.xOff+1.0/plotTree.totalW#x        
            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#      

def createPlot(inTree):#    ，   plotTree,plotTree         
    fig=plt.figure(1,facecolor='white')#      ，     
    fig.clf()#    
    axprops=dict(xticks=[],ytichs=[])#       ，   
    createPlot.ax1 = plt.subplot(111, frameon=False)
    #createPlot.ax1=plt.subplot(111,frameon=False,**axprops)#  x、y ,xticks=[],ytichs=[]   ，          #**          
    # ax1   createPlot     ，                         
    # createPlot.ax1 = plt.subplot(111, frameon = False, **axprops) #frameon           ，    ，111  1X1  ，   
    plotTree.totalW=float(getNumLeafs(inTree))
    plotTree.totalD=float(getTreeDepth(inTree))
    plotTree.xOff=-0.5/plotTree.totalW#           1/totalW , 2/totalW, 3/totalW, …, 1   ，
                                 #           ，           ，    0.5 / totalW 。
                                 #   createPlot   ，    plotTree.xOff    -0.5/plotTree.totalW。
                                #      xOff + 1/totalW ，    1        
    plotTree.yOff=1.0               #yOff     1，       ，      1 / totalD
    plotTree(inTree,(0.5,1.0),'')
    plt.show()