logistic regression - vision...
Post on 07-Feb-2018
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Logistic Regression• Discriminative learning of Posterior
probabilities– we learn a probabilistic function
f: X → [0,1]where f is the probability of class 1 given x:
Two class case gives the decision rule:
Learning
• Gradient
!
l(D,w)= yi log f (x i,w)i=1
n
" +(1#yi)log 1# f (x i,w)( )
!
"wl(D,w)=# x i yi# f (x i,w)( )
i=1
n
$
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