#?!usr/bin/python
from?numpy?import?*

#?load?‘Iris.data‘into?our?workspace
traindata?=?loadtxt（“.\\Iris.txt“delimiter?=?‘‘usecols?=?（0123）dtype?=?float）
trainlabel?=?loadtxt（“.\\Iris.txt“delimiter?=?‘‘usecols?=?（range（45））dtype?=?str）
feaname?=?[“#0““#1““#2““#3“]??#?re-defined?feature?names

#?calculate?entropy
from?math?import?log
def?calentropy（label）:
????n?=?label.size?#?the?number?of?samples
????count?=?{}?#?calculate?the?number?of?samples?belong?to?different?labels
????for?curlabel?in?label:
????????if?curlabel?not?in?count.keys（）:
????????????count[curlabel]?=?0
????????count[curlabel]?+=?1
????entropy?=?0
????for?key?in?count:
????????pxi?=?float（count[key]）/n
????????entropy?-=?pxi*log（pxi2）
????return?entropy
#?print?（calentropy（trainlabel））

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

?????文件???????4127??2016-08-21?09:34??DT_ID3_IrisData\DT_ID3_IrisData.py

?????文件???????4700??2016-08-19?22:52??DT_ID3_IrisData\Iris.txt

?????目錄??????????0??2016-08-21?10:38??DT_ID3_IrisData

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

?????????????????8827????????????????????3