#?-*-?coding:?utf-8?-*-
“““
Created?on?Fri?Nov??9?15:01:36?2018

@author:?zhe

E-mail:?1194585271@qq.com
“““

import?numpy?as?np

def?loadSimpData（）:
????datMat?=?np.matrix（[[?1.???2.1]
????????[?2.???1.1]
????????[?1.3??1.?]
????????[?1.???1.?]
????????[?2.???1.?]]）
????classLabels?=?[1.0?1.0?-1.0?-1.0?1.0]
????return?datMatclassLabels

def?stumpClassify（dataMatrixdimenthreshValthreshIneq）:#just?classify?the?data
????retArray?=?np.ones（（np.shape（dataMatrix）[0]1））
????if?threshIneq?==?‘lt‘:
????????retArray[dataMatrix[:dimen]?<=?threshVal]?=?-1.0
????else:
????????retArray[dataMatrix[:dimen]?>?threshVal]?=?-1.0
????return?retArray

def?buildStump（dataArrclassLabelsD）:
????dataMatrix?=?np.mat（dataArr）;?labelMat?=?np.mat（classLabels）.T
????mn?=?np.shape（dataMatrix）
????numSteps?=?10.0;?bestStump?=?{};?bestClasEst?=?np.mat（np.zeros（（m1）））
????minError?=?np.inf?#init?error?sum?to?+infinity
????for?i?in?range（n）:#loop?over?all?dimensions
????????rangeMin?=?dataMatrix[:i].min（）;?rangeMax?=?dataMatrix[:i].max（）;
????????stepSize?=?（rangeMax-rangeMin）/numSteps
????????for?j?in?range（-1int（numSteps）+1）:#loop?over?all?range?in?current?dimension
????????????for?inequal?in?[‘lt‘?‘gt‘]:?#go?over?less?than?and?greater?than
????????????????threshVal?=?（rangeMin?+?float（j）?*?stepSize）
????????????????predictedVals?=?stumpClassify（dataMatrixithreshValinequal）#call?stump?classify?with?i?j?lessThan
????????????????errArr?=?np.mat（np.ones（（m1）））
????????????????errArr[predictedVals?==?labelMat]?=?0
????????????????weightedError?=?D.T*errArr??#calc?total?error?multiplied?by?D
????????????????print?（‘split:?dim?%d?thresh?%.2f?thresh?ineqal:?%s?the?weighted?error?is?%.3f‘?%（i?threshVal?inequal?weightedError））
????????????????if?weightedError?????????????????????minError?=?weightedError
????????????????????bestClasEst?=?predictedVals.copy（）
????????????????????bestStump[‘dim‘]?=?i
????????????????????bestStump[‘thresh‘]?=?threshVal
????????????????????bestStump[‘ineq‘]?=?inequal
????return?bestStumpminErrorbestClasEst


if?__name__==‘__main__‘:
????datMatclassLabels?=?loadSimpData（）
????D?=?np.mat（np.ones（（51））/5）
????print?（buildStump（datMatclassLabelsD））

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-11-09?15:05??Chapter7_Adaboost\1.realizeWeakclassifer\
?????文件????????2285??2018-11-09?15:24??Chapter7_Adaboost\1.realizeWeakclassifer\Adaboost.py
?????目錄???????????0??2018-11-10?15:52??Chapter7_Adaboost\2.realizeAdaboost\
?????文件????????5937??2018-11-10?16:44??Chapter7_Adaboost\2.realizeAdaboost\Adaboost.py
?????目錄???????????0??2018-11-10?16:27??Chapter7_Adaboost\3.inAction\
?????文件????????6166??2018-11-12?16:26??Chapter7_Adaboost\3.inAction\Adaboost.py
?????文件???????13614??2010-12-06?08:29??Chapter7_Adaboost\3.inAction\horseColicTest2.txt
?????文件???????60778??2010-12-06?08:26??Chapter7_Adaboost\3.inAction\horseColicTraining2.txt