#?-*-?coding:?utf-8?-*-
“““
Created?on?Fri?Sep?02?14:36:44?2011

@author:?Liping
“““

from?__future__?import?division
import?numpy?as?np

class?naive_bayes:
????def?__init__（self）:
????????“““?Constructor?“““
????????
????def?read_data（selffilename）:
????????fid?=?open（filename“r“）
????????data?=?[]
????????d?=?[]
????????for?line?in?fid.readlines（）:
????????????d.append（line.strip（））
????????for?d1?in?d:
????????????data.append（d1.split（““））
????????fid.close（）

????????self.featureNames?=?data[0]
????????self.featureNames?=?self.featureNames[:-1]####################
????????data?=?data[1:]
????????self.classes?=?[]
????????for?d?in?range（len（data））:
????????????self.classes.append（data[d][-1]）
????????????data[d]?=?data[d][:-1]

????????return?dataself.classesself.featureNames?
?
????#Calculate?the?Prob.?of?class:cls
????def?NB（selfTr_dataTr_classesTe_data）:
????????cls_vals?=?[]
????????for?aclass?in?Tr_classes:
????????????if??cls_vals.count（aclass）==0:
?????????????????cls_vals.append（aclass）?#?Class?names
????????
????????#calculate?the?probability?for?each?class
????????cnt?=?[0]*len（cls_vals）
????????proba_cla?=?[0]*len（cls_vals）
????????
????????for?i?in?range（len（cls_vals））:
????????????for?aclass?in?Tr_classes:
????????????????if??cls_vals[i]?==?aclass:
?????????????????????cnt[i]?+=?1?#?The?number?of?data?for?each?class
????????????#sub_sum[i]?=?cnt[i]

????????????proba_cla[i]?=?float（cnt[i]/len（Tr_data））
?
????????#return?cls_valscntproba_cla
????????
????#Calculate?the?Prob（attr|cls）
????#def?PT（selfdataclasses）:
????????num_uni_attr?=?[]
????????pro_uni_attr_cla?=?[]
????????vol_all_attr?=?[]
????????vol_uni_attr?=?[]
????????L?=?[]
????????
????????vol_all_attr?=?np.array（Tr_data）.T

????????for?i?in?range（len（vol_all_attr））:
????????????a?=?np.unique（vol_all_attr[i]）
????????????vol_uni_attr.append（a）?#?The?unique?values?of?each?feature
????????
????????‘‘‘define?the?pro_uni_attr_cla:?The?probabilites?of?diffirent?values?of?each?attribute?for?diffirent?classes??‘‘‘??
????????‘‘‘this?is?very?important!!!!!!!?How?to?dynamic?create?a?multi-dimensional?array!‘‘‘
????????x?=?len（cls_vals）
????????y?=?len（vol_uni_attr）
????????pro_uni_attr_cla?=?[[None]*y?for?_?in