function?[bestfeatT_fen]?=?choose_feat（datafeat_indexlabel）
%這里主要是用于選擇最理想的屬性
%feat_index：需要進(jìn)行比較的屬性
%data：樣本的數(shù)據(jù)?label：對(duì)應(yīng)樣本數(shù)據(jù)的標(biāo)簽

%T_fen：對(duì)應(yīng)最優(yōu)屬性的二分法的最優(yōu)分割點(diǎn)
%bestfeat：最優(yōu)屬性的索引

best_gain=0;
bestfeat=0;
%?T_fen對(duì)應(yīng)屬性獲得最大增益時(shí)的二分法取值
for?i=feat_index
????mmat=unique（data（:i））;%得到對(duì)應(yīng)屬性取值的序列
????if?length（mmat）-1==0
????????T_mat=mmat（1）;
????else
????????T_mat=ones（1length（mmat）-1）;%定義二分法的值
????????for?j=1:length（mmat）-1
????????????T_mat（j）=（mmat（j）+mmat（j+1））/2;
????????end
????end
????
????for?j=T_mat
????????Gain=Ent_cal_data（datalabelij）;
????????if?Gain>best_gain
????????????best_gain=Gain;
????????????bestfeat=i;
????????????T_fen=j;
????????end
????end
end

end

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件????????807??2020-08-07?11:02??ID3決策樹算法\choose_feat.m

?????文件???????1136??2020-08-08?09:07??ID3決策樹算法\creat_tree.m

?????文件????????360??2020-08-07?18:04??ID3決策樹算法\Ent_cal_data.m

?????文件????????491??2020-08-07?18:41??ID3決策樹算法\Ent_cal_label.m

?????文件????????193??2020-08-07?16:48??ID3決策樹算法\fen_label.m

?????文件????????257??2020-08-05?18:59??ID3決策樹算法\find_label.m

?????文件????????420??2020-08-07?17:01??ID3決策樹算法\find_mlabel.m

?????文件???????1513??2020-08-08?12:04??ID3決策樹算法\ID3_v1.m

?????文件???????4551??2020-03-05?17:12??ID3決策樹算法\iris.data

?????文件????????600??2020-08-07?11:09??ID3決策樹算法\prev.m

?????文件????????425??2020-08-07?11:10??ID3決策樹算法\print_tree.m

?????目錄??????????0??2020-09-03?16:56??ID3決策樹算法

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

????????????????10753????????????????????12