机器学习 第四讲 Logistic Regression和广义线性模型
需积分: 31 126 浏览量
2015-02-24
15:27:03
上传
评论
收藏 271KB PDF 举报
THE HONG KONG POLYTECHNIC UNIVERSITY, DEPARTMENT OF EIE
Lecture Notes of Machine Learning
Lecture 4 Logistic Regression
February 7, 2015
1 LOGISTIC REGRESSION
ƒc ·‚?ØL£8¯K§¿…?Ø‚5£8." y3·‚5ww©a¯K§
©a¯K †£8¯Kaq§•ØLÑÑCþ˜‡´lѧ˜‡´ëY" ·‚k'5
©a¯K§bÑÑCþy • U0 ½ö1 ü‡Š§†*þ§éu¤kÑ\Cþ§·
‚ÑF"Œ±N[0-1] ‰ŒS, •d§·‚Œ±ïáXe¼êµ
h
θ
(x) =g (θ
T
x) =
1
1 +e
−θ
T
x
Ù¥§
g (z) =
1
1 +e
−z
¡ƒ•logistic ¼ê½ösigmoid ¼ê. éN´wÑù‡¼êŠ•3(0-1)ƒm"·‚Œ±
¦logistic ¼êꕵ
g
0
(z) =
1
(1 +e
−z
)
2
e
−z
=
1
(1 +e
−z
)
·
µ
1 −
1
(1 +e
−z
)
¶
=g (z)(1 −g (z))
1
资源评论
